Targeting the postpartum period to promote weight loss: a systematic review and meta-analysis.

CONTEXT: Many international clinical guidelines recommend that overweight and obese women lose weight prior to pregnancy to reduce the risk of adverse pregnancy outcomes. Women who have recently given birth and plan future pregnancies are an important target population for preconception weight-loss interventions.

OBJECTIVE: A systematic review to evaluate postpartum dietary and/or physical activity interventions to promote weight loss and improve health in a subsequent pregnancy was conducted.

DATA SOURCES: Five databases-the Cochrane Central Register of Controlled Trials, MEDLINE (through PubMed), Embase, the Australian New Zealand Clinical Trials Registry, and the International Clinical Trials Registry-were searched using the following terms: preconception, pregnancy, postpartum, pregnancy outcomes, body mass index, weight gain, weight loss, weight change, postpartum weight retention, dietary or lifestyle intervention, and randomiz(s)ed controlled trial. The date of last search was November 2017.

DATA EXTRACTION: Data were extracted from each identified study using a standard form. The primary outcomes were weight loss at the completion of the intervention and at follow-up assessments. Secondary endpoints included maternal and infant outcomes in a subsequent pregnancy.

DATA ANALYSIS: Mean differences (MDs) were calculated for continuous data and risk ratios for dichotomous data, both with 95%CIs.

RESULTS: A total of 235 abstracts (193 after duplicates were excluded) were identified, from which 37 manuscripts were selected for full-text review. In total, 27 trials were identified for inclusion. Outcome data were available for approximately 75% of participants (n = 3485). A combined dietary and physical activity intervention provided post partum produced greater postpartum weight loss (MD, -2.49 kg; 95%CI, -3.34 to -1.63 kg [random-effects model]; 12 studies, 1156 women), which was maintained at 12 months post partum (MD, -2.41 kg; 95%CI, -3.89 to -0.93 kg [random-effects model]; 4 studies, 405 women), compared with no intervention. No studies reported maternal or infant health outcomes in a subsequent pregnancy.

CONCLUSIONS: Providing a postpartum intervention is associated with weight loss after birth, but effects on maternal and infant health in a subsequent pregnancy are uncertain.