pregnancy test

Are women with epilepsy at higher risk for unintended pregnancies?

A recent study by Dr. Andrew Herzog and colleagues suggests that the answer is yes.

Study Design

  • Data were collected from a web-based survey of women with epilepsy (WWE), the Epilepsy Birth Control Registry (EBCR).
  • A total of 1,144 WWE between ages 18 and 47 years were included in this review between 2010 and 2014. Of these, 437 women reported getting pregnant after being diagnosed with epilepsy.
  • Information collected included:
    • Demographics: age, race, ethnicity, education, household income, health insurance, and geographic location
    • Type of epilepsy or seizures: generalized convulsive (tonic-clonic), complex partial (focal impaired awareness), or simple partial (focal aware)
    • Antiepileptic drug(s) (AEDs) used.
    • Type of contraception (birth control): None, withdrawal, barrier (condom, diaphragm), systemic hormonal (oral contraceptive pill or patch, implanted progestin, or depomedroxyprogesterone acetate shots), intrauterine device (IUD), tubal ligation, or partner with vasectomy.
    • Pregnancy intended or unintended


  • A total of 345 (78.9%) of the 437 WWE reported having at least one unintended pregnancy. A total of 523 of 804 pregnancies (65%) in those women were identified as unintended.
  • WWE with only generalized convulsions were at greater risk of unintended pregnancy as compared to WWE who had a history of only partial (focal) seizures.
  • Women using oral hormonal contraceptives (“the pill”) with seizure medications (AEDs) classified as “enzyme-inducing” drugs (phenobarbital, phenytoin, carbamazepine, oxcarbazepine, and topiramate at doses of 200 mg daily or more) were at highest risk for unintended pregnancy.
  • Among reversible types of birth control, the IUD had the lowest rate of unintended pregnancy in this population (3.1%).
  • No unintended pregnancies were reported among women with non-reversible contraception (tubal ligation or partners with vasectomy).


  • Compared with the general population in the U.S., WWE appear to be at higher risk for unintended pregnancies (78.9% of WWE vs 45-51% in the general population).
  • Different types of birth control and seizure medication pose different risks for unplanned pregnancy.
  • It is very important for women of childbearing potential with epilepsy to talk to their doctors about contraception and family planning to prevent unintended pregnancies! This discussion must include the type of medicine she takes and how this would affect her choice of contraception.


Predictors of unintended pregnancy in women with epilepsy
Andrew G. Herzog, Hannah B. Mandle, Kaitlyn E. Cahill, Kristen M. Fowler, and W. Allen Hauser. February 21, 2017, Neurology 88:8 728-733; published ahead of print January 25, 2017, doi:10.1212/WNL.0000000000003637: 1526-632X.

Authored By: 
Kristine Ziemba MD, PhD
Authored Date: 
Reviewed By: 
Joseph I. Sirven MD
Tuesday, June 27, 2017