Pregnancy Outcomes in Refractory Epilepsy Patients with Vagus Nerve Stimulation: Long-Term Single-Center Experience

Background and Study Aims Vagus nerve stimulation (VNS) has been employed worldwide as an adjunctive therapy in drug-resistant epilepsy patients. However, the mechanisms of VNS action potentially increase the risk of obstetric complications. The study presents the long-term single-center experience with pregnancies and childbirth in women with VNS for refractory epilepsy based on prospectively collected epileptologic data and a retrospective analysis of pregnancy, childbirth, and data about long-term child development. Material and Methods From a group of patients with VNS implanted for refractory epilepsy between October 1999 and January 2018, all the women of childbearing age (younger than 40 years) were identified. After checking their hospital records for data about any pregnancies, the women with confirmed childbirth during active VNS stimulation and their general practitioners were interviewed based on a prepared questionnaire regarding their gynecologic history, the course of pregnancy and childbirth, gestational week, birth weight and length, any congenital anomalies of the child, and the child's psychomotor development, school performance, and somatic health problems. Results From the group of 257 patients implanted with VNS for refractory epilepsy, 4 women (1.5%) became pregnant and gave birth (all on polypharmacotherapy). The mean interval from VNS implantation to birth was 44.3 months. Slight seizure worsening during the last trimester was reported in one woman. In one patient, acute caesarean section was required due to placental separation. Planned birth induction and caesarean section were used in the other two women because of their seizure disorder. No malfunction of the stimulation system was detected during pregnancy or after birth. No congenital malformations were observed. The two children who were of school age at the time of this study require special schooling. Conclusions The study results confirmed a high rate of obstetric interventions in patients with VNS. Although no teratogenic effect of VNS has been proven, the higher incidence of children exposed to VNS needing special education requires attention.