Rising use of antiseizure medications in pregnancy reported

Many women continue to use antiseizure medications (ASMs) during pregnancy despite data indicating risks of malformations at birth, according to a recent study published in Neurology.¹

The data highlighted a significant increase in the odds of ASM use among pregnant women with a low level of resources vs those with a high level of resources. Additionally, pregabalin and gabapentin had the most significant increases in use over the study period of 28%.¹

“These medications can be used for epilepsy, mood disorders, chronic pain and migraine, which often occur at young ages, and sometimes people are taking them before they realize that they are pregnant,” said Rosemary Dray-Spira, MD, PhD, study author from the French National Agency for the Safety of Medicines and Health Products.¹

Nationwide study tracks trends over nearly a decade

Investigators conducted the nationwide population-based study to assess prenatal ASM exposure trends over the past decade.² Data was obtained from the National Mother-Child Register EPI-MERES, which includes pregnancies in France from 2010 onwards.

Pregnant women aged 15 to 49 years with prenatal ASM exposure from January 1, 2013, to December 31, 2021, and at least 1 health expenditure reimbursement within 2 years before pregnancy onset were included in the analysis. ASM dispensation within 30 days before conception or during pregnancy was defined as the exposure.²

There were 3 categories of ASMs, the first being the safest. This included lamotrigine and levetiracetam. The second category included ASMs with uncertain risk such as gabapentin, pregabalin, oxcarbazepine, clonazepam, and newer ASMs, while the third included those with acknowledged risk such as valpromide, carbamazepine, valproic acid, topiramate, and others.²

Maternal sociodemographic and pregnancy factors such as level of resources, age at pregnancy, livebirth, stillbirth, and pregnancy termination were also obtained. International Statistical Classification of Diseases and Related Health Problems, 10th revision codes were used to identify maternal health conditions linked to ASM use.²

Prevalence and types of ASM exposure

There were 55,801 pregnancies exposed to at least 1 ASM during the study period, 49.9% of which were exposed to the safest ASMs, 34.9% those with uncertain risk, and 24.2% those with acknowledged risk. An overall consistent number of ASM-exposed pregnancies was reported between 2013 and 2021, with a median of 6200.²

Different trends were reported across the study period based on ASM safety categories. Between 2013 and 2021, increases of 30% and 33% were reported in the use of ASMs in the safest category and with uncertain risk, respectively. This included a 22% increase in lamotrigine, 64% in levetiracetam, 49% in pregabalin, and 27% in gabapentin.²

Similarly, newer ASM use increased by 140% However, declines were reported in the use of ASMs with acknowledged risk, at -66% overall, -84% for valproic acid, -89% for valpromide, -40% for carbamazepine, and -34% for topiramate.²

Pregnancy outcomes vary by ASM safety category

Pregnancies exposed to the safest ASMs had similar pregnancy characteristics to those unexposed, with mean maternal ages of 30.2 vs 29.7 years, respectively, and low level of resources rates of 18.7% vs 20.4%, respectively. Live birth rates were 74.3% and 73.1%, respectively.²

An older mean maternal age and higher level of socioeconomic deprivation were reported in mothers exposed to ASMs with uncertain risk, at 31.9 years and 18.5%, respectively. Similarly, these values were 31.2 years and 17.9%, respectively, in those exposed to ASMs with acknowledge risks.²

Interruption was reported in 24.9% of mothers exposed to ASMs with uncertain risk vs 32.4% of those acknowledged risk. All ASM-exposed pregnancies reported an increasing level of socioeconomic deprivation regardless of ASM safety category.²

Call for preventive measures

Overall, the data highlighted notable increases in lamotrigine and levetiracetam use over the prior decade, alongside newer ASMs. Investigators concluded measures are needed to reduce the risk of prenatal ASM exposure, especially in patients with a low level of resources.²

“The good news is that use of the drugs with the greatest risks has decreased, and use of the safest drugs has increased, but we are concerned to still see use during pregnancy of some drugs with known risks and new drugs with uncertain risk,” said Dray-Spira.¹

References

1. Use of antiseizure drugs with known or uncertain risks during pregnancy continues. American Academy of Neurology. July 23, 2025. Accessed July 4, 2025. https://www.eurekalert.org/news-releases/1092035.
2. Shahriari P, Drouin J, Miranda S, Bougas N, Botton J, Dray-Spira R. Trends in prenatal exposure to antiseizure medications over the past decade: A nationwide study. Neurology. 2025;105(4). doi:10.1212/WNL.0000000000213933