Severe, uncontrolled epilepsy in pregnancy: A population-based case-control study.

Background: Epilepsy affects one percent of the UK population and is the most common serious neurological condition experienced during pregnancy. We compared the characteristics, clinical management, and pregnancy outcomes in women with severe, uncontrolled epilepsy to those of women with well controlled disease.

Methods: We conducted a population-based case-control study in all UK consultant-led maternity units. Cases of severe uncontrolled epilepsy during pregnancy were identified prospectively and reported via the UK Obstetric Surveillance System (UKOSS). Severe epilepsy was defined a-priori as ≥1 of the following: admission to hospital during pregnancy to manage seizures; prescribed ≥3 antiepileptic medications; or died from epilepsy. Controls comprised women with epilepsy not meeting the case definition, identified within the same centres as cases. Pre-pregnancy epilepsy control and pregnancy outcomes were compared between groups using multivariable logistic regression.

Results: We identified 94 cases between 1 October 2015 and 31 March 2017 and compared these with 186 controls. Cases were significantly more likely to be admitted to manage seizures in the year preceding pregnancy (42/94 cases vs 10/186 controls, adjusted odds ratio [aOR]=7.38 [95% CI 2.70-20.2]), and to report their most recent seizure within 3 months of pregnancy (51/94 cases vs 18/186 controls, aOR=5.86 [95% CI 2.30-15.0]). Cases were significantly more likely to deliver before 37 weeks (20/94 cases vs 8/186 controls, aOR=7.61 [95% CI 2.87-20.2]).

Conclusions: Women admitted for seizure management in the year before pregnancy are at higher risk of severe epilepsy during pregnancy and of preterm birth. These women should be prioritised for discussion about pregnancy and contraception. When pregnant, they should be reviewed as early as possible by specialists in the management of epilepsy during pregnancy. Delivering messages about the importance of pregnancy planning and contraception to all women with epilepsy should be viewed as the responsibility of all clinicians involved their care.