OBJECTIVE: To estimate whether vaginal delivery or neuraxial anesthesia poses a risk of neurologic deterioration in women with uncorrected Chiari I malformation.
METHODS: To assemble this case series, electronic record databases were used to identify women with Chiari I malformation who delivered on two busy tertiary care obstetric services over a 5-year period from January 2010 through December 2015. Women who had undergone surgical decompression were not included in the study. The size of the Chiari malformation, neurologic symptoms before delivery, mode of delivery, anesthetic method used, and neurologic complications were recorded.
RESULTS: Ninety-five deliveries in 63 patients were identified. The size of the Chiari malformation was 9.3±4.3 mm (mean±SD). In 58 pregnancies, women reported no headaches; in 36 they did. There was no association between the size of the Chiari malformation and the incidence of headache. Forty-four neonates were delivered by cesarean delivery and 51 were delivered vaginally. No neurologic deterioration occurred in either group. Neuraxial anesthesia was administered before 62 deliveries. No neurologic complications occurred. None of the women who delivered vaginally or received neuraxial anesthesia had signs of increased intracranial pressure. The upper limit of the 95% CI for the risk of neurologic complications from our study of 95 deliveries was 3.1%.
CONCLUSION: This case series support that in patients with Chiari I malformation who have no signs of increased intracranial pressure, the mode of delivery should be based on obstetric rather than neurologic considerations. The absence of complications in patients who received epidural or spinal anesthesia suggests that these procedures should be made available to women with Chiari I malformation.