Prepregnancy body mass index as an important predictor of perinatal outcomes in Japanese.

OBJECTIVE: The influence of maternal body mass index (BMI) before pregnancy and weight gain during pregnancy on perinatal outcomes in the Japanese population remains to be elucidated. Therefore, we estimated the risk of perinatal morbidity of the mother and infant with respect to maternal prepregnancy BMI and weight gain during pregnancy in Japanese.

RESULTS: In the obese before pregnancy group, the risks of cesarean delivery, preeclampsia, and gestational diabetes were significantly elevated compared with the normal group. In the underweight before pregnancy group, the risks of low birth weight infant and hospitalization of infant were elevated significantly.

CONCLUSION: However, weight gain during pregnancy did not show any significant influence on the perinatal outcomes of the mother or infant.