Maternal Obesity and the Risk of Placenta Vascular Disease

Introduction: While elevated maternal weight in early pregnancy is associated with a higher rate of preeclampsia, the risk of placental abruption and placental infarction is unknown. Methods: We evaluated the risk of placental abruption, placental infarction, and preeclampsia in association with maternal weight quintile at approximately 17 weeks' gestation in 386 323 women with a singleton pregnancy who underwent maternal serum screening in Ontario. Results: After adjusting for age, ethnicity, parity, diabetes mellitus, and tobacco use, the odds ratio (OR) for preeclampsia was 4.1 (95% confidence interval [CI] 3.8-4.4) comparing the highest and lowest weight quintiles. Conversely, there was a lower risk of placental abruption or placental infarction, despite further adjustment for preeclampsia, gestational hypertension and drug dependence (OR 0.81, 95% CI 0.75-0.87). Conclusion: Higher maternal weight in early pregnancy is associated with a higher risk of preeclampsia and a lower risk of placental abruption or placental infarction, a seeming paradox that requires further elucidation.