Associations of Preconception Body Weight, Body Mass Index, and Hypertension with Preeclampsia

Objective: Maximizing preconception health is an important strategy to prevent preeclampsia in pregnancy. Preeclampsia remains a significant cause of maternal and fetal morbidity and mortality. We examined the associations between preconception maternal body weight, body mass index (BMI), and blood pressure with preeclampsia and its related outcomes. Materials and Methods: We performed a retrospective review of 11,214 live births from 6 months preconception during 2009-2018 in the University of Washington medical system. Outcomes were analyzed using chi-square, analysis of variance, and t-tests. Binary logistic regression was performed to examine associations. Results: Of 11,214 births, 1,539 (13.7%) were complicated by preeclampsia. Individuals with preeclampsia weighed more and had higher blood pressure from 6 months preconception to at least 6 months of pregnancy compared with those without preeclampsia (p < 0.001). Persons with prepregnancy systolic blood pressure (SBP) ≥130 mmHg were 3.2 times more likely to develop preeclampsia than those with SBP <130 mmHg (adjusted odds ratio [aOR] = 3.24, 95% confidence interval [CI] = 2.37-4.43). Women with prepregnancy BMI ≥30 kg/m² were 2.3 times more likely to develop preeclampsia (aOR = 2.31, 95% CI = 1.72-3.10) than those with BMI <30 kg/m². Mothers with preeclampsia were more likely to deliver preterm (29% vs. 13.8%, p < 0.001) and have neonates with 5-minute Apgar scores <8 (22.1% vs. 12.1%, p = 0.02) and lower preterm birthweights (1,909 g, 95% CI = 1,813-2,004 g vs. 2,057 g, 95% CI = 1,989-2,123 g). Conclusions: Maternal obesity and elevated blood pressure from 6 months preconception to 6 months of pregnancy were associated with preeclampsia, resulting in maternal and fetal complications.