Background Excessive weight gain during pregnancy is common in developed countries and increases the risk of complications during pregnancy, delivery and the postpartum period, which can affect both maternal and fetal outcome. Interventions to reduce excessive gestational weight gain have previously not been systematically evaluated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Objectives To determine whether published trials of interventions to reduce excessive gestational weight gain are of sufficient quality and provide sufficient data to enable evidence-based recommendations to be developed for clinical practice in antenatal care. Search strategy A literature search was conducted in the scientific databases PubMed, Cochrane Library, Cinhal and Pedro, and the reference lists of relevant articles were reviewed. The literature search was concluded on 15 August 2009. Selection criteria All randomised controlled trials (RCTs) were considered for inclusion. As the number of published RCTs was limited, we also considered for inclusion all nonrandomised intervention studies that included a control group. Systematic reviews were examined to identify additional original studies. Data collection and analysis Two reviewers independently assessed the quality of the methods and results of all included articles. Extracted data were classified using the GRADE system. Main results Four intervention studies with a randomised controlled design and four intervention trials with a nonrandomised controlled design met the inclusion criteria. As a consequence of important limitations in study design, inconsistency and lack of directness, the overall quality of evidence was judged to be very low using the GRADE system. Authors' conclusions The results of published intervention trials are of insufficient quality to enable evidence-based recommendations to be developed for clinical practice in antenatal care.

Objective: To evaluate if a feasible, low-cost intervention could decrease the percentage of women gaining weight above the Institute of Medicine (IOM) recommendations on gestational weight gain (GWG) compared with standard maternity care.

Design: A randomised controlled interventional design.

Setting: Antenatal clinics (n=14) in orebro county, Sweden, participated.

Population: Healthy women with a body mass index (BMI) 19kg/m(2), age 18years and adequate knowledge of Swedish language who signed in for maternity care at 16weeks of gestation.

Methods: Standard care was compared with a composite intervention consisting of education on recommended GWG according to IOM, application of personalised weight graph, formalised prescription of exercise and regular monitoring of GWG at every antenatal visit.

Outcome: The proportion of women gaining weight above IOM guidelines (1990) and mean GWG (kg) was compared between groups.

Results: In all, 445 women were randomised and 374 women remained for analysis after delivery. A majority of the women analysed were normal weight (72%). The intervention reduced the proportion of women who exceeded the IOM guidelines (41.1% versus 50.0%). The reduction was, however, not statistically significant (P=0.086). Mean GWG was significantly lower among women receiving the intervention, 14.2kg (SD 4.4) versus 15.3kg (SD 5.4) in the standard care group (P=0.029).

Conclusions: The low-cost intervention programme tested did significantly reduce the mean GWG but the proportion of women who exceeded the IOM recommendations for GWG was not significantly lower. ClinicalTrials.gov Id NCT00451425

Introduction: High weight retention after pregnancy is related to an increased risk of future obesity. The objective was to evaluate if an antenatal intervention, compared to standard care, could reduce postpartum weight retention (PPWR).

Material and methods: Women with body mass index >19, age ≥18 years, knowledge of Swedish, and pregnancy ≤16 weeks' gestation were randomized. Standard care was compared to a composite intervention including a personalized weight graph, education on recommended weight gain, prescription of exercise, and monitoring of weight until one year after delivery. Mean (kg) PPWR was compared between the groups and risk estimates (odds ratio) for excessive weight retention were calculated.

Results: Of 445 women randomized, 267 remained for analysis at ≤16 weeks postpartum and 168 at one year postpartum. The intervention group had a significantly lower mean PPWR at ≤16 weeks (1.81 kg (standard deviation, SD, 4.52) vs. 3.19 kg (SD 4.77), p=0.016). At one year postpartum, mean retention was still 0.7 kg lower in the intervention group (0.30 kg (SD 5.52) vs. 1.00 kg (SD 5.46)), the difference was not statistically significant (p=0.414). Gestational weight gain above Institute of Medicine recommendations was a significant risk factor for excessive weight retention (>5 kg) one year after delivery (OR 2.44; 95% CI; 1.08-5.52, p=0.029).

Conclusions: A composite lifestyle intervention during pregnancy reduced short-term weight retention, but the effect of the intervention did not remain at one year postpartum. A gestational weight gain above Institute of Medicine recommendations increases the risk of excessive long-term weight retention.