The effect of maternal Class III obesity on neonatal outcomes: a retrospective matched cohort study

Objectives: To compare outcomes of neonates born from women with Class III obesity with those whose mothers were of normal body weight. Methods: A retrospective cohort study of live-born singleton infants was undertaken. Maternal prepregnancy body mass index (BMI) defined matched normal and Class III obese cohorts. Multivariable regression models were used to determine adjusted relative odds ratios (aOR) and 95% confidence intervals (CI) for selected adverse neonatal outcomes. Results: Newborns exposed to maternal Class III obesity had greater risks of fetal overgrowth and low cord artery pH. Class III obesity was protective against small for gestational age and low birthweight. There was no difference in the risk of preterm delivery, meconium in the amniotic fluid or breastfeeding initiation. Conclusions: The new knowledge generated by this study provides further information on unique challenges faced by newborns of women with Class III obesity, suggesting more specialized care in the intrapartum and neonatal periods may be beneficial.