FDA Pregnancy Drug Classes
The FDA assigns drugs to one of five pregnancy classes. These class are used to help families and doctors weigh the risks and benefits of taking a medication during pregnancy. Many drugs are considered to be teratogens; teratogens are known to harm the embryo/fetus. A teratogen can do many things including causing the pregnancy to stop or causing birth defects. Some drugs that may cause birth defects include Accutane, Paxil, Prozac and other SSRIs. Following are descriptions of the pregnancy drug classes.
Category A
Controlled studies in women do not demonstrate a risk to the fetus. The possibility of fetal harm appears remote.
Category B
Either animal studies have not demonstrated a fetal risk but there are no controlled studies in pregnant women, or animal studies have shown an adverse effect that was not confirmed in controlled studies in women.
Category C
Either studies in animals have revealed adverse effects on the fetus and there are no controlled studies in women, or studies in women and animals are not available. Drugs in category C should only be taken if the benefit justifies the fetal risk.
Category D
There is positive evidence of human fetal risk (birth defects, etc.), but the benefits from use in pregnant women may be acceptable despite the risk.
Category X
Studies in animals or human beings have demonstrated fetal abnormalities or there is evidence of fetal risk based on human experience, and the risk of the use of the drug in pregnant women clearly outweighs any possible benefit. Drugs in category x should not be taken by pregnant women for any reason.
