Definitions and management strategies from the US Food and Drug Administration categories for drugs taken during pregnancy
| CATEGORY | DEFINITION | MANAGEMENT STRATEGY |
|---|---|---|
| A | Adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus in the first trimester of pregnancy. | Because studies are not able to rule out the possibility of harm, (name of drug) should be used during pregnancy only if clearly indicated. |
| B | Animal reproduction studies have failed to demonstrate a risk to the fetus, but there are no adequate and well-controlled studies of pregnant women. Or animal studies demonstrate a risk, and adequate and well-controlled studies in pregnant women have not been done during the first trimester. | Because the studies of humans cannot rule out the possibility of harm, (name of drug) should be used during pregnancy only if clearly needed. |
| C | Animal reproduction studies have shown an adverse effect on the fetus, but there are no adequate and well-controlled studies of humans. The benefits from the use of the drug in pregnant women might be acceptable despite its potential risks. Or animal studies have not been conducted and there are no adequate and well-controlled studies of humans. | (Name of drug) should be given to pregnant women only if clearly needed. |
| D | There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies of humans, but the potential benefits from the use of the drug in pregnant women might be acceptable despite its potential risks. | If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus. |
| X | Studies in animals or humans have demonstrated fetal abnormalities or there is positive evidence of fetal risk based on adverse reaction reports from investigational or marketing experience, or both. The risk involved in the use of the drug in pregnant women clearly outweighs any possible benefits. | (Name of drug) is contraindicated in women who are or might become pregnant. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus. |