Interpregnancy Weight Gain and Risks of Perinatal Death: A Systematic Review and Meta-Analysis.

The link between interpregnancy weight gain (IPWG) and perinatal death remains unclear. This meta-analysis examines the impact of interpregnancy body mass index (BMI) increase on perinatal mortality. A comprehensive search was conducted in July 2024 across MEDLINE, Embase, Cochrane Library, and Web of Science. Observational studies quantitatively reporting IPWG and associated perinatal mortality outcomes were included. IPWG was defined as a weight gain of ≥ 2 BMI units or moving to a higher BMI category between consecutive pregnancies. The risk of bias was assessed using the ROBINS-I tool. Random effects meta-analyses were performed to generate pooled adjusted odds ratios (aORs) and 95% confidence intervals (CIs). The analysis included 10 studies (3,072,698 pregnancies). The primary outcome was perinatal death (deaths occurring at ≥ 20 weeks of gestation up to 28 days postpartum). Secondary outcomes were stillbirth (intrauterine fetal death at ≥ 20 weeks) and neonatal death (deaths among live-born infants within 28 days of life). IPWG significantly increases the risk of perinatal death (aOR, 1.49; 95% CI, 1.32-1.69), stillbirth (aOR, 1.46; 95% CI, 1.23-1.72), and neonatal death (aOR, 1.39; 95% CI, 1.19-1.61), compared to stable interpregnancy weight. These findings suggest that IPWG may increase the risk of perinatal death, highlighting the importance of weight management counseling during the interpregnancy period.