Antenatal and intrapartum risk factors for neonatal hypoxic ischemic encephalopathy. 
To identify antenatal and intrapartum risk factors for neonatal hypoxic ischemic encephalopathy (HIE).  A single center, retrospective cohort study was conducted for 25,494 singleton births ≥36 weeks' gestation born between 2009 and 2016.  Univariate and multivariate analyses were performed to identify risk factors for HIE.  Thirty-seven infants met HIE inclusion criteria.  Independent antenatal risk factors included primigravida, previous fetal death/stillbirth, antidepressant use, illicit drug use, Rh sensitization, and adjusted gestational weight gain >13.6 kg.  Independent intrapartum risk factors identified were placental abruption, ruptured uterus, moderate-to-heavy meconium stained amniotic fluid, and delivery by cesarean-section.  An intrapartum risk factor was present in 70.3% of the HIE group compared with 29.6% of the non-HIE group.  Intrapartum period risk factors appear to be important for the development of HIE.  Gestational weight gain may serve as an important modifiable factor to reduce the risk of HIE.