Maternal obesity and the risk of placental vascular disease.

BACKGROUND

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).

CONCLUSIONS

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.