FDA Prenancy Categories

Question 0

What is Category B?

Answer 0

Slightly more risk than A: Animal studies show no fetal risk, but controlled studies have not been done in women.
or
Animal studies do show a risk of fetal harm, but controlled studies in women have failed to demonstrate a risk during the first trimester, and there is no evidence of risk in later trimesters.

Question 1

What is Category A?

Answer 1

Remote risk of fetal harm: Controlled studies in women have been done and have failed to demonstrate a risk of fetal harm during the first trimester, and there is no evidence of risk in later trimesters.

Question 2

What is Category C?

Answer 2

Greater Risk than B: Animal studies show a risk of fetal harm, but no controlled studies have been done in women.
or
No studies have been done in women or animals.

Question 3

What is Category D?

Answer 3

Proven Risk of Fetal Harm: Studies in women show proof of fetal damage, but the potential benefits of use during pregnancy may be acceptable despite the risks (e.g.» treatment of life-threatening disease for which safer drugs are ineffective) A statement on risk will appear in the “WARNINGS” section of drug labeling.

Question 4

What is Category X?

Answer 4

Proven Risk of Fetal Harm: Studies in women or animals show definite risk of fetal abnormality.
or
Adverse reaction reports indicate evidence of fetal risk. The risks clearly outweigh any possible benefit. A statement on risk will appear in the “CONTRAINDICATIONS” section of drug labeling.