Examining the Joint Effects of Epilepsy and Mental Health Conditions on Severe Maternal Morbidity.

Background: Mental health conditions and epilepsy frequently coexist and have independently been associated with severe maternal morbidity (SMM). Since little is known about the risks of these conditions when they occur together in pregnancy, we evaluated the associations of mental health conditions, epilepsy, and SMM. Methods: We conducted a population-based study of births in California between 2007 and 2018. Antenatal epilepsy and mental health conditions (defined as depression, anxiety, posttraumatic stress disorder, and other) were identified using billing codes. We categorized individuals into the following mutually exclusive exposure groups: no epilepsy or mental health conditions (referent), mental health conditions alone, epilepsy alone, or both epilepsy and mental health conditions. Our primary outcome was SMM, defined by the 20-indicator Centers for Disease Control and Prevention Index. We conducted multivariable logistic regression models adjusted for sociodemographic and clinical confounding factors. Results: In a cohort of 5,275,994 births, SMM occurred more frequently in individuals with mental health conditions alone, epilepsy alone, and both mental health conditions and epilepsy (1.8%, 3.0%, 4.2%, respectively) compared with the referent group (0.8%). The odds of SMM were significantly increased for each exposure group: adjusted odds ratio (aOR) 2.13, 95% confidence interval (CI) 2.05-2.22 for mental health conditions; aOR 3.79, 95% CI 3.45-4.18 for epilepsy; and aOR 4.91, 95% CI 4.01-6.00 for both. Conclusion: Epilepsy and mental health conditions were independently associated with SMM, and individuals carrying both diagnoses had the highest odds of SMM. Our results highlight the need for awareness of SMM risks in this population.