OBJECTIVE: To investigate associations between maternal epilepsy and pregnancy, delivery and neonatal outcomes. METHODS: A population-based retrospective cohort study was conducted using the Healthcare Cost and Utilization Project, Nationwide Inpatient Sample (HCUP-NIS) database, between 2004-2014. Through logistic regression analysis, we compared associations between epilepsy and pregnancy-related outcomes while adjusting for demographic characteristics and comorbidities. RESULTS: Of 9,096,788 pregnancies, 25,044 were in pregnant women with epilepsy (PWWE). PWWE were more likely to be younger, white or black, have a lower income and to be insured through Medicare or Medicaid. Furthermore, PWWE were more likely to have been diagnosed with obesity, chronic hypertension, gestational diabetes, thyroid disease and HIV, and to have smoked tobacco during pregnancy or used illicit drugs. Pregnancy and delivery outcomes associated with epilepsy include pregnancy-induced hypertension(adjusted OR(aOR):1.26, 95 %CI:1.21-1.32), preeclampsia(aOR:1.33, 95 %CI:1.26-1.41), eclampsia(aOR:8.34, 95 %CI:7.14-9.74), superimposed preeclampsia/eclampsia(aOR:1.29, 95 %CI:1.14-1.47), placenta previa(aOR:1.24, 95 %CI:1.06-1.44), preterm delivery(aOR:1.27, 95 %CI:1.21-1.32), abruptio placenta(aOR:1.24, 95 %CI:1.12-1.36), chorioamnionitis(aOR:1.12, 95 %CI:1.02-1.23), cesarean section(aOR:1.29, 95 %CI:1.25-1.33), hysterectomy(aOR:1.79, 95 %CI:1.31-2.45), postpartum hemorrhage(aOR:1.12, 95 %CI:1.05-1.21), wound complications(aOR:1.38, 95 %CI:1.17-1.63), maternal death(aOR:3.42, 95 %CI:1.79-6.53), transfusion(aOR:1.67, 95 %CI:1.53-1.83), maternal infection(aOR:1.18, 95 % CI:1.09-1.28, p <
0.001), deep vein thrombosis(aOR:2.11, 95 %CI:1.43-3.10), pulmonary embolism(aOR:2.98, 95 %CI:1.87-4.76), venous thromboembolism(aOR:2.25, 95 %CI:1.65-3.08) and disseminated intravascular coagulation(aOR:1.48, 95 %CI:1.19-1.83). Epilepsy-linked neonatal complications include small for gestational age(aOR:1.52, 95 %CI:1.43-1.62), intrauterine fetal demise(aOR:1.20, 95 %CI:1.02-1.41) and congenital anomalies(aOR:2.76, 95 %CI:2.47-3.07). CONCLUSIONS: PWWE have significantly higher risk of nearly every pregnancy, delivery and neonatal complication investigated, including maternal death and intrauterine fetal demise. PWWE should be considered high risk patients and be carefully followed during pregnancy.