Notes
- Category A: Adequate, well-controlled studies in pregnant women have not shown an increased risk of fetal abnormalities.
- Category B: (1) Animal studies show no adverse fetal effects, but there are no controlled human studies, or (2) animal studies show adverse fetal effect, but well-controlled human studies do not.
- Category C: (1) Animal studies show adverse fetal effect, but there are no controlled human studies, or (2) no animal or well-controlled human studies have been conducted.
- Category D: Well-controlled or observational human studies show positive evidence of human fetal risk. Maternal benefit may outweigh fetal risk in serious or life-threatening situations.
- Category X: Contraindicated. Well-controlled or observational human and/or animal studies show positive evidence of serious fetal abnormalities. Fetal risks far outweigh maternal benefit.