Abstracts

Rationale: Since the advent of prospective epilepsy and pregnancy registries over the last 20 years the teratogenic effects of certain anti-epileptic drugs have become increasingly well known among prescribers, with temporal prescribing trends favouring less teratogenic anti-epileptic drugs (AEDs). Our aim was to determine if any shifts in prescribing trends have occurred in our cohort, and to what extent this may have influenced the rate of major congenital malformation (MCM). Methods: The UK and Ireland Epilepsy and Pregnancy Registry was established in 1996. It is a prospective, observational, registration and follow up study. We determined the changes in AEDs utilised during pregnancy and the MCM rate between 1996 and 2016. Results: Outcome data were available for 9247 pregnancies. Ratio of polytherapy, to monotherapy remained stable across the time period. Statistically significant increases in the monotherapy use of lamotrigine (p < 0.0001) and levetiracetam (p < 0.0001), and decreases in the use of valproate (p < 0.0001) and carbamazepine (p < 0.0001) were observed. Significantly less valproate was prescribed in polytherapy regimes (p < 0.0001). Between 1996 and 2016 there was a fall in the total MCM rate from 4.19% (95% CI 3.61-4.87) to 3.10% (95% CI 2.62-3.67) (p=0.009). Conclusions: The overall MCM rate in our cohort decreased relatively by 26% during the duration of the study, if extrapolated to all women with epilepsy (WWE) in the United Kingdom (2500 – 3000 births to WWE per annum), this approximates to potentially 27 - 32 fewer MCMs per annum. Funding: The first author has not received any funding for the preparation of this paper. Unrestricted educational grants have been received from Eisai, Glaxo Smith Kline, Novartis, Sanofi-Aventis, Pfizer and UCB for the running of the UK Epilepsy and Pregnancy Register.