A 23-year-old woman with JME and obesity who had previously failed 7 prior ASMs presented with planned pregnancy. She was presently well-controlled on a regimen of CBD 1960mg/day (21mg/kg/d), brivaracetam 150mg/day, and folic acid. Upon finding out that she was pregnant, she was maintained on her same ASMs as her seizures were previously refractory and were currently very well controlled on her current regimen. We checked monthly serum levels of CBD and brivaracetam during her pregnancy.

Baseline CBD level was 340ng/ml. At 14 weeks of gestation, level dropped to 99ng/ml and dose was increased to 2150mg/day (23mg/kg/d). Her level increased to 310ng/ml by 18 weeks. By week 22 her level dropped to 120ng/ml and her dose was increased to 2480mg/day (24.8mg/kg/d). By week 36 her dose had decreased to 23.7mg/kg/d due to expected weight gain but her serum level was stable (210ng/ml), and no additional changes were made. She remained seizure free throughout her pregnancy. Her pregnancy was complicated by gestational diabetes, fetal macrosomia, and polyhydramnios. She underwent spontaneous vaginal delivery of a healthy infant at 39 weeks. Delivery was complicated by shoulder dystocia and a third-degree perineal laceration.

This is the first case report showing how CBD levels change during pregnancy in humans. Weight-based dosing remained essentially unchanged, but monthly serum levels are recommended in pregnancy. The patient had some pregnancy complications (not likely related to ASM), but gave birth to a healthy infant. Further research is needed to help guide the management of CBD dosing in pregnant patients.