Morbidity and rehospitalization postpartum among women with epilepsy and their infants: A population-based study.

Objective: We compared the relative occurrence of selected pregnancy outcomes and postpartum rehospitalizations among women with and without epilepsy and their infants. Using linked vital-hospital discharge records of women with deliveries in Washington State 1987-2014, comparisons were made overall, by epilepsy type, and by time periods related to antiepileptic drug (AED) marketing changes.

Methods: This population-based retrospective cohort study identified women with, and without epilepsy per diagnosis codes in the hospital discharge record from among all deliveries during 1987-2014 to examine maternal and infant outcomes, rehospitalization and mortality <2 years postpartum. Relative risks (RRs) and 95 % confidence intervals (CI) overall, and by epilepsy type were calculated using Poisson regression. We assessed the validity of epilepsy identification based on diagnosis codes by conducting a medical chart review for a sample of women.

Results: Women with epilepsy had increased risks of preeclampsia (RR 1.23; 95 % CI 1.08-1.41) and gestational diabetes (RR 1.18; 95 % CI 1.02-1.36). Their infants had increased malformation (RR 1.23; 95 % C: 1.08-1.42) and small for gestational age (SGA, RR 1.39; 95 % CI 1.25-1.54) risks, and were nearly three times as likely to not be breastfed. Affected mothers (RR 5.25; 95 % CI 2.46-11.23) and their infants (RR 1.64, 95 % CI 1.41-1.89) required more ICU admissions during the delivery hospitalizations, and more postpartum rehospitalization, with greatest risk in the first six months. Maternal mortality < 2 years after delivery was increased (RR 7.11; 95 % CI 2.47-20.49). Increased risks were observed for all epilepsy subtypes for nearly all outcomes examined. Risks of preterm delivery and low birthweight increased over time (p <.05). Suggestive, but not statistically significant temporal decreases in risks of gestational diabetes and malformations and increased risk of preterm labor were noted. We observed high sensitivity of diagnosis codes for identifying pregnant women with epilepsy.

Conclusion: These population-based results emphasize the need for frequent postpartum monitoring of women with epilepsy. Increases in risks of low birthweight and preterm delivery over time are of concern. Possible temporal changes in other outcomes warrant further investigation.