Published: 23 September 2025
Safety Information
Alert communication
Topiramate: New measures and advice to prevent exposure during pregnancy
23 September 2025
Topiramate should not be used during pregnancy unless absolutely necessary. There are increased risks of congenital malformations (birth defects), neurodevelopmental disorders (learning and behavioural problems) and being small for gestational age in children whose mothers were taking topiramate during pregnancy.
The medicine sponsors are introducing new measures and advice to prevent topiramate exposure during pregnancy, including educational materials for patients and healthcare professionals.
Products affected
Advice for consumers and caregivers
Information for healthcare professionals
Further information
Useful links
References
Products affected
Topiramate is a medicine used to treat epilepsy in adults and children aged 2 years and older. It is also used in adults to prevent migraines.1, 2 Table 1 shows the approved topiramate products
Table 1: Approved topiramate products
| Product name | Sponsor |
|---|---|
| Topamax film coated tablet | Janssen-Cilag |
| Topamax sprinkle capsule | Janssen-Cilag |
| Topiramate Actavis film coated tablet | Teva Pharma |
Advice for consumers and caregivers
- Do not stop taking topiramate without talking to your doctor.
- Topiramate could harm the way an unborn baby grows and develops during pregnancy.
- Anyone who could get pregnant should use effective contraception while taking topiramate and for at least four weeks after the last dose.
- Speak with your doctor if you are pregnant or planning to become pregnant while taking topiramate.
Information for healthcare professionals
- Congenital malformations, neurodevelopmental disorders (autism spectrum disorders, intellectual disability, attention deficit hyperactivity disorder), and small for gestational age have been reported in babies and children following in utero topiramate exposure.
- Topiramate should be used to treat epilepsy in pregnancy only if the potential benefits justify the potential risks to the fetus.
- The use of topiramate for migraine prophylaxis is contraindicated in pregnancy and in women of childbearing potential not using highly effective contraception.
- Recommendations to limit exposure to topiramate during pregnancy are shown in Table 2.
Table 2: Recommendations to limit exposure to topiramate during pregnancy
| In all women of childbearing potential |
|---|
| Perform pregnancy testing before starting treatment with topiramate. |
| Inform them about the risks of fetal harm should they become pregnant. |
| A highly effective contraceptive method (such as an intrauterine device) or two complementary forms of contraception, including a barrier method, should be used during treatment with topiramate and for at least four weeks after stopping treatment. |
| At the next appointment for current users of topiramate, re-evaluate treatment to confirm that pregnancy prevention measures are adhered to. |
| Reassess the need for treatment with topiramate at least annually. |
| If a woman is planning to become pregnant: |
| Switch topiramate to an appropriate alternative before contraception is discontinued. |
| Inform women with epilepsy about the potential risks of uncontrolled seizures on pregnancy outcomes. |
| If a woman being treated with topiramate for epilepsy becomes pregnant |
| Promptly refer to a specialist to reassess topiramate treatment and possible alternative treatment options, as well as for careful antenatal monitoring and counselling. |
| If a woman being treated with topiramate for migraine prophylaxis becomes pregnant |
| Stop topiramate immediately and refer the woman to a specialist for antenatal monitoring and counselling. |
Sources: Topiramate data sheets, available at www.medsafe.govt.nz/Medicines/infoSearch.asp (accessed 16 September 2025).
Further information
There is an increased risk of congenital malformations if topiramate is taken during pregnancy. These include craniofacial defects (eg, cleft lip/palate), hypospadias and anomalies involving various body systems.
An increased risk of neurodevelopmental disorders, including attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and intellectual disability, was seen in observational studies:
- Two observational studies using similar datasets suggest there may be a two- to three-fold higher risk of ASD, intellectual disability or ADHD in almost 300 children born to mothers with epilepsy who took topiramate during pregnancy compared with children born to mothers with epilepsy who were not taking any antiepileptic medicines during pregnancy.3, 4
- On the other hand, an observational study in 1,030 children born to mothers with epilepsy who took topiramate during pregnancy did not show an increased risk of ASD compared with children born to mothers with epilepsy who were not taking antiepileptic medicines during pregnancy.5
Analysis of data from a pregnancy registry showed an increased frequency of infants who were small for gestational age when born to mothers who were taking topiramate during pregnancy. Small for gestational age has been observed at all doses of topiramate but the prevalence increases with higher doses. The prevalence is also higher for women who continue taking topiramate later in pregnancy compared to women who stop taking it before the third trimester.1, 2
New Zealand pharmaceutical dispensing data indicates that the use of topiramate during pregnancy has increased over the last 10 years, from more than 20 pregnant women dispensed topiramate during 2014 to more than 40 during 2023.
Useful links
- Topamax Dear Healthcare Professional Letter (PDF, 4 pages, 143KB)
- Topiramate Actavis Dear Healthcare Professional Letter (PDF, 7 pages, 848 KB)
- Epilepsy medicines and pregnancy consumer information leaflet
- Search for consumer medicine information (CMI) and data sheets
- Report an adverse reaction to a medicine (side effect)
References
- Janssen-Cilag (New Zealand) Ltd. 2025. Topamax New Zealand Data Sheet 3 March 2025. URL: www.medsafe.govt.nz/profs/Datasheet/t/topamaxtabcap.pdf (accessed 16 September 2025).
- Teva Pharma (New Zealand) Limited. 2025. Topiramate Actavis New Zealand Data Sheet 29 August 2025. URL: www.medsafe.govt.nz/profs/Datasheet/t/topiramateactavistab.pdf (accessed 16 September 2025).
- Bjørk M-H, Zoega H and Leinonen MK. 2022. Association of prenatal exposure to antiseizure medication with risk of autism and intellectual disability. JAMA Neurology 79(7): 672-81. DOI: 10.1001/jamaneurol.2022.1269 (accessed 18 August 2025).
- Dreier JW, Bjørk M-H and Alvestad S. 2023. Prenatal exposure to antiseizure medication and incidence of childhood- and adolescence-onset psychiatric disorders. JAMA Neurology 80(6): 568-77. DOI: 10.1001/jamaneurol.2023.0674 (accessed 18 August 2025).
- Hernández-Díaz S, Straub M, Bateman BT, et al. 2024. Risk of autism after prenatal topiramate, valproate, or lamotrigine exposure. New England Journal of Medicine 390(12): 1069-79. DOI: 10.1056/NEJMoa2309359 (accessed 18 August 2025).
