Prescription of antiepileptic medicines including valproate in pregnant women: a study in three European countries

Purpose: To study patterns of antiepileptic drugs (AED) prescribing, particularly valproate, during pregnancy over a 10-year period in the UK, Italy, and France. Methods: Data on pregnancies conceived after 1 January 2007 with outcomes before 31 December 2016 were extracted from four European electronic health care databases (380 499 in the United Kingdom (UK), 66 681 in France, and 649 918 in Italy [355 767 in Emilia Romagna and 294 151 in Tuscany]). Prevalence of AEDs with an ATC code starting N03A and clobazam (N05BA09) were stratified by country and calendar year. Results: AED prescribing during pregnancy varied from 3.0 (2.8-3.1) per 1000 pregnancies in Emilia Romagna to 7.8 (7.5-8.0) in the UK, 5.9 (5.6-6.1) in Tuscany, and 6.3 (5.7-6.9) in France. Lamotrigine was commonly prescribed in all regions with a third of women exposed to an AED during pregnancy taking lamotrigine in the UK and France. Valproate was prescribed to 28.6% of AED exposed pregnant women in Tuscany, 21.6% in France, 16.7% in Emilia Romagna, and 11.9% in the UK. Over the study period, the prevalence of AED prescribing increased in the UK mainly due to increases in pregabalin and gabapentin, declined in France mainly related to decreases in clonazepam, and remained constant in Italy. Valproate prescriptions declined to a prevalence <1 per 1000 pregnancies in 2015 to 2016 in the UK, France, and Emilia Romagna. Conclusions: Variations in AED prescribing during pregnancy indicate the potential for further reductions, particularly of valproate. Increases in pregabalin/gabapentin prescribing, for which risks are not well known, are a cause for concern.