Alcohol Consumption During Pregnancy and Risk of Placental Abnormality: The Japan Environment and Children's Study.

There have been no large nationwide birth cohort studies examining for the effects of maternal alcohol use during pregnancy on placental abnormality. This study searched for associations between alcohol consumption and the placental abnormalities of placenta previa, placental abruption, and placenta accreta using the fixed dataset of a large national birth cohort study commencing in 2011 that included 80,020 mothers with a singleton pregnancy. The presence of placental abnormalities and potential confounding factors were recorded, and multiple logistic regression analysis was employed to search for correlations between maternal alcohol consumption during pregnancy and placental abnormalities. The overall rate of prenatal drinking until the second/third trimester was 2.7% (2,112). The prevalence of placenta previa, placental abruption, and placenta accreta was 0.58% (467), 0.43% (342), and 0.20% (160), respectively. After controlling for potential confounding factors, maternal alcohol use during pregnancy was significantly associated with the development of placenta accreta (OR 3.10, 95%CI 1.69-5.44). In conclusion, this large nationwide survey revealed an association between maternal drinking during pregnancy and placenta accreta, which may lead to excessive bleeding during delivery.