Anti-Seizure Medicines in Pregnancy
April 2018 - March 2024

About this release

This release by Public Health Scotland is the second report on anti-seizure medicines (ASMs) prescribed to females in Scotland aged 0-54 and pregnant women. These medicines are also used in the management of other conditions such as migraine, bipolar disorder, and some types of pain. The reason for prescribing is not known and therefore prescribing data is included for all conditions.

This summary presents the key messages in prescribing of valproate and topiramate to women aged 0-54 as well as the prescribing of these medicines during pregnancy. Further information is available on these and other anti-seizure medicines in the accompanying dashboard.

Valproate taken during pregnancy is known to be associated with an increased risk of both congenital and neurodevelopmental conditions. Topiramate taken during pregnancy is associated with a higher risk of congenital malformation, 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 a more detailed discussion of the background please see the full report from the first release of this data in April 2024.

Main points

Of the 153,340 females aged 0-54 prescribed an anti-seizure medicine between April 2018 and March 2024:

• 58,091 females were prescribed an anti-seizure medicine in the most recent quarter reported (January – March 2024). This figure has remained stable throughout the full period reported (April 2018 – March 2024).

Valproate

• 6,008 females were prescribed valproate between April 2018 and March 2024.
• 2,326 were prescribed valproate in the most recent quarter reported (January – March 2024). This figure has decreased by 45% (from 4,236) since the quarter April – June 2018.
• 78 pregnancies (to 70 women) conceived between April 2018 and March 2024 had been exposed to valproate by 31 March 2024.
• Of the 78 valproate-exposed pregnancies conceived between April 2018 and March 2024, 76 (97%) had been exposed during early pregnancy (first trimester).
• In 7 of the 78 valproate-exposed pregnancies conceived between April 2018 and March 2024, valproate was started during pregnancy after the woman had no prescription in the year before pregnancy. It is possible that some of these women had previous prescriptions, but the prescribing record was not available for our analysis.
• In 60 pregnancies conceived between April 2018 and March 2024 the woman had a prescription for valproate in the year before pregnancy but none during pregnancy.

Graph showing numbers of females prescribed valproate and topiramate over time from April 2018 to March 2024. Valproate prescribing in this group has reduced by 45% whereas topiramate prescribing has remained steady.

Close

Chart 1: Overall prescribing of valproate and topiramate in females aged 0-54

Graph showing a trend in pregnancies exposed to valproate and topiramate. Figures plotted are quarterly averages. For both medicines these are reducing.

Close

Chart 2: Pregnancies exposed to valproate and topiramate ^1,2

1. Quarterly average is based on the average of the previous four quarters.
2. The shaded area indicates the period after June 2023, where numbers may start to decline as there may be pregnancies that are still ongoing on 31 March 2024 that had not been exposed up to that point and may become exposed as the pregnancy progresses.

Topiramate

• 16,187 females were prescribed topiramate between April 2018 and March 2024.
• 4,110 were prescribed topiramate in the most recent quarter reported (January – March 2024). This figure has remained level since the quarter April – June 2018.
• 281 pregnancies (to 251 women) conceived between April 2018 and March 2024 had been exposed to topiramate by 31 March 2024.
• Of the 281 topiramate-exposed pregnancies conceived between April 2018 and March 2024, 277 (99%) had been exposed during early pregnancy (first trimester).
• In 42 of the 281 topiramate-exposed pregnancies conceived between April 2018 and March 2024, topiramate was started during pregnancy after the woman had no prescription in the year before pregnancy. It is possible that some of these women had previous prescriptions, but the prescribing record was not available for our analysis.
• In 602 pregnancies conceived between April 2018 and March 2024 the woman had a prescription for topiramate in the year before pregnancy but none during pregnancy.

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 April 2025.