Is It Safe to Use Phenytoin in Pregnancy?

Many medications can carry risks for both mother and fetus when they are taken during pregnancy. Phenytoin, a medication that is often taken to prevent and treat epilepsy and other seizure disorders, can sometimes lead to birth defects and health problems when used in therapeutic doses. These defects are not certainties, and sometimes, women may derive a greater benefit from taking this medication that outweighs any potential risks. Generally, women taking this drug are advised to consult a medical professional when deciding whether or not to take phenytoin in pregnancy.

Several possible health issues could arise as a result of taking phenytoin in pregnancy. Depletion of some nutrients, like folate, vitamin D, and vitamin K, can occur when using this drug. Some women may experience a greater loss of these nutrients when pregnant. Prolonged shortages of these compounds can create secondary health problems, so women using phenytoin in pregnancy may opt to take supplemental doses of nutrients to prevent these issues. Additional vitamins may sometimes help to avoid deficiency issues in both women and their babies, and keep infants from having poor growth and low weight.

Overall, infants exposed to phenytoin in pregnancy seem to have an increased risk of birth defects, according to research compiled by the US Food and Drug Administration. Defects including heart problems and cleft lip or palate may occur in as many as four to seven percent of babies whose mothers took phenytoin in pregnancy. Ordinarily, the rate of these defects is around two to three percent, according to the same studies. Other minor defects like short fingers may occur as well, although these often become unnoticeable as the child matures.

Due to these risks, women may consider changing to medications other than phenytoin in pregnancy to control seizures, as seizures may harm the fetus, as well. Many other seizure medications may have around the same rate of risk for birth defects; consequently, women sometimes decide that using phenytoin while pregnant carries acceptable risks, but they may lower their dosage in order to reduce the chances of health issues arising. Changing the dosage of seizure medication may sometimes lead to its own set of possible dangers, however, so these women usually make this decision after consulting with a medical professional. Like many other drugs, this medication is not considered completely safe for use while pregnant, but there are actions that may be taken in order to bring the potential risks down to acceptable levels.