Pre-pregnancy BMI, gestational weight gain and postpartum weight retention: a meta-analysis of observational studies

Objective: To determine the association of gestational weight gain (GWG) or pre-pregnancy BMI with postpartum weight retention (PPWR). Design: Meta-analysis. Setting: PubMed, Cochrane Controlled Trials Register, EMBASE, Science Citation Index Expanded, Current Contents Connects and Biosis Previews were used to search articles. Subjects: Publications that described the influence of pre-pregnancy BMI or GWG on PPWR. Results: Seventeen studies that satisfied the eligibility criteria were included in the analyses. Women with inadequate and excessive GWG had significantly lower mean PPWR of -2.14 kg (95 % CI -2.43, -1.85 kg) and higher PPWR of 3.21 kg (95 % CI 2.79, 3.62 kg), respectively, than women with adequate GWG. When postpartum time spans were stratified into 1-3 months, 3-6 months, 6-12 months, 12-36 months and = 15 years, the association between inadequate GWG and PPWR faded over time and became insignificant (-1.42 kg; 95 % CI -3.08, 0.24 kg) after = 15 years. However, PPWR in women with excess GWG exhibited a U-shaped trend; that is, a decline during the early postpartum time span (year 1) and then an increase in the following period. Meta-analysis of qualitative studies showed a significant relationship between excessive GWG and higher PPWR risk (OR= 2.08; 95 % CI 1. 60, 2.70). Moreover, meta-analysis of pre-pregnancy BMI on PPWR indicated that mean PPWR decreased with increasing BMI group. Conclusions: These findings suggest that GWG, rather than pre-pregnancy BMI, determines the shorter-or longer-term PPWR.