M.D. M.Sc Arnaud Depeyre
email: depeyrearnaud@gmail.fr

M.D. M.Sc Matthias Schlund

Constance Delmotte

M.D. g Vincent Dupuch

N Pham Dang

M.D Isabelle Barthélémy

M.D Nathalie Pham Dang

Extracorporeal septorhinoplasty: Technical note

de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Deviation of nasal septum influences both function and shape of the nose. It could alone or associated with other nasal deformities be responsible for deviation of the entire nasal unit. Severe nasal septal abnormalities can be encountered in traumatic and iatrogenic context but also in cleft lip and palate patients [START_REF] Sykes | The importance of the nasal septum in the deviated nose[END_REF]. Precise diagnosis of deviated nose due to severe septal deformity is essential and should guide the adequate treatment plan as classical septoplasty techniques could not properly correct these deformities and restore satisfactory nasal shape and function [START_REF] Gubisch | Twenty-five years experience with extracorporeal septoplasty[END_REF].

The concept of extracorporeal septoplasty was first described by King and Ashley to correct these severe nasal septal deviations [START_REF] King | The correction of the internally and externally deviated nose[END_REF]. They take out the whole septum, resculpt it to straighten it and finally replant it. Within the last past decades, the concept of extracorporeal septoplasty has been thoroughly revisited and refined to avoid aesthetic complications described with this technique such as saddle nose or nasal dorsum irregularities [START_REF] Gubisch | Twenty-five years experience with extracorporeal septoplasty[END_REF][START_REF] Gubisch | Treatment of the scoliotic nose with extracorporeal septoplasty[END_REF][START_REF] Rezaeian | New Suturing Techniques to Reconstruct the Keystone Area in Extracorporeal Septoplasty[END_REF]. While management of the keystone area between bony and reconstructed cartilaginous dorsum has undergone profound changes, it remains challenging and considered as technically demanding to execute [START_REF] Most | Anterior septal reconstruction: outcomes after a modified extracorporeal septoplasty technique[END_REF].

The aim of this article is to present the surgical procedure and the different suture techniques of the replanted septum and to discuss indications, advantages and limits of the extracorporeal septorhinoplasty.

Technical Note

Preoperative assessment

The usual clinical examination was completed by a functional evaluation with rhinomanometry, which gave an objective evaluation of the nasal airflow.

A complete facial CT scan was prescribed to localize deviation of nasal septum in cephalo-caudal and antero-posterior axis, and to appreciate the degree of septal dislocation and ossification in case of traumatic nose (Please insert Figure 1). This information was used to prepare at best neoseptum reconstruction

Installation

The patient was placed in dorsal decubitus and surgery was performed under general anesthesia with a pre-shaped oral intubation.

Surgical approach, incision and exposure

Only columella and internal nasal septum underwent local anesthesia by lidocaine with 1:200000 epinephrine, followed by topical lidocaine with naphazoline-saturated cotton pledgets. A midcolumellar incision (stair step or inverted V), with a No 11 blade, prolonged bilaterally with marginal incisions was realized (Please insert Figure 2). Cartilaginous tip dissection was performed in the subperichondral plane and was extended upward to the bony nasal vault.

Septum dissection and dislocation

Septum dissection and dislocation, were performed in 3 steps (incision and exposition, dissection, dislocation and separation).

-Incision and exposition Membranous septum was incised to expose the anterior edge of nasal cartilaginous septum.

Then a bilateral perichondrial flap from the superoexternal surface of upper lateral cartilages was safely dissected and preserved to cover the replanted neoseptum at the end of the procedure (Please insert Figure 3A).

-Dissection Subperichondrial dissection of the nasal septum was performed at first on the concave side to limit the risk of mucosal injury and secondly on the other side. A bilateral extramucosal dissection of the junction of the border between the dorsal septum and upper lateral cartilages was realized to preserve an intact mucosal wall. Dorsal septum and upper lateral cartilages could, at this step, be safely separated (Please insert Figure 3B). Septum dissection was extended to the posterior and inferior junction with the vomer and maxilla up to the anterior nasal spine.

-Dislocation and separation An upper separation of the nasal septum was performed. Different situations could be encountered depending on septal deviation level and dorsal hump reduction planning.

• If a high separation was recommended; the bony septum was vertically fractured as far as possible posteriorly by piezosurgery. If dorsal hump reduction was not performed, a paramedian osteotomy could be realized with the piezoelectric instrument to remove the bony septum from the dorsum. Afterwards, an « en bloc » removal of the bonycartilaginous septum partition was achieved (Please insert Figure 3C).

• If a low separation was recommended, when just a marginal anterior and caudal deviation of nasal septum was present, a partial extracorporeal septorhinoplasty could be performed and the septal cartilaginous section level was adapted at a lower level to treat extracorporeally the partial deviated septum (Please insert Figure 3D).

Extracorporeal septal remodeling

The ideal reconstructed septum should be as large as possible with stable upper and anterior borders. Different situations could be encountered.

• In case of sufficient quantities of usable bony cartilaginous septum, redundant and dislocated pieces could be excised and straight ones kept to be sutured together providing a stable reconstructed nasal neoseptum. If needed, the cartilage and bone could be smoothed with a diamented piezotome insert, which might straighten the bent septum. If the cartilage became straight but thin and unstable with this procedure, some pieces of the perpendicular plate could be sutured as a double layer onto the cartilaginous septum to create a stiffer frame.

• In case of preoperative nasal valve impairment but also to prevent it postoperatively, a cartilaginous spreader graft could be fixed to the upper border of the neoseptum (Please insert Figure 4A).

• In post-traumatic cases with multiple fracture sites and when exceptionally, quantity of straighten septal cartilage was insufficient; a polydioxanone (PDS) foil could be used to provide a template to stabilize cartilaginous pieces that were sutured on. Septal reconstruction could also be performed from rib cartilage allowing straightness and a large quantity of cartilage available to harvest.

Reimplantation and fixation of the neoseptum

The neoseptum is then replanted in its perichondrial envelope that was to say between the subperichondrial and subperiosteal layers dissected before. To insure a long-term stability, the most important at this step was to strongly fix the neoseptum. Two techniques were commonly used.

• If nasal bones were sufficiently large and if nasal osteotomies were performed, the technique called « criss-cross » suture was preferred. A drill hole was marked and created through the caudal and medial end of nasal bone. Fixation of neoseptum was then realized with a 4.0 non-absorbable round needle suture passing through the upper part of upper lateral cartilages, the neoseptum and the drill holes previously described (Please insert Figure 4B).

• If the « criss-cross » suture was not possible or in case of partial extracorporeal septorhinoplasty, a fixation by multiple horizontal « U-shaped » 4.0 non-absorbable round needle sutures to upper lateral cartilages was performed (Please insert Figure 4C).

After positioning anterior and caudal part of the reconstructed septum on the median line, face to anterior nasal spine, a double 3.0 non-absorbable round needle suture was performed passing through periosteum of the premaxilla and the neoseptum. If needed, a hole was drilled to pass the needle through and to anchor it more strongly to anterior nasal spine.

Camouflage techniques and closure

The two perichondrial flaps dissected at the step of separation and dissection of septum and upper lateral cartilages were sutured on the median line. Suture was performed with 6.0 absorbable stitches (Please insert Figure 4D). If this technique was not sufficient, cartilage onlay graft, diced cartilage embedded in fascia or temporal fascia flap could also be used to smooth the dorsal surface.

Surgical approach closure was realized with 5.0 absorbable sutures on intranasal incisions and 6.0 non-absorbable sutures on skin incision.

To protect the surgical result, nasal wall was lined with a combined forehead and nasal splint and neoseptum was also encased by intranasal silicone splints during 15 days, preventing any shifting with movements during postoperative period.

Discussion

Severe deviations of nasal septum, especially when the anterior and superior, or caudal parts are involved, represent one of the most difficult challenges for nasal surgeons [START_REF] Sykes | The importance of the nasal septum in the deviated nose[END_REF]. In these cases, conservative surgical procedures with cartilage radial incisions or removal of deviated segments may give unsatisfactory result. They can lead to relapse because of the strong tendency of cartilage to return to its original shape or to near-total cartilage resection, also resulting in postoperative saddling of the middle vault and internal valve collapse [START_REF] Tasca | Extracorporeal septoplasty with internal nasal valve stabilisation[END_REF].

Simple replacement of cartilage segments between the two mucoperichondrial layers, as suggested by other authors, is a highly imprecise maneuver that fails to reinforce anterior and superior septum and may create postoperative reduplication of the cartilage with nasal obstruction [START_REF] Serna | Extracorporeal septoplasty: variations of the technique[END_REF]. Extracorporeal septorhinoplasty with external septal cartilage remodeling and its reinsertion within the mucoperichondrial pocket represents an alternative to deal with these issues and to enhance good functional and aesthetic results [START_REF] Baser | The Role of Extracorporeal Septoplasty in Severely Deviated Nasal Septum[END_REF]. In our practice, this technique is particularly interesting for severe anterior and superior septal deviation, but also for severe caudal septal deviation with the development of the anterior septal reconstruction alternative.

The current concept of extracorporeal septorhinoplasty consists of « en bloc » removal of the bony-cartilaginous septal partition, extracorporeal creation of a straight and firm neoseptum (L-strut), and reimplantation by fixation to both bony and cartilaginous framework. The whole procedure is performed as part of a septorhinoplasty using an open approach that is surely more adequate and surgeon friendly [START_REF] Gubisch | Twenty-five years experience with extracorporeal septoplasty[END_REF][START_REF] Rezaeian | New Suturing Techniques to Reconstruct the Keystone Area in Extracorporeal Septoplasty[END_REF]. Although possible, secure fixation of the neoseptum on the keystone area and internal nasal valve grafting are significantly more difficult and risky with a closed approach [START_REF] Marangi | Functional Results of a Modified Extracorporeal Septoplasty With Open Access[END_REF].

The ideal reconstructed septum would be as large as possible with stable upper and anterior borders [START_REF] Gubisch | Twenty-five years experience with extracorporeal septoplasty[END_REF]. Recommended minimum dimensions of the neoseptum L-strut are 30-35 mm at the dorsal end and 20-25 mm at the caudal border [START_REF] Serna | Extracorporeal septoplasty: variations of the technique[END_REF]. If only small pieces of cartilage are available and a large straight perpendicular plate of the ethmoid bone is present, this plate can be used as a scaffold to support small pieces of conjoined cartilage [START_REF] Cerkes | The crooked nose: principles of treatment[END_REF]. Bone alone is not an optimal graft for the septum L-strut due to its tendency to be resorbed. Some authors recommend the use of an artificial material such as PDS foil, which seems to act as a scaffold and a guide for cartilage regeneration [START_REF] Rimmer | Use of polydioxanone plate in septal reconstruction[END_REF]. However, this biomaterial device presents a risk of foreign body reaction especially to an already traumatized nose. A preferential approach is the use of rib cartilage harvesting that is plannified prior to surgery, with the help of a CT scan, in case of absence of sufficient septal donor tissue. The key point to avoid warping of rib cartilage is by sectioning the rib at the beginning of the operation, hydrating the sectioned cartilage, and using only its core sections for straight grafts. Conchal cartilage is the choice if nonstructural grafts are needed, such as for supratip, nasion, or lateral nasal wall camouflage grafts but is surely not a reliable material for structural grafting [START_REF] Serna | Extracorporeal septoplasty: variations of the technique[END_REF].

The most critical point in extracorporeal septorhinoplasty is reimplantation of the neoseptum. This requires reattachment of both the cephalic dorsal neoseptum and the caudal part to the anterior nasal spine. To reattach the cephalic dorsal neoseptum to the bonycartilaginous transition zone, two surgical techniques are mainly used: classical U-shaped sutures to the upper lateral cartilages and the « criss-cross » suture technique (Please insert Figures 5A and5B). Gubisch et al. also described the transcutaneous transosseous cerclage suture, performed in a percutaneous fashion and very interesting especially when the nasal bones are too short to permit the « criss-cross » suture. Both techniques aim at stable and strong refixation of the neoseptum at the bony-cartilaginous transition zone and to avoid complications such as saddling nose [START_REF] Rezaeian | New Suturing Techniques to Reconstruct the Keystone Area in Extracorporeal Septoplasty[END_REF]. We think, therefore, that « criss-cross » or transcutaneous cerclage sutures are mandatory when lateral nasal bones osteotomies are performed adding instability to the nasal framework. However, when osteotomies are not realized, fixation to the upper lateral cartilages may be sufficient, also allowing easy positioning of spreader grafts to treat nasal valve insufficiency. When just a caudal without middle third dorsal deviation of the septum is observed, it is much more adapted to perform an anterior septal reconstruction (ASR) that may be a good alternative minimizing destabilization of the keystone area. Thus, ASR is sutured to the upper lateral cartilages or to the remaining non-deviated septal cartilage and appears a more conservative technique than extracorporeal septorhinoplasty [START_REF] Most | Anterior septal reconstruction: outcomes after a modified extracorporeal septoplasty technique[END_REF][START_REF] Moubayed | Correcting Deviations of the Lower Third of the Nose[END_REF][START_REF] Toriumi | Subtotal septal reconstruction: an update[END_REF] (Please insert Figure 5C). Furthermore, to avoid possible irregularities of the nasal dorsum following extracorporeal septorhinoplasty, camouflage techniques can be used as suggested above. One of our favorite, and most of the time sufficient, is to suture on the median line the two upper cartilages perichondrial flaps dissected previously. With the use of this technique and a strong fixation of the neoseptum, complications and imperfect results can be avoided.

Fixation of the neoseptum caudal border to the anterior nasal spine was originally performed by passing a stitch through the cartilage and then through a hole drilled into the bone with a burr. After a few cases, the suture of the reconstructed septum was performed directly through the periosteum of the anterior nasal spine without differences in longterm outcomes [START_REF] Serna | Extracorporeal septoplasty: variations of the technique[END_REF].

As a conclusion, anterior and/or superior complex septal deviations may not be adequately addressed through standard septoplasty techniques; and it appears that extracorporeal septorhinoplasty by open approach is an alternative but effective procedure that can correct a severely twisted nasal septum (Please insert Figure 6). Reconstruction of the septum will sometimes require the use of the ethmoid perpendicular plate or extranasal cartilage grafting or exceptionally biomaterial (PDS) [START_REF] Mcgrath | Review and update on extracorporeal septoplasty[END_REF]. Secure fixation of the neoseptum

Figure captions - 1 .-Figure 2 .-Figure 3 .Figure 4 .-Figure 6 .

 captions12346 Figure captions

Disclosure of interest

The authors declare that they have no competing interest.


Muller

Giroux-Metges Ma

Dupré Pf

How to promote physical activity during pregnancy : A systematic review

Keywords:

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Physical activity during pregnancy has been shown to have a number of benefits : reduced risk of gestational hypertension, gestational diabetes mellitus, lower back pain, caesarean delivery and levels the chances of a normal uncomplicated delivery [START_REF] Yu | Effect of exercise during pregnancy to prevent gestational diabetes mellitus: a systematic review and meta-analysis[END_REF][START_REF] Magro-Malosso | Exercise during pregnancy and risk of gestational hypertensive disorders: a systematic review and meta-analysis[END_REF][START_REF] Wang | A randomized clinical trial of exercise during pregnancy to prevent gestational diabetes mellitus and improve pregnancy outcome in overweight and obese pregnant women -American Journal of Obstetrics & Gynecology[END_REF][START_REF] Shiri | Exercise for the Prevention of Low Back Pain: Systematic Review and Meta-Analysis of Controlled Trials[END_REF][START_REF] Poyatos-León | Effects of exercise during pregnancy on mode of delivery: a meta-analysis[END_REF][START_REF] Tinloy | Exercise during pregnancy and risk of late preterm birth, cesarean delivery, and hospitalizations[END_REF][START_REF] Magro-Malosso | Exercise during pregnancy and risk of preterm birth in overweight and obese women: a systematic review and meta-analysis of randomized controlled trials[END_REF]. International guidelines recommend at least 150 minutes of physical activity (PA) per week [START_REF] Has | Prescription d'activité physique et sportive pendant la grossesse et en postpartum[END_REF][START_REF] Davenport | Canadian Guideline for Physical Activity Throughout Pregnancy: Methodology[END_REF][START_REF] Artal | Guidelines of the American College of Obstetricians and Gynecologists for exercise during pregnancy and the postpartum period[END_REF][START_REF]Activité physique et sportive et grossesse et état post partum[END_REF][START_REF] Bø | Exercise and pregnancy in recreational and elite athletes: 2016 evidence summary from the IOC expert group meeting, Lausanne. Part 1-exercise in women planning pregnancy and those who are pregnant[END_REF].

Currently, pregnant women spend more than 50% of their time living a sedentary lifestyle [START_REF] Fazzi | Sedentary behaviours during pregnancy: a systematic review[END_REF]. Physical activity decreases drastically from pregnancy diagnosis to 3 months postpartum [START_REF] Fell | The Impact of Pregnancy on Physical Activity Level[END_REF][START_REF] Lindqvist | Change of lifestyle habits -Motivation and ability reported by pregnant women in northern Sweden[END_REF][START_REF] Schmidt | Physical Exercise During Pregnancy -How Active Are Pregnant Women in Germany and How Well Informed?[END_REF]. Up to 58% of women do not achieve the recommended amount of activity to be considered physically active during pregnancy [START_REF] Leavitt | Physical Activity Guidelines for Americans[END_REF]. Pregnancy remains an ideal time to encourage a healthy lifestyle where pregnant women are more receptive to health messages [START_REF] Lindqvist | Change of lifestyle habits -Motivation and ability reported by pregnant women in northern Sweden[END_REF]. Health professionals should focus on setting up interventions to promote physical activity during pregnancy. However, 83% of medical practitioners are not aware of these recommendations [START_REF] Watson | Exercise during pregnancy: knowledge and beliefs of medical practitioners in South Africa: a survey study[END_REF]. Furthermore, behavioural interventions are time-consuming and resource-consuming and their accessibility can be limited [START_REF] Wurz | Breast cancer survivors' barriers and motives for participating in a group-based physical activity program offered in the community[END_REF]. In a systematic review published in 2013 of randomized controlled trials that measured the efficacy of a PA intervention targeted at pregnant women, only three out of nine interventions reported statistically and clinically significant results for increasing PA [START_REF] Pearce | Strategies to Promote Physical Activity During Pregnancy[END_REF]. The aim of this study was to conduct a recent systematic review of literature on the efficacy of interventions to improve PA among pregnant women.

Trials were included if they were written in the English language. A systematic review was conducted and included randomized controlled trials (RCT) that measured the efficacy of an intervention designed to promote physical activity during pregnancy. The impact of the intervention on PA could be a primary or secondary endpoint. Studies that were not RCTs and/or were specifically designed for women in the post-partum period were excluded.

Studies that evaluated a level of physical performance to be attained were also excluded because the objective of this review was to study strategies, methods and means to increase PA during pregnancy. Studies in which several methods of promotion of PA were compared without a control group were also excluded.

Article selection process

The Pubmed/Medline database was consulted in December 2017 and references extracted from bibliographies were also studied and added manually. The research was carried out using the following MeSH keywords: "PREGNANCY" and "EXERCISE", crossed with the Boolean operator "AND". Articles published between January 2008 to September 2019 were selected. A systematic literature review was conducted following the four steps according to PRISMA Statement recommendations. A cross-reading was carried out by two reviewers. Data extracted from each article was presented to the co-authors and group discussion led to the selection of the most relevant information.

Data extraction

Ten components were extracted from each article using a data abstraction form modelled after the "Guide to Community Preventive Services: Systematic Reviews and Evidence-Based Recommendations" developed by the Task Force on Community Preventive Services [START_REF] Zaza | Data collection instrument and procedure for systematic reviews in the guide to community preventive services11The names and affiliations of the Task Force members are listed on page v of this supplement and at http://www.thecommunityguide.org[END_REF]. Abstracts were reviewed and relevant articles were obtained in full text. They were then analysed and data was extracted and entered in an Excel table (Microsoft Excel version 2016). Each abstract and full-text article was analysed by two examiners. General elements gathered in each article were the year of publication, country of origin of data, sample characteristics, number of patients, description of the trial, type of intervention, primary endpoint, secondary endpoint, physical activity assessment method, and conclusion.

Population characteristics

Population characteristics were extracted and included information on sample size, country, age, population demographics, socioeconomic status, parity and the context of the pregnancy (normal pregnancy, high-risk pregnancy).

Study characteristics

Study characteristics included an assessment of whether physical activity was the primary or secondary endpoint and how this endpoint was evaluated : self-administered questionnaires or objective pedometer or accelerometer measurements.

Intervention strategy characteristics

The characteristics of the intervention strategies include a general description of the

Methodological characteristics

Based on Pearce et al.'s methodology [START_REF] Pearce | Strategies to Promote Physical Activity During Pregnancy[END_REF], the characteristics we extracted from the trials included information on trial design, power analysis, measurement of PA and other outcomes, data collection schedule, statistical analyses, and process evaluation. Presence of a power analysis was coded as either yes or no, measurement of PA was coded as one or more of the following: self-administered questionnaire, laboratory test, record review, attendance, and other, and was also assessed qualitatively. The data collection schedule was assessed qualitatively.

Outcome data

The aim was to evaluate methods used to promote physical activity during pregnancy. The main outcome was the increase of PA. The majority of outcome information was coded to indicate presence or absence and then described qualitatively to assess possible threats to validity. We considered an intervention to have an effect if there was a statistically significant (p< 0.05) difference between intervention and control groups.

Results

In total, 257 articles were extracted from PUBMED with the selected keywords.

Overall, 202 articles didn't meet inclusion criteria. Fifty-five articles were selected in full text, 3 articles were added by manual search. Finally, 15 articles published between 2008 and 2019 were included in the study. Given the qualitative nature of most articles, the quality of articles selected by the Jadad scale was uninformative and therefore was not presented.

The results are presented in Table 1.

Population characteristics :

A total of 5633 patients were included among these fifteen trials. Five trials were carried out on an American population [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Guelinckx | Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial[END_REF][START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF], four among Australian women [START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF], three among Finnish women [START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF], one among Irish women [START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF], one among Chinese women [START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF] and one among Canadian women [START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF].

One trial was performed on a population of pregnant women who were diagnosed with gestational diabetes mellitus [START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF] and three trials were conducted on a population at risk of developing gestational diabetes mellitus [START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF].

Four trials were carried out on a population of women with a body mass index (BMI) greater than 25kg/m 2 [START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF], one trial was performed on a population of pregnant women with a BMI greater than 29 kg/m 2 (27) and six trials were carried out on a population of pregnant women with no complications [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF].

Study characteristics :

Seven trials rated physical activity as the primary outcome [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF], eight trials rated PA as a secondary endpoint [START_REF] Guelinckx | Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF]. Twelve of the fifteen trials analysed PA by self-administered questionnaires [START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Guelinckx | Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial[END_REF][START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF], three trials used objective methods such as pedometer or accelerometer measurements [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF].

All trials randomized participants in at least two groups, case groups and control groups. Control groups received treatment according to conventional pregnancy care. Two of the trials had two case groups [START_REF] Guelinckx | Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF], to compare an additional intervention with the initial intervention which was studied.

Interventions strategies and techniques

Seven of the trials [START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF] suggested promoting physical activity through individual interviews. These interviews consisted of informing the patients about the risks of a sedentary lifestyle and physical inactivity, information about minimal physical activity required for pregnant women, and often information about nutrition and risks related to an unbalanced diet. This information could be given during individual interviews, face-to-face interviews or multiple interviews during pregnancy [START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF], and could be reinforced by short interventions such as telephone interviews [START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF], mailing lists [START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF] or during routine consultations [START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF].

Three trials evaluated interventions based on group interviews [START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Guelinckx | Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF]. At least one group interview was necessary during pregnancy [START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF] and the discussion could be completed by either informative brochures [START_REF] Guelinckx | Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial[END_REF] or by a treadmill available for use [START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF].

Two trials [START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF] were focused on the evaluation of multimedia interventional support, with an educational DVD [START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF] or an interactive video [START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF]. One trial evaluated a brochure [START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF]. Finally, two trials evaluated the utility of a Smartphone application to promote physical activity [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF].

The majority of the interviews were conducted as individual interviews [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF]. Two trials conducted the intervention in group interviews [START_REF] Guelinckx | Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF] and one study combined individual and group interviews [START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF]. In most trials, intervews were repeated during pregancy [START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF]. Only four trials carried out a one-time interview [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF].

Twelve trials focused their strategies on behavioural interventions [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF]) and 3 on environmental interventions [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF]. For 13 of the 15 selected trials, intervention messages were delivered during a clinical interview [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Guelinckx | Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF]. Only Jackson et al. and Prapavessis et al. did not carry out a clinical interview [START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF]. Seven trials involved a lowrisk population [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF], 7 trials involved a high-risk population [START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Guelinckx | Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF] and one trial involved both low-risk and high-risk populations [START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF].

Qualitative information, according to the Gardner et al. [START_REF] Gardner | Changing diet and physical activity to reduce gestational weight gain: a meta-analysis: Nutrition and activity in pregnancy[END_REF] and Michie et al. [START_REF] Michie | The behaviour change wheel: A new method for characterising and designing behaviour change interventions[END_REF] classifications, was distributed as follows (a trial could use different techniques) : 14 trials used information techniques [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Guelinckx | Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial[END_REF][START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF], 9 used instruction techniques [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF], 4 used feedback techniques [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF], 9 used problem-solving techniques [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Luoto | Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial[END_REF], none used reward techniques, 8 used self-monitoring techniques [START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF], 11 used goal-setting techniques [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF][START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Szmeja | Use of a DVD to provide dietary and lifestyle information to pregnant women who are overweight or obese: a nested randomised trial[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF][START_REF] Aittasalo | Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland[END_REF][START_REF] Aittasalo | Physical activity counseling in maternity and child health care -a controlled trial[END_REF][START_REF] Currie | Application of objective physical activity measurement in an antenatal physical activity consultation intervention: a randomised controlled trial[END_REF][START_REF] Chan | Randomized trial examining effectiveness of lifestyle intervention in reducing gestational diabetes in high risk Chinese pregnant women in Hong Kong[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF], and one trial used a modeling technique [START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF].

Overall effectiveness

Among the fifteen trials included in this review, five reported a statistically significant increase in PA between the intervention group and the control group in favor of the intervention group [START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF][START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF][START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF][START_REF] Wilkinson | Evaluation of the "healthy start to pregnancy" early antenatal health promotion workshop: a randomized controlled trial[END_REF][START_REF] Gaston | Maternal-fetal disease information as a source of exercise motivation during pregnancy[END_REF]. All five trials reporting a significantly effective intervention conducted at least one individual interview. Overall effectiveness is represented in Figure 2.

Discussion

We carried out this review of literature aiming to demonstrate evidence of effective interventions to promote physical activity during pregnancy. We analysed 15 trials in total, of which five showed significant results. Overall these results are questionable by the methodology which was used, by the difficulty of obtaining an objective assessment of physical activity, and by the small size of the sample in each study. We mainly encountered four types of interventions to promote PA during pregnancy: individual interviews, group interviews, access to information via brochures or multimedia supports, and more recently the use of Smartphone applications for personal training and general information.

Individual interventions were the most common interventions and were often

reinforced by reminders during routine consultations, or through emails or informative brochures. Chasan-Taber et al. [START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF] showed that an initial intervention, combined with regular reminders through emails and phone calls, reduced the decline of PA during pregnancy in a population of women at risk of developing gestational diabetes. PA was evaluated as a primary endpoint by a validated self-administered questionnaire during pregnancy, the "PPAQ". The fact that PA was evaluated as a primary outcome by a questionnaire known to be officially validated in a population of pregnant women brings value to this study, as does the size of the population (n>100). Nevertheless, we can point out that this type of intervention, which is relatively "intensive", such as email reminders once or twice per week and regular telephone calls, showed only a small reduction of PA decline during pregnancy. Dodd et al. [START_REF] Dodd | The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial[END_REF], reported the same trend from their study in overweight or obese pregnant patients. The impact of an individual intervention associated with 2 reminders via telephone allowed an increase in PA in these patients. PA was assessed here by a questionnaire "SQUASH" (39) which had not been officially validated during pregnancy. PA was evaluated as a secondary endpoint which limits the outcome of this study.

Concerning group interventions, Prapavessis et al. (38) evaluated a group

intervention associated with available information leaflets about balanced diets and physical activity during pregnancy. They reported an increase in PA in the group that benefited from the intervention. PA was evaluated as a secondary endpoint by a self-administered questionnaire (GLTEQ) which hadn't been validated in pregnant women. The methodology used to evaluate PA limits the outcome of the study, therefore these results should more likely be interpreted as a trend.

Kong et al. [START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF] carried out an unusual study. Treadmills were available to the patients, after a group meeting explaining the benefits of PA during pregnancy. Their results reported a significant increase in PA, which was measured objectively by pedometers.

Unfortunately, the primary endpoint was not unique and the population size was small (n = 37), which could make interpretation difficult.

Studies evaluating multimedia supports, such as interactive videos, carried out by Jackson et al. [START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF], showed an increase in PA with this device. These results are also to be taken with hindsight, since PA was evaluated as a secondary endpoint using questions from a questionnaire dedicated to health assessment.

Concerning PA promotion interventions using "connected" devices, Choi et al. [START_REF] Choi | mHealth Physical Activity Intervention: A Randomized Pilot Study in Physically Inactive Pregnant Women[END_REF] evaluated a Smartphone application to promote PA in a population of women with a physiological pregnancy. Results did not show a significant difference between the 2 groups, but the study was presented as a feasibility study and did not have sufficient power to conclude. It is possible that this study did not highlight a difference that actually existed. Dodd et al. [START_REF] Dodd | Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial[END_REF] recently assessed the interest of a Smartphone application in promoting a healthy lifestyle during pregnancy. They concluded that there was no significant result, but they had evaluated PA as a secondary endpoint which suggests that these results are, again, to be interpreted as a trend.

The weaknesses of this review are numerous. The different methodologies and intervention strategies make the comparison between studies difficult. The populations studied are different between trials, some involved low-risk pregnancies, others involved high-risk pregnancies. The primary endpoint that we chose for our review, that is physical activity, was a secondary endpoint in only 6 of the 15 trials. This work has also revealed that in the majority of the 15 trials, PA was assessed with declarative questionnaires. However, several studies revealed limitations to these self-administered questionnaires which do not accurately reflect the amount of PA, showing significant variations, and often suggests a much smaller amount of PA compared to what was declared [START_REF]4ème baromètre Assureurs Prévention sur le niveau d'activité physique ou sportive de la population française | Épisanté Bourgogne[END_REF]41). Harrison et al. showed that compared to the accelerometer, the pedometer gives a reliable estimate of physical activity during pregnancy, whereas the International Physical Activity Questionnaire (IPAQ) is less accurate in this context [START_REF] Harrison | Measuring physical activity during pregnancy[END_REF]. The use of accelerometers is the best tool for evaluating physical activity [START_REF]4ème baromètre Assureurs Prévention sur le niveau d'activité physique ou sportive de la population française | Épisanté Bourgogne[END_REF][START_REF]Activités physiques et santé[END_REF], and the automatic incorporation of these devices into all new communication tools, such as Smartphones, should encourage employment of these tools.

Finally, some studies that have shown that coaching has an impact on the increase in PA is based on small sample sizes, such as Kong et al.'s trial [START_REF] Kong | A Pilot Walking Program Promotes Moderate-Intensity Physical Activity during Pregnancy[END_REF].

Concerning the strengths of this review, we have noted a tendency to promote PA for pregnant women during individual or group interventions, often associated with regular information during pregnancy. Intervening early during pregnancy can encourage women to become aware of their physical inactivity and sedentary lifestyle, and thereby question health professionals more easily on which strategy to put into place to improve their level of activity.

The ideal intervention probably does not exist, but the optimal intervention presumably depends on a combination of these different types of interventions.

Smartphones, are interesting features, because of their very wide accessibility to young women, the current interest that these new technologies create and their capacity to record objectively a number of steps by incorporated accelerometers. Nevertheless, these tools, if they remain isolated or inaccurately adapted to pregnant women, will most likely be ineffective. These tools must be integrated into a genuine care program with a justified medical prescription from the healthcare professional who will perform the follow up and give out regular information. Smartphone applications developed for this purpose, with regular encouragements to begin PA, relaxation and stretching exercises, would allow the broadcasting of regular information which, as we have seen above, seems to be favourable to the promotion of PA [START_REF] Chasan-Taber | Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study[END_REF]. Regular individual pregnancy monitoring, as well as collective childbirth classes, could be used to give out information about PA and its importance during pregnancy. Midwives have the skills and ability to establish a trusting relationship with patients, and seem to be the best healthcare providers to give out this information. The development of an official video platform about promotion of physical activity by midwives, similar to the study by Jackson et al. [START_REF] Jackson | Improving diet and exercise in pregnancy with Video Doctor counseling: A randomized trial[END_REF], also seems to be an interesting idea to exploit.

Conclusion

Physical activity during pregnancy reduces obstetric comorbidity. Despite this, many pregnant women do not achieve sufficient physical activity, as advised by official recommendations, and even decrease their level of activity during pregnancy. Some healthcare professionals are currently trying to carry out interventions for pregnant women to promote PA during pregnancy. The objective of our review was to evaluate different intervention strategies to increase PA during pregnancy. Our systematic review of literature did not allow us to compare the different interventions between them because of an important variability of interventions and methodology used. Overall, the trends show that these interventions have a small impact on the promotion of PA during pregnancy. In addition, there does not appear to be one single technique that has an impact on PA increase, but a combination of different strategies could help to achieve this goal. The use of mHealth, and in particular of smartphone applications specifically developed for pregnant women, could thanks to its technology and simplicity, allow this objective to be achieved and evaluated.

Figures and tables :

  intervention techniques designed to influence behavior. The different types of interventions have been classified as follows: individual interview, group interview, one-time information, repeated information, behavioral intervention, environmental intervention, clinical high risk target population and general target population. Similar to Pearce et al. (20), we used the classifications of Gardner et al. and Michie et al. (22,23) to describe qualitative information about the techniques used : information, instruction, feedback, problem-solving, reward, selfmonitoring, goal-setting, and modeling.

Figure 1 :

 1 Figure 1: Effective and ineffective intervention techniques. Intervention techniques were considered effective if the study reported a statistically significant (p<0,05) difference between intervention and control groups.

Table 1 : interventions included in review, n = 15

 1

	Reference	Sample characteristics PA measure	Theory	Intervention summary	Findings
	Aittasalo et al. (33) Year of publication : 2012 Intervention target : Gestational diabetes. Mellitus (GDM), Leisure time physical activty (LTPA) Country : Finland	n = 442 Population : Pregnant women at risk for gestational diabetes mellitus Intervention group : n = 219 Age : 24-34 Race : not reported BMI : 21,4-31,2 BMI ≥ 25 (%) : not reported	LTPA***** ( PA in minutes per week)	Model introduced by Laitakari and Asikainen (44): Logical sequence of work steps for health care purposes, personal aspects, maintenance. strategies for concepts and educational determinants of PA, stage of adoption,	duration (4 to 13 mins). All participants at the first maternal visit but of short conventional care including PA counseling meeting. Control group received telephone counseling 1 week after each each meeting. Participants received Description : Intervention group assisted to 5 PA counseling sessions where they were given a counseling manual and a take-home leaflet. Participants were offered an opportunity to attend to 5 different monthly group meetings of PA. Participants were reminded by a SMS 1 week prior to	No significant difference between intervention and control groups
		Control group : n = 180 Age : 25 -34 Race : not reported BMI : 22,1-30,7 BMI ≥ 25 (%) : not reported			received self-administered baseline LTPA questionnaire at 8-12 weeks' gestation and 2 follow up questionnaires at 26-28 and 36-37 weeks' gestation. Recommended PA : 800 MET minutes per week Setting : maternity clinics
					Delivered by : nurses, physiotherapists
					Number of sessions : 5 counseling sessions, 5
					PA meetings
					Duration of sessions : 20-30 mins for primary
					sessions and 10-15 mins for the booster
					sessions, 2h for PA meetings
					Duration of intervention : 6 months
	Aittasalo et al. (34) Year of publication : 2008 Intervention target : effects and feasibility of individual PA counseling Country : Finland	n = 132 Population : Pregnant women and post partum women with no earlier deliveries Intervention group : n = 69 Age : 22-32 Race : not reported BMI : 20,2-28 BMI ≥ 25 (%) : 31 BMI ≥ 25 (%) : 18 BMI : 20,4-25 Race : not reported Age : 24-32 n = 63 Control group :	LTPA***** (Number of days per week of LTPA, minutes of LTPA per week) IPAQ***	Model introduced by Laitakari and Asikainen (44): Logical sequence of work steps for health care purposes, personal aspects, maintenance. strategies for concepts and educational determinants of PA, stage of adoption,	was 20-30 minutes and for each of the Duration of sessions : primary counseling Number of sessions : 5 Delivered by : nurses care clinics, home Setting : maternity clinics and child health Recommended PA : 800 MET minutes postpartum in child health clinics. maternity clinics and 5 and 10 months at 16-18 and 36-37 weeks' gestation in was elicited by questionnaire and followed Description : In the intervention group, participants received primary and four booster PA counseling sessions. An option for supervised group exercise was offered. In control group former practices, usually including brief PA advice, were continued. Leisure-time PA (LTPA) prior to pregnancy	No significant difference between intervention and control groups
					boosters 10-15 minutes.
					Duration of intervention : 8 months

Table 1 : interventions included in review, n = 15

 1

	Reference	Sample characteristics PA measure	Theory	Intervention summary	Findings
	Chan et al. (37) Year of publication : 2018 Intervention target : improving GDM, maternal and infant outcomes, gestational Country : China weight gain	(kg/m2) : 23.4 ± 3.9 Pre-pregnant BMI Race : not reported Age : 33.1 ± 4.1 n = 86 Control group : n = 220 Population : Pregnant women at risk for GDM Intervention group : n = 80 Age : 33.2 ± 4.4 (kg/m2) : 22.6 ± 3.8 Pre-pregnant BMI Race : not reported	Chinese version of the International Physical Activity Questionnaire (IPAQ-C)	The intervention was designed based on a clinically proven lifestyle modification program (LMP)	Setting : maternity clinic/home exercise at least three times a week moderate intensity low impact aerobic Recommended PA : 30 minutes of easy to received routine antenatal care. individualized diet plan. Control group gestation). Each participant was given an the intervention (i.e. 24-28 weeks of face consultations afterwards till the end of Description : In the intervention group LMP group participants completed a dietitian-led LMP including dietary and exercise components from early pregnancy till 24-week gestation. Participants received bi-weekly face-to-face or phone consultations in the first 2 months and monthly face-to-	No significant difference between intervention and control groups
					Delivered by : dietitian and exercise
					instructor
					Number of sessions : 20
					Duration of sessions : 1h for the first face-
					to-face session, and 20mins for the follow-
					up consultations through face-face
					interviews or phone calls
					Duration of intervention : 8 months
	Chasan-Taber et al. (26) Year of publication : 2011 Intervention target : feasibility and preliminary efficacy of an exercise intervention, GDM Country : USA	n = 110 Population : Pregnant women at risk for GDM Intervention group : n = 58 Age (years): 16-40 Race : Non-hispanic white : 44.4%; Hispanic : 55.6% BMI (kg/m2) : < 18,5 : 0% 18,5-25 : 3.4% Above 30 : 62.1% 25-30 : 34.5%	"PPAQ****" : average weekly energy expenditure (MET-hrs/wk)	Transtheoretical model and social cognitive theory	the participant received, via mail, weekly Description : Intervention group participants received a face-to-face session to provide individual counseling. During follow-up, mailed, print-based materials and telephone booster calls provide motivationally-based individualized feedback were carried out. Intervention materials were mailed weekly for the first 4 weeks of the intervention, and then biweekly for the last 8 weeks of the intervention. Patients were given a brochure for specificities of PA during pregnancy. Following the face-to-face visit,	The intervention arm experienced a smaller decrease in total physical activity as compared with the control arm (p = 0.03)
					and biweekly follow-up tailoring
		Control group : n = 52 Age (years): 16-40 Race : Non-hispanic white : 34.7%; Hispanic : 65.3% BMI (kg/m2): < 18,5 : 0% 18,5-25 : 0% 25-30 : 47.1% Above 30 : 52.9%			questionnaires. In the control group participant received a face-to-face session reviewing general issues related to health and wellness during pregnancy. Participants received weekly and biweekly mailings of informational brochures and weekly and biweekly booster telephone calls. Recommended PA : 30 minutes or more of moderate-intensity activity on most days of the week Setting : home
					Delivered by : health educators
					Number of sessions : not reported
					Duration of sessions : 30 minutes of
					moderate intensity physical activity
					performed on 5 or more days per week
					Duration of intervention : 12 weeks

Table 1 : interventions included in review, n = 15

 1

	Reference	Sample characteristics PA measure	Theory	Intervention summary	Findings
	Choi et al. (24) Year of publication : 2016 Intervention target : feasibility and efficacy of mobile health (mHealth) intervention Country : USA	n = 30 Population : Pregnant women Intervention group : n = 15 Age (years): 32.9 ± 2.5 Race : Asian : 5%; Black : 1%; Hispanic/Latina : 2%; White : 7% Pre-pregnancy BMI (kg/m2) : 28.0 ± 3.7 (kg/m2) : 27.4 ± 3.9 Pre-pregnancy BMI 1%; White : 6% : 1%; Hispanic/Latina : Race : Asian : 7%; Black Age (years): 34.5 ± 2.5 n = 15 Control group :	Accelerometer (number of steps per week)	Social Cognitive Theory	with only the recommendations for received an initial brief in-person session, The control group (Fitbit Ultra only) also initial in-person session. support PA or to reinforce the topics of the own. Daily messages were prompts to encouraged to practice exercise on their Description : The Intervention group (mobile phone application and Fitbit Ultra) consisted in an mHealth intervention included daily messages and a mobile phone activity diary with automated feedback and self-monitoring systems. During a 30-min in-person session participants were given information about recommended PA (American College of Obstetricians and Gynecologists' guideline (ACOG)), recommendation for gestational weight gain and safety instructions and were	No significant difference between the 2 groups. This was a feasibility study with insufficient power to prove significant difference.
					gestational weight gain and safety
					instruction for promoting PA during
					pregnancy. Women in the control group
					were not given access to the trial app.
					Recommended PA : increase of steps by 10
					% each week until reach of at least 8500
					steps/day 5 days or more per week
					Setting : home
					Delivered by : not reported
					Number of sessions : not reported
					Duration of sessions : First in-person session
					: 30 mins
					Duration of intervention : 12 weeks
	Currie et al. (36) Year of publication : 2015 Intervention target : decline of PA during pregnancy Country : Ireland	n = 109 Population: low-risk pregnant women Intervention group : n = 47 Age (years): 31.7 ± 4.1 Race : not reported BMI (kg/m2) : 25.5 ± 3.3 Control group : n = 50 BMI (kg/m2) : 26.1 ± 4.9 Race : not reported Age (years): 30.55 ± 4.9	Daily PA was measured in each trimester using seven day accelerometry in counts per minute (CPM), which intensities. specific PA time spent in categorised into were then	Health Action Process Approach (HAPA)	intensity PA at least five times per week Recommended PA : 30 min of moderate hospital appointment. session, a PA consultation or a routine the researcher following the recruitment were provided with the accelerometer by standard antenatal care. All participants Description : Intervention participants received three face-to-face individual PA consultations. PA was objectively assessed at 12 to 15 weeks', 20 to 22 weeks' and 35 to 37 weeks' gestation, using an accelerometer. Women randomized to the control group received	No significant difference between intervention and control groups
					Setting : home/maternity clinic
					Delivered by : qualified researcher
					Number of sessions : 3
					Duration of sessions : 30 to 60 min
					Duration of intervention : 6 months

Table 1 : interventions included in review, n = 15

 1

	Reference	Sample characteristics PA measure	Theory	Intervention summary	Findings
	Dodd et al. (30) Year of publication : 2014 Intervention target : dietary intake and quality, maternal physical activity Country : Australia	n = 1924 Population : pregnant women with a BMI ≥25 kg/m2 Intervention group : n = 974 Age (years): 29.4 ± 5.4 Race : 90.7% caucasian BMI (kg/m2) : 25.0 to 29.9 : 42.1%; 30.0 to 34.9 : 29.0% ; 35.0 to 10.5% 39.9 18.5%; ≥40.0	"SQUASH*" questionnaire (MET-minutes per week)	Not reported	at 36 weeks'gestation. Women within the Description : Women were randomized to receive Lifestyle Advice or standard care. In the Lifestyle advice group, women participated in a dietary and lifestyle intervention over the course of their pregnancy, which included a combination of dietary, physical activity and behavioural strategies during a face-to-face session. This information was reinforced during subsequent inputs provided at 28 weeks' gestation and via telephone call at 22, 24, and 32 weeks'gestation and a face-face visit	Statistically significant increase in PA level in the intervention group compared with women receiving Standard Care.
					Lifestyle Advice group who had been
		Control group : n = 950 Age (years): 29.6 ± 5.4 Race : 91.2% caucasian BMI (kg/m2) : 25.0 to 29.9 : 44.3%; 30.0 to 34.9 : 28.2%; 35.0 to 39.9 : 16.3%; ≥40.0 : 11.2%			further randomized to the Walking group were invited to participate in a targeted, supervised walking group, in addition to receiving the information provided to all women assigned to the Lifestyle Advice group. Women randomized to receive Standard Care continued their pregnancy care according to local hospital guidelines, which did not include routine provision of
					advice related to diet, exercise, or
					gestational weight gain.
					Recommended PA : not recovered
					Setting : maternity hospital, home
					Delivered by : research dietician, trained
					research assistants, trained researcher
					Number of sessions : walking sessions three
					times per week,
					Duration of sessions : 40 minutes duration
					for walking sessions
					Duration of intervention : 10 months

Table 1 : interventions included in review, n = 15

 1

	Reference	Sample characteristics PA measure	Theory	Intervention summary	Findings
	Dodd et al. (32) Year of publication : 2017 Intervention target : dietary and physical activity change Country : Australia	n = 162 Population : Pregnant women Intervention group : n = 77 Age (years): 30.87 ± ≥40.0 6.5% 20% ; 35.0 to 39.9 7.5%; : 22%; 30.0 to 34.9 : 24.9 : 42%; 25.0 to 29.9 BMI (kg/m2) : 18.0 to Race : 72% caucasian 5.07	"SQUASH*" (MET minutes per week) questionnaire	Theories of health decision-making	telephone calls with the research assistant In addition, each woman received three weeks' gestation with a research assistant. dietitian and a face-to-face session at 36 attended two face-to-face sessions with a activity, and behavioural strategies. women involving a combination of dietary, physical Description : Participants were randomized to "Lifestyle Advice Only Group" or to the "Lifestyle Advice plus Smartphone ApplicationGroup". Women in the "Lifestyle Advice Only Group" received a comprehensive lifestyle intervention	No significant difference between intervention and control groups
		Control group : n = 85 Age (years): 31.01 ± 6.16 Race : 72% caucasian BMI (kg/m2) : 18.0 to 24.9 : 42%; 25.0 to 29.9 : 16%; 30.0 to 34.9 : 19%; 35.0 to 39.9 : 11%; ≥40.0 : 10.5%			at 22, 24, and 32 weeks' gestation to reinforce both the written information and the information provided in the face-to-face sessions. Women who were randomized to the Lifestyle Advice plus Smartphone Application Group received the same comprehensive lifestyle intervention and received access to a interactive smartphone application to reinforce information presented in both the
					face-to-face sessions and telephone calls.
					Recommended PA : not reported
					Setting : maternity hospital, home
					Delivered by : dietician, research assistants
					Number of sessions : 1 initial face to face
					session, and 1 session at 36 weeks'
					Duration of sessions : not reported
					Duration of intervention : 6 months
	Guelinckx et al. (27) Year of publication : 2010 Intervention target : physical activity, gestational weight gain Country : USA	n = 122 Population : obese white pregnant women with BMI superior to 29.0 kg/m2 Intervention group : n = 65 Age (years): not reported Race : caucasian BMI (kg/m2) : not reported Control group 1: n = 65 reported BMI (kg/m2) : not Race : caucasian reported Age (years): not	"BAECKE******" quesitionnaire	Not reported	Description : Participants were randomly assigned into 3 groups: a group that received nutritional advice from a brochure, a group that received the brochure and Duration of intervention : 6 months Duration of sessions : 1 hour Number of sessions : 3 Delivered by : nutritionist Setting : home/maternity clinic Recommended PA : not reported wk of pregnancy. which were scheduled at 15, 20, and 32 nutrtionist consisted of 3 group sessions control group. Lifestyle education by the lifestyle education by a nutritionist, and a	No significant difference between the 3 groups
		Control group 2 : n = 65 Age (years): not reported Race : caucasian BMI (kg/m2) : not reported

Table 1 : interventions included in review, n = 15 Reference Sample characteristics PA measure Theory Intervention summary Findings Luoto et al. (35)

 1

	Year of publication : 2011 Intervention target : GDM, newborns' birthweight, physical activity Country : Finland	n = 399 Population : pregnant women at high risk of GDM Intervention group : n=219 Age (years): 29.5 +/-4.8 Race : not reported Pre pregnancy BMI (kg/m2) : 26.3+/-4.9 Control group : n=180 Age (years): 30.0+/-4.7 Race : not reported Pre pregnancy BMI (kg/m2) : 26.4+/-4.3	LTPA***** (weekly MET minutes)	Model introduced by Laitakari and Asikainen (44)	Description : In the intervention groupe the primary physical activity counseling takes place at the first visit. The primary dietary counseling session is implemented during the visit at 16-18 Duration of intervention : 29 weeks meetings visit, 2 hours for monthly physical activity Duration of sessions : not reported for Number of sessions : 4 Delivered by : nurses, physiotherapists Setting : home/maternity clinics per week Recommended PA : 800 MET minutes or group exercise were arranged. extra counseling beyond usual practices clinics received routine care and no The women in the control maternity including group exercise. thematic meetings on physical activity opportunity to participate monthly the participants were offered an primary physical activity counseling visit four and diet at three visits. During the subsequent visits; physical activity at and dietary counseling are boosted at weeks' gestation. Both physical activity	No significant difference between the 2 groups
	Prapavessis et al. (38) Year of publication : 2009 Intervention target :exercise, maternal-fetal disease Country : Canada	n = 105 Population : pregnant women Intervention group : n=36 Age (years): 28 +/-5.07 Race : 77.8% caucasian, 22.2% other BMI (kg/m2) : not reported Attention control group : n=33 Age (years): 26.39+/-6.18 Race : 75.8% caucasian, 24.2% other BMI (kg/m2) : not reported Noncontact control group : n=36 Age (years): 27.31+/-reported BMI (kg/m2) : not caucasian, 22.2% other Race : 77.8% 5.87	"GLTEQ*******" questionnaire	Protection Motivation Theory (PMT)	Description : Participants were randomly assigned to one of three treatment conditions: PMT-present (experimental), PMT absent (attention control), or no information (noncontact control). Women in the PMT group read a brochure about the benefits of exercise during pregnancy incorporating the major components of PMT; perceived vulnerability (PV), Duration of intervention : 1 week Duration of sessions : not reported Number of sessions : not reported Delivered by : lead investigator Setting : home Recommended PA : not reported implementation intention (IMI). exercise, goal intention (GI), and toward maternal-fetal disease and completed measures of their beliefs Following treatment, all participants condition read a brochure about diet. Participants in the attention-control efficacy (RE), and self-efficacy (SE). perceived severity (PS), response	Significant difference between Intervention group and Control group (+8,6 MET-min/week (p<0,05))

Funding:

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Conflict of interest:

The authors report no conflict of interest.