Gestational weight gain (GWG) is associated with postpartum weight retention (PPWR) in women. However, the strength of the association between GWG and long-term PPWR and obesity and its public health burden and health policies are still unclear.
We have conducted three sets of analyses. Firstly, publications from different databases were systematically extracted and the articles relevant to this study were reviewed to quantify the effect estimate of GWG on PPWR and BMI using a bias-adjusted method. The Institute of Medicine categories of "inadequate," "adequate," and "excess" were used to define GWG. The time span for PPWR was divided into three periods (<1 year, 1 year to 9 years, and ≥15 years) to determine outcome at different times postpartum. Secondly, we have analyzed 27y PPWR data of the Mater-University of Queensland Study of Pregnancy (MUSP) cohort (N=2000) considering potential confounders and mediators. Finally, implications of the findings in recent health policy are critically examined.
Meta analyses of 12 studies showed that women with an inadequate GWG had a significantly lower mean PPWR of -2.14 kg (95%CI, -2.61 to -1.66) than women with an adequate GWG, who had a mean PPWR of 3.15 kg (95%CI, 2.47 to 3.82) up to 21 years postpartum. Over the postpartum time span, a U-shaped relationship was observed between the weighted mean difference calculated for women with excess GWG and the weighted mean difference calculated for women with adequate GWG, and this relationship was time independent between these two groups. MUSP 27y post-partum data showed that women who gained excess GWG they were at 4.5 times higher risk to become obese after 27 year post-partum compared to the women who gained adequate GWG. Implications of these findings in recent health policy changes will be discussed.
The findings of this study suggest that GWG outside of the Institute of Medicine recommendations can lead to both short-term and long-term postpartum weight imbalance.