Study Finds Safer Antiseizure Medications for Pregnant Women With Epilepsy

The medications were found to carry lower congenital malformation risk.

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Over one million women of childbearing age are living with epilepsy in the U.S. If they become pregnant, managing the neurological disorder during pregnancy will be a delicate balancing act.

While remaining on antiseizure medications is crucial to prevent potentially life-threatening seizures for both mother and child, many of these drugs increase the risk of birth defects.

However, a new study offers reassuring news—three popular antiseizure medications have emerged as relatively safer options, causing fewer cases of congenital malformations in babies.

Levetiracetam, oxcarbazepine, and lamotrigine reported the lowest prevalence rates, providing some peace of mind to women who must continue treatment during this critical period.

Antiseizure Drugs Are a Necessary Risk

Seizures can endanger the fetus by slowing down the fetal heart rate and decreasing its oxygen supply. Seizures can also induce preterm labor in pregnant women, resulting in premature birth. Furthermore, potential trauma to the mother caused by a seizure, such as a fall, could lead to injury to the fetus.

Due to the risk of harm to the fetus, many doctors recommend that women with epilepsy remain on antiseizure medications during pregnancy, despite the risks.

Each year, around 20,000 babies are born to women living with epilepsy. A fetus is exposed to antiseizure medications in one out of every fifty pregnancies, according to the Epilepsy Foundation.

Since most women with epilepsy need to continue antiseizure medication during pregnancy, identifying the safest treatment options for these women is essential, the research team wrote in a paper published in JAMA Neurology.

What the Researchers Found

The research team analyzed nearly 10,000 pregnancies in which the embryos were exposed to different antiseizure medications. Congenital malformations were assessed during the first year of each child’s life. They found that the overall prevalence of major congenital malformations has decreased significantly—by 39 percent overall.

Specifically, the rate decreased by 6.1 percent between 1998 and 2004, 5.1 percent between 2005 and 2009, 4 percent between 2010 and 2014, and another 3.7 percent between 2015 and 2022.

The study results indicate that congenital malformations occurred in 2.5 percent of babies whose mothers took levetiracetam, 2.9 percent of those whose mothers took oxcarbazepine, and 3.1 percent of those whose mothers took lamotrigine.

The prevalence of congenital malformations was significantly higher for babies whose mothers took phenytoin, valproate, carbamazepine, or phenobarbital. The malformations were dose-dependent—the higher the dose of medication, the higher the risk of malformation.

Cardiac malformations were the most common occurrence in babies born with congenital malformations, the research team found, particularly after exposure to phenytoin, phenobarbital, topiramate, and valproate. Valproate was also associated with neural tube defects and hypospadias, a condition affecting the urethra in boys.

Women with epilepsy who are considering becoming pregnant should consult with their health care professionals, including a neurologist, to discuss the best way to manage epilepsy during pregnancy, the research team noted.