Impact of pre-pregnancy maternal body mass index on neonatal outcomes in twin delivery: A retrospective cohort study.

Objective: This study examined the potential link between maternal pre-pregnancy body mass index (PPBMI) with neonatal outcomes in twin pregnancies. Methods: This retrospective analysis records of 1,270 women with twin pregnancies, delivered at the Fujian Maternity and Child Health Hospital between 2019 and 2021, were retrospectively analysed. Women were diagnosed as underweight, normal BMI, and overweight/obese according to their PPBMI. Neonatal outcomes included low birth weight (LBW), intrauterine growth retardation (IUGR), prematurity, neonatal intensive care unit (NICU) admission, neonatal mortality, and low APGAR scores. Univariate and multivariable regression analyses were performed. Results: The proportions of neonates with LBW, IUGR, prematurity, and NICU admission were 34.7%, 2.5%, 27%, and 30%, respectively. Five neonatal deaths occurred, all born to mothers with normal BMI. Low APGAR scores at five minutes were observed in one neonate in the maternal overweight/obese group and one neonate in the normal maternal BMI group. Multivariate regression analysis showed that underweight women had an approximately twice higher risk of delivering LBW twins (OR 1.88, 95% CI: 1.26, 2.89) than women with normal BMI. No statistically significant associations were found between maternal BMI and other neonatal outcomes. Conclusion: Low PPBMI increases the risk of delivering LBW twins, independent of other factors. Our findings emphasize the importance of pre-pregnancy nutritional status in optimizing neonatal outcomes in twin deliveries.