Findings of the Epilepsy Birth Control Registry

Herzog AG, Mandle HB, Cahil KE, Fowler KM, Hause WA. Epilepsy & Behavior 60 (2016);112-117.

Purpose

People often wonder if birth control or contraception may affect seizure control in women with epilepsy. Information about whether different forms of contraception help or worsen seizures is lacking. The Epilepsy Birth Control Registry (EBCR) is intended to help learn what women with epilepsy use for contraception and how it may affect them.

Description of study

The EBCR is a web-based survey study of women with epilepsy in the community. Women participate voluntarily and give information about experiences with contraception, seizures, seizure medications, and other relevant information. To be part of the EBCR, women must be between 18 and 47 years old and be diagnosed with epilepsy.

  • 1,144 women with epilepsy in the EBCR reported information on 2,712 contraceptives used (this was called “contraceptive experiences” in the article)
  • Types of contraception included
    • Systemic hormonal forms (pills, patches, vaginal rings, implants, or injections) of a combined hormone (estrogen and progesterone combination) or a form of progestin only
    • Nonhormonal methods – withdrawal, condoms, intrauterine devices (IUD), and tubal ligation
  • Information about seizure control was obtained from how women answered the following question, “Do you think that this method of birth control changed how often you had seizures?”

A summary of study findings

  • Most women did not report any change in seizures when using contraception or birth control.
  • 30.7% of the women with epilepsy who tried one or more contraceptive methods reported a change in seizure control.
  • When changes in seizures were noted, 28.2% were using a hormonal form of birth control while 9.7% used a nonhormonal form. This means the relative risk for a change in seizures was higher for women taking a hormonal form of contraception. Interestingly, the likelihood for a decrease in seizures while on birth control was greater in women taking a hormonal form (9.5%) as compared to those with nonhormonal forms of birth control (5.5%).
  • The types of contraception with the lowest reported rates of seizure increase were barrier methods such as condoms. Systemic hormonal methods had the highest rates of seizure increase, particularly with a hormonal patch or progestin only pill.
  • The risks for seizure increase were higher when taking hormonal forms of birth control, regardless of the type of seizure medication used. Seizure medicines that did not affect liver enzymes (called non-enzyme-inducing AEDs) had the lowest chance of increasing seizures.

What does this mean?

  • Most women who use birth control do not report changes in seizures, either an increase or decrease.
  • Certain types of seizure medications, especially those that affect liver enzymes, may affect the chance of changes in seizure control for some women.
  • All girls and women with epilepsy should talk to their health care providers and learn about types of birth control and what may be best for them. Since medicines may change over time, birth control should be reviewed regularly with your health care team.
  • Women with epilepsy who notice a worsening of seizures while using birth control should track this and ask if a change in birth control or seizure medication may be needed.

Article published in Epilepsy & Behavior, July 2016

Authored By: 
Patty Obsorne Shafer RN, MN
Authored Date: 
08/2016
Reviewed By: 
Christianne N. Heck MD, MMM
on: 
Tuesday, August 2, 2016