Topiramate and Risk of Birth Defects: New Data for Women with Epilepsy

Epilepsy News From: Friday, April 13, 2018

Topiramate use early in pregnancy and the risk of oral clefts: A pregnancy cohort study. Hernandez-Diaz S, Huybrechts KF, Desai RJ, et al. Neurology 90(2018): 342-351.


  • Topiramate (brand name Topamax in the U.S., Canada, the UK, and Australia) is a commonly used medication. It was developed as an anti-seizure medication, but it is prescribed more frequently for other conditions including migraine prevention and treatment of bipolar disorder.
  • Prior studies have indicated a 2- to 5-fold increase in the risk of cleft lip or cleft palate in infants born to mothers who used topiramate in early pregnancy. No distinction was made between women who took topiramate for epilepsy versus those who took it for other reasons.
  • A recent study by researchers at Harvard medical school looks at that difference.

New Findings

The 2018 study found that oral clefts (lip or palate) occurred with the following frequencies in different groups.

No topiramate (control group)

  • Average dose of topiramate per day: not applicable
  • Number of oral clefts per 1,000 births: 1.1

Topiramate for other indications

  • Average dose of topiramate per day: 100 mg
  • Number of oral clefts per 1,000 births: 2.1

Topiramate for epilepsy

  • Average dose of topiramate per day: 200 mg
  • Number of oral clefts per 1,000 births: 12.3


  • Topiramate taken for any reason during early pregnancy increases the risk of having an infant with cleft lip or palate.
  • Importantly, the risk is higher in women who take topiramate specifically to treat epilepsy.
  • The higher risk is likely due to higher doses used to treat epilepsy compared to doses used for other indications.

Talk to your doctor about the potential risks associated with different seizure medications before you get pregnant!

Authored by

Kristine Ziemba MD, PhD

Reviewed Date

Friday, April 13, 2018

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