Objectives: This study examined the associations between prepregnancy weight and the risk of pregnancy complications and adverse outcomes among nulliparous women.
Methods: We conducted a population-based cohort study with 96,801 Washington State birth certificates from 1992 to 1996. Women were categorized by body mass index. Multivariate logistic regression was performed.
Results: The rate of occurrence of most of the outcomes increased with increasing body mass index category. Compared with lean women, both overweight and obese women had a significantly increased risk for gestational diabetes, preeclampsia, eclampsia, cesarean delivery, and delivery of a macrosomic infant.
Conclusions: Among nulliparous women, not only prepregnancy obesity but also overweight increases the risk of pregnancy complications and adverse pregnancy outcomes.