The U.S Food and Drug Administration (FDA) has established pregnancy drug category labels for prescription drugs. There are 5 “Use-in-Pregnancy” categories (A, B, C, D, and X) where A is the least risk, and X is the highest.
Discuss your options with your obstetrician before using any medicine. Besides drugs, you should also discuss with your doctor the following treatments which are not categorized into a pregnancy drug category by the FDA:
herbal cures or alternative medicine: don’t assume that natural, herbal, or dietary supplements are safe for your baby.
over-the-counter creams, cleansers, treatments: some creams can be absorbed into the bloodstream.
The following pregnancy drug category chart is based on studies performed on humans and animals. The categories reflect the degrees of potential drug benefits outweighing the risks to the fetus. In category X, the risk to the fetus is too great to outweigh any drug benefits to the mother.
Pregnancy Drug Category Chart
No risk. Studies in pregnant women have not shown a risk to the fetus in any trimester of pregnancy.
Remote risk. Animal studies show no evidence of risk to the fetus, but there are no adequate studies in pregnant women.
Animal studies show an adverse effect, but studies in pregnant women have failed to show a risk to the fetus in any trimester.
Category B includes: azelaic acid, oral and topical erythromycin, oral and topical clindamycin, metronidazole.
Possible risk. Animal studies have shown an adverse effect and there are no adequate studies in pregnant women. OR
No animal studies have been conducted and there are no adequate studies in pregnant women.
Doctors do not recommend category C during pregnancy.
Category C includes: adapalene, benzoyl peroxide, antibiotic-penzoyl peroxide combinations, sodium sulfacetimide, tretinoin, dapsone, spironolactone, and oral corticosteroids.
Definite evidence of risk. Adequate well-controlled or observational studies in pregnant women show a risk to the fetus.
These drugs would rarely be used during pregnancy.
For instance, the drug may be acceptable in a life-threatening situation when safer drugs are unavailable.
Category D includes: doxycline, minocycline, tetracycline, flutamide.
Not to be used in pregnancy. Studies in animals or pregnant women show positive evidence of fetal abnormalities or risks.
The use of the product is contraindicated in women who are or may become pregnant.
Category X includes: isotretinoin (Accutane), tazarotene.
Sources: FDA Consumer magazine Volume 35, Number 3 May-June 2001, Preston, Lydia. Breaking Out. New York: Fireside, 2004.