Tretinoin

Pregnancy

This entry covers topical tretinoin, not oral tretinoin or oral isotretinoin. MotherToBaby reports that studies of correct topical use have not found a higher chance of birth defects, but its fact sheet does not give counts for those studies. It also says topical use is not expected to increase miscarriage and notes that case reports do not establish cause. The Altreno label, published October 6, 2026, says observational studies of topical tretinoin have not established a drug-associated risk of major birth defects or miscarriage, but there are no pregnancy data for Altreno itself. Kaplan et al. (2015) reviewed 654 exposed and 1,375 unexposed pregnancies. It found no significant increase in major congenital malformations (OR 1.22; 95% CI 0.65 to 2.29), spontaneous abortion (OR 1.02; 95% CI 0.64 to 1.63), or prematurity (OR 0.69; 95% CI 0.39 to 1.23). The authors said statistical power was not adequate to justify topical retinoid use during pregnancy. Refsum et al. (2026) used Nordic registry data on infants born at 22 weeks or later after first-trimester exposure to topical retinoids. Major malformations were recorded in 71 of 2,172 exposed infants (3.3%) and 111,404 of 3,671,023 unexposed infants (3.0%); the adjusted risk ratio was 1.1 (95% CI 0.87 to 1.38). The study grouped topical retinoids and did not report tretinoin separately. It included births only, which the authors said could underestimate exposure and risk. Alali et al. (2026) reviewed 8 studies with 3,632,118 pregnancies and found no significant association for major congenital malformations (RR 0.83; 95% CI 0.64 to 1.07) or spontaneous abortion (RR 0.99; 95% CI 0.68 to 1.43) after first-trimester topical retinoid exposure. The authors noted that the result was driven mainly by one large registry study. The second- and third-trimester comparisons in MotherToBaby were not supported by a direct later-trimester risk estimate in the reviewed primary studies.

Breastfeeding

LactMed, revised October 15, 2024, says topical tretinoin is poorly absorbed and considered low risk for a nursing infant, but it reports no published data on drug levels in milk or effects in breastfed infants. MotherToBaby says breastfeeding use has not been studied and that the amount in milk would probably be small because little tretinoin passes into the body after skin use. The Altreno label, published October 6, 2026, also reports no data on tretinoin or its metabolites in human milk, effects on the breastfed infant, or effects on milk production. NHS SPS gives general guidance that topical routes lead to lower breast-milk levels than systemic routes; it does not provide tretinoin-specific evidence. No primary study measuring tretinoin in human milk or reporting infant outcomes was identified.

What was tested

The human pregnancy evidence reviewed here includes observational studies, a systematic review and meta-analysis, and Nordic registry data. The 2015 and 2026 reviews cover topical retinoids as a group, rather than a single tretinoin brand. The Nordic cohort assesses first-trimester exposure and includes infants born at 22 weeks or later; it does not estimate outcomes for pregnancies ending earlier or separate tretinoin from other topical retinoids. The Altreno label states that animal reproduction studies were not conducted with Altreno itself. Human breastfeeding evidence is absent in the reviewed sources: no milk-level or infant-outcome study was identified.