Category A —
- Studies in pregnant women have not shown an increased risk of birth defects.
Category B —
- Animal studies have revealed no evidence of harm to the fetus. However, there are no adequate studies in pregnant women.ORAnimal studies have shown an adverse effect, but adequate studies in pregnant women have failed to show a risk to the fetus.
Category C —
- Animal studies have shown an adverse effect and there are no adequate studies in pregnant women.ORNo animal studies have been conducted or there are no adequate studies in pregnant women.
Category D —
- Adequate studies in pregnant women have demonstrated a risk to the fetus. However, the benefits of the drug may outweigh the potential risk.
Category X —
- Adequate studies in animals or pregnant women have shown evidence of birth defects. Women who are or may become pregnant should not use the drug.