Obstetric and neonatal outcomes of extremely obese pregnant women after late preterm gestation

Abstract Background Maternal obesity characterized by high body mass index(BMI) is linked to adverse maternal and neonatal outcomes. However, insufficient data exist about the impact of extreme obesity on pregnancy within the Asian population. Objective To determine the obstetric and neonatal outcomes of pregnant women with extreme obesity at birth after late preterm gestation. Methods A retrospective study on extremely obese pregnant women with BMI ≥ 40kg/m2, obesity class III, excluding fetal death in utero and preterm births before 34 weeks of gestation. Obstetric and neonatal outcomes were reviewed. Results The study involved 94 extremely obese pregnant women (median BMI at delivery: 42.4 kg/m2). In relation to the prepregnancy BMI obesity class II category, higher chronic hypertension rates were found in allegedly extremely obese women compared to those with lower pre-pregnancy BMI (34% vs. 10%, p = 0.012), while the tocolytics use for preterm labour was higher in the BMI < 35.0 kg/m2 group (26% vs. 5%, p = 0.007). Adverse neonatal outcomes, including neonatal intensive care unit admission, use of respiratory support and jaundice were higher in the pre-pregnancy BMI < 35.0 kg/m2 group than the BMI ≥ 35.0 kg/m2 group (all p-values < 0.05). The use of neonatal support increased with lower pre-pregnancy BMI and with higher weight gain during pregnancy. Conclusions In extremely obese women(class III) who delivered during late preterm gestation, the use of tocolytics for preterm labour and the incidence of adverse neonatal respiratory outcomes appeared to be higher among those who were less obese before pregnancy than among those who were already extremely obese.