Levetiracetam is often used as a treatment for epilepsy, and it is usually taken with a few other anti-seizure medications for the best results. For this reason, it is not usually considered the best medication for pregnant women, who are typically advised to take only a single pill when possible. On the other hand, when no other medication is available, taking levetiracetam in pregnancy is generally considered safe because it can help avoid the risks that seizures pose to pregnant women. It is classified as a Pregnancy Category C drug by the U.S. Food and Drug Administration (FDA), because animal studies have shown negative effects for fetuses whose mothers take levetiracetam in pregnancy.
When researchers studied levetiracetam in pregnancy among rats in a laboratory, they found that one of the most common medical problems was slow growth in the baby, both in the womb and after the birth. In addition, some fetuses exhibited abnormalities in their skeletal development. These studies were typically performed using the highest recommended dose for humans, and they were mostly done early in the pregnancy. Studies performed in the third trimester, as well as in nursing rats, showed no medical problems for the babies or the mothers. These studies provide evidence that levetiracetam in pregnancy can be mildly harmful, particularly when taken in the first trimester, though it should be noted that animals do not always react to medication as humans would.
Some animal studies looking at the role of levetiracetam in pregnancy involved administering rather high doses of the drug to rats. The result was often the death of the fetus. When the drug was given to rabbits in high doses, some had miscarriages, while many of the fetuses that survived suffered from birth defects or low birth weight. In some cases, the mother was even adversely affected by the drug in high doses.
There are no properly controlled studies on human fetuses, which is why pregnant women are cautioned to take this drug only when the benefits outweigh the potential risks. There have, however, been some reports of women taking the drug throughout pregnancy and going on to deliver healthy babies without incident, which is why some doctors may still prescribe it when nothing else works. This medication is usually transferred into breast milk, though some studies show it does not stay in the body of breastfed babies for very long. Nonetheless, nursing mothers are often advised to discontinue breastfeeding if they need to take levetiracetam.