Authors :
Presenting Author: Sabrina Chan, BSc – University of Toronto
Jason Ward, BSc – Mass General for Children
Moira Quinn, MSN,FNP-C, DCNP – Mass General for Children
Frances High, MD, PhD – Mass General for Children
Esther Bui, MD, FRCPC, CSCN (EEG) – University of Toronto
Rationale:
Pregnant patients with epilepsy (PPWE) have unique obstetrical management considerations. Prior Canadian studies (e.g., Hebert et al., 2024) have shown that most PPWE were on antiseizure medications, often monotherapy, and that seizure control before pregnancy best predicts stability during pregnancy. While these studies offer valuable insights, national data on care patterns remain limited. This study aims to explore the obstetrical care of Canadian PPWE over the past 3 decades.
Methods: A subgroup analysis was conducted with 449 Canadian mothers who were enrolled in the North American Anti-epileptic Drug Pregnancy Registry (NAAPR) from 1997 to 2023. Data on anti-seizure medication use and maternal characteristics were collected through phone interviews at baseline (within 3 months of conception), 7 months gestation, and postpartum (within 3 months after delivery).
Results:
Participants were predominantly white (88.9%) and college graduates (55.8%). The average maternal age was 31.5 years old (SD = 4.72) with an average age of seizure onset of16.8 years old (SD = 7.97). The majority of participants lived in urban areas, with the largest population in Ontario (43.2%), followed by British Columbia (19.2%) and Alberta (18.9%). The majority of participants were on monotherapy (73.3%). Among all provinces, Saskatchewan had the highest proportion of participants in monotherapy (84.6%), whereas Quebec has the lowest (59.3%). The top three anti-seizure medications at the time of last menstrual period were lamotrogine (25.1%), carbamazepine (23%), and levetiracetam (21.1%) with average reported total daily dose of 309.8 mg (SD = 165.8, range 50-1500), 761.5 mg (SD = 492,4, range 100-3600), and 1651.4 mg (SD = 1005.3, range 125-4000) respectively. Lesser used drugs were topiramate (6.8%), valproic acid (6.1%), and clobazam (0.9%) with an average total daily dose of 250.9 mg (SD = 136.8, range = 25-500), 855.8 mg (SD = 136.8, range = 25-500), and 42.5 mg (SD = 33.0, 10-80) respectively. Among participants, 74% continued with their baseline medication(s) at 7 months gestation, and 75.5% of these patients continued baseline medications from 7 months until end of pregnancy. The majority of women (83.1%) reported using folic acid during pregnancy. All pregnancies resulted in live births with the average gestation at delivery of 39.3 weeks (SD = 2.3), with neonatal complications reported in 12.7% patients.
Conclusions:
This study provides one of the largest, multi-decade Canadian-specific data on PPWE to fill a critical gap in current research. Findings of this study can provide insight into important Canadian-specific differences compared to other population-based pregnancy registries.
Funding: N/A