Is topical tretinoin safe to use during pregnancy or when nursing?

Topical tretinoin is classified as a pregnancy category C drug, which means that a risk to the fetus cannot be ruled out. Prospective human studies are lacking, but studies on animals using doses up to 320 times those used in humans did not produce teratogenic effects. A retrospective British study on pregnant women who had received topical tretinoin did not demonstrate teratogenic effects. However, because high-dose (1000 times the topical human dose) oral tretinoin has been demonstrated to be teratogenic in rats, many dermatologists do not use this drug in pregnant women to avoid litigation in the event congenital abnormality occurs. Birth defects have been reported in rare patients receiving topical tretinoin or topical adapalene; however, it is unknown whether these birth defects were due to the topical retinoids. Because of the lack of data, it is probably prudent to not use topical retinoids in pregnant patients if possible. It is not known whether topical tretinoin is secreted in human milk, but the manufacturers recommend that caution be exercised when this drug is administered to nursing mothers.

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