Anti-Seizure Medicines in Pregnancy
April 2018 - September 2024

About this release

This release by Public Health Scotland reports on anti-seizure medicines (ASMs) prescribed to patients in Scotland aged 0-54, with a particular focus on pregnant women. For the first time, data on ASM prescribing in males aged 0-54 has been added, following new guidance on valproate published in January 2024 (and since updated in February 2025). ASMs are used in the management of epilepsy, but also for other conditions such as migraine, bipolar disorder, and some types of pain. The reason for prescribing is not known therefore prescribing data is included for all conditions.

This summary presents the key messages on prescribing of valproate and topiramate. Further information is available on these and other ASMs in the accompanying dashboard.

Valproate taken during pregnancy is known to be associated with an increased risk of both congenital and neurodevelopmental conditions. There is also a possible association between use of valproate by men around the time of conception and an increased risk of neurodevelopmental conditions in their children. Topiramate taken during pregnancy is associated with a higher risk of congenital conditions, low birth weight and a potential increased risk of neurodevelopmental conditions. For full details and prescribing guidance please see MHRA advice for valproate and topiramate.

For a more detailed review of the safety of anti-seizure medicines in pregnancy see the January 2021 report published by the Commission on Human Medicines (CHM).

For more detailed information, please see the commentary section of the dashboard.

Main points

Valproate prescribing

• 2,210 females were prescribed valproate in the most recent quarter reported (July – September 2024). This has decreased by 48% (from 4,237) since the quarter April – June 2018.
• There were 40 female new starts (females prescribed valproate for the first time in 12 months) in July - September 2024. This has decreased by 69% from 128 in April – June 2018.
• 5,876 males were prescribed valproate in the most recent quarter reported (July – September 2024). This is a decrease of 9% on the 6,443 males treated in October – December 2023, prior to guidance released in January 2024.
• There were 97 male new starts (males prescribed valproate for the first time in 12 months) in July - September 2024. This has decreased by 48% from 186 in October – December 2023.

Topiramate prescribing

• 3,880 females were prescribed topiramate in the most recent quarter reported (July – September 2024). This figure has decreased by 7% (from 4,171) since the quarter April – June 2018.
• There were 336 female new starts (females prescribed topiramate for the first time in 12 months) in July – September 2024. This has decreased by 50% from 669 in April – June 2018.

Line chart showing trend in new starts for valproate in males and females and topiramate in females. All three have shown a decrease from April 2018 to September 2024.

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Chart 1: Valproate and topiramate new starts by quarter of prescribing

Valproate prescribing in pregnancy

• 2 pregnancies conceived between July 2023 and December 2023 (the most recent 6 month period where all pregnancies have had time to complete) were exposed to valproate.
• Both pregnancies were exposed to valproate in early pregnancy (first trimester).
• None of these exposures were a result of a woman being newly prescribed valproate during pregnancy (with no prescription in the year before pregnancy).
• In 5 pregnancies conceived between July 2023 and December 2023, the woman had a prescription for valproate in the year before pregnancy but none during pregnancy.

Topiramate prescribing in pregnancy

• 16 pregnancies conceived between July 2023 and December 2023 (the most recent 6 month period where all pregnancies have had time to complete) were exposed to topiramate.
• All 16 pregnancies were exposed to topiramate in early pregnancy (first trimester).
• 2 of these exposures were a result of women being newly prescribed topiramate during pregnancy (with no prescription in the year before pregnancy). It is possible that these women had previous prescriptions, but the prescribing record was not available for our analysis.
• In 39 pregnancies conceived between July 2023 and December 2023, the woman had a prescription for topiramate in the year before pregnancy but none during pregnancy.

Line chart showing trend in pregnancies exposed to valproate and topiramate. Both have been decreasing from April 2018 to December 2023 which is the latest time period for which complete pregnancy information is available.

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Chart 2: Pregnancies exposed to valproate and topiramate by quarter of conception - quarterly average^1,2

1. Quarterly average is based on the average of the previous four quarters.
2. The shaded area indicates the period after January 2024, where numbers may start to decline as there may be pregnancies that are still ongoing on 30 September 2024 that had not been exposed up to that point and may become exposed as the pregnancy progresses.

Background

Information on anti-seizure medicines dispensed in community pharmacies and by dispensing doctors, administered during hospital stays, and supplied through Home Care services were combined with pregnancy and births data. Further information on the data can be found in the dashboard.

Further information

The next release of this publication will be October 2025.