Pregnancy outcomes of refractory epilepsy patients treated with Brain–responsive neurostimulation

•It is the first reported cohort of pregnancy outcomes in women concurrently treated with RNS System.•No major congenital malformation in the offspring of 10 WWE treated with the RNS System.•One child from WWE with advanced maternal age and bicornuate uterus had a minor congenital anomaly.•Research highlighting the data of RNS system use during pregnancy is limited. To study the pregnancy outcomes, including obstetric complications and fetal outcomes, in pregnant women with epilepsy (WWE) treated with direct brain–responsive neurostimulation (RNS System). Retrospective review of obstetric outcomes and fetal outcomes in WWE treated with the RNS System at nine comprehensive epilepsy centers in the United States from 2014–2020. In addition, changes in seizure frequency, anti-seizure medications, and RNS System setting adjustments during pregnancy were investigated. A total of 10 subjects and 14 pregnancies were identified. The mean age at conception was 30.6 ± 4.3 years old. The mean age at implantation was 29.8 ± 4.4 years old. The mean stimulation charge densities ranged from 1.0 to 3.0 μC/cm2 during pregnancy. Obstetric complications included recurrent miscarriage (1 patient), cesarean section (3 patients) due to preeclampsia, non-reassuring fetal heart rate tracing or prolonged labor, preterm birth (1 patient), and preeclampsia (1 patient). No still birth, gestational hypertension, gestational diabetes, eclampsia, or maternal mortality were observed. No RNS System-exposed pregnancies had major congenital malformations. One offspring had a minor congenital anomaly of cryptorchidism in a pregnancy complicated with risk factors of advanced maternal age and bicornuate uterus. The present study is the first report of RNS System-exposed pregnancies in WWE to date. No major congenital malformations were identified. All of the obstetric complications were within the expected range of those in WWE based on previously published data. The sample size of our study is small, so accumulation of additional cases will further help depict the safety profile of treatment with the RNS System during pregnancy.