Gestational weight gain and maternal immediate perinatal and postpartum outcomes in low and middle income countries: individual participant data meta-analyses

Objective: To estimate the associations between gestational weight gain and maternal immediate perinatal and postpartum outcomes by pooling data from low and middle income countries. Design: Individual participant data meta-analyses. Data sources: PubMed, Embase, Web of Science, and Cochrane Library, based on three searches (Search 1: all prospective studies published from January 2000 to May 2021; Search 2: randomized controlled trials of balanced energy and protein supplementation published until June 2021; Search 3: randomized controlled trials of anti-infectious agents published until August 2021). Eligibility criteria for selecting studies: Prospective studies (randomised controlled trials or observational cohort studies) with measured maternal weight during pregnancy and data available on maternal height, based in populations from low and middle income countries with no underlying conditions. Results: The analyses included 156 300 women from 61 studies and 23 countries, with most participants based in South Asia (n=78 454, 50.2%) and sub-Saharan Africa (n=36 327, 23.2%). Compared with women with adequate (90-125%) gestational weight gain, women with excessive (>125%) gestational weight gain had a higher risk of caesarean delivery (risk ratio 1.10, 95% confidence interval 1.06 to 1.13, τ²=0.000) and emergency caesarean delivery (risk ratio 1.22, 1.03 to 1.43, τ²=0.000). Women with moderately (70% to <90%) or severely inadequate (<70%) versus adequate gestational weight gain had lower risks for caesarean delivery (risk ratio in women with moderately inadequate gestational weight gain 0.88, 95% confidence interval 0.84 to 0.92, τ²=0.004; risk ratio in women with severely inadequate gestational weight gain 0.82, 0.77 to 0.88, τ²=0.010) and emergency caesarean delivery (risk ratio in moderately inadequate gestational weight gain 0.82, 0.71 to 0.95, τ²=0.004; risk ratio in severely inadequate gestational weight gain 0.73, 0.56 to 0.96, τ²=0.103). Excessive versus adequate gestational weight gain was associated with higher postpartum weight retained at any time point (mean difference 2.00 kg, 95% confidence interval 1.49 to 2.50, τ²=1.317), whereas moderately and severely inadequate gestational weight gain were associated with lower retained weight compared with adequate gestational weight gain. Similar trends were found for postpartum body mass index. Severely inadequate gestational weight gain was associated with lower systolic and diastolic blood pressure at any time point post partum than adequate gestational weight gain. No associations were observed for other outcomes including postpartum depressive symptoms or breastfeeding. Evidence indicating an interaction between gestational weight gain and body mass index before pregnancy was found when examining the risk of caesarean delivery and postpartum weight retention, body mass index, and systolic blood pressure as outcomes. Conclusions: These findings support the association between suboptimal gestational weight gain and adverse maternal outcomes in the immediate perinatal and postpartum periods. Further research examining the consequences of suboptimal gestational weight gain in low and middle income countries would be valuable to inform potential strategies to improve long term maternal health.