The effect of prenatal lifestyle intervention on weight retention 12 months postpartum: results of the N orwegian F it for D elivery randomised controlled trial

Objective To examine the effect of a prenatal lifestyle intervention on postpartum weight retention ( PPWR ). Design Randomised controlled trial. Setting Healthcare clinics in southern Norway. Population Healthy, nulliparous women with body mass index ≥19 kg/m 2 , age ≥18 years, and singleton pregnancy of ≤20 gestational weeks. Methods Women were randomised to intervention (dietary counselling twice by phone and access to twice‐weekly exercise groups during pregnancy) or control group (standard prenatal care). Intervention compliance was defined post‐factum as attending dietary counselling and ≥14 exercise classes. Main outcome measures PPWR (weight measured postpartum minus self‐reported pre‐pregnancy weight) and the proportion of women returning to pre‐pregnancy weight. Results Of 606 women randomised, 591 were included in an intention‐to‐treat analysis of pregnancy outcomes and 391 (64.5%) were analysed 12 months postpartum. Mean PPWR was not significantly different between groups (0.66 kg for intervention versus 1.42 kg for control group, mean difference −0.77 kg, 95% CI −1.81, 0.28; P  = 0.149). An increased proportion of intervention participants achieved pre‐pregnancy weight (53% versus 43%, OR 1.50, 95% CI 1.003, 1.471; P  = 0.045). However, the difference was not statistically significant when we adjusted for missing data (adjusted odds ratio ( OR ) 2.23, P  = 0.067) using logistic mixed‐effects models analysis. Women compliant with intervention had significantly lower PPWR than control participants, also after adjusting for potential confounders (adjusted mean diff −1.54 kg, 95% CI −3.02, −0.05; P  = 0.039). Conclusions The Norwegian Fit for Delivery intervention had little effect on PPWR , although women who were compliant with the intervention demonstrated significantly lower PPWR at 12 months. Tweetable abstract Norwegian Fit for Delivery RCT : little effect of lifestyle intervention on weight retention 1 year postpartum.