Objective: To examine the association between interpregnancy weight change and the risk for adverse maternal and neonatal outcomes.
Methods: All live-born singleton births delivered at 21-42 weeks of gestation in women who had their first two consecutive births between 2009 and 2011 in Flanders (the northern part of Belgium) and who were included in the Study Center for Perinatal Epidemiology database (N=7,897) were included. Interpregnancy weight change was calculated as the difference between the prepregnancy body mass index (BMI) of the first pregnancy and the prepregnancy BMI of the second pregnancy. Multivariate logistic regression analysis to predict gestational diabetes mellitus, pregnancy-induced hypertension, cesarean delivery, macrosomia (4,000 g or greater), low birth weight (less than 2,500 g), and congenital malformations were performed.
Results: The adjusted odds ratio (OR) for gestational diabetes mellitus was 2.25 (95% confidence interval [CI] 1.33-3.78; P=.002) for interpregnancy weight retention of 2 or more BMI units, and the adjusted OR for pregnancy-induced hypertension was 3.76 (95% CI 2.16-6.57; P<.001) with an increase of 3 or more BMI units between pregnancies, but these associations were only present in underweight and normal-weight women. In overweight and obese women, the adjusted OR was 2.04 (95% CI 1.41-2.95; P<.001) for cesarean delivery for an interpregnancy weight retention of 2 or more BMI units. In underweight and normal-weight women, the risk for macrosomia was halved if women lost more than 1 BMI unit between pregnancies, but at the same time, the risk for low birth weight doubled.
Conclusion: We show that weight retention between the first and second pregnancy is associated with an increased risk for perinatal complications, even in underweight and normal-weight women. Stabilizing interpregnancy weight appears an important target for reducing adverse perinatal outcomes in a second pregnancy.
Level of evidence: II.