Benzoyl peroxide and tretinoin

8.1 Pregnancy Risk Summary Available data from published observational studies of topical tretinoin in pregnant women have not established a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Studies conducted with topical benzoyl peroxide have not demonstrated systemic absorption and maternal use is not expected to result in fetal exposure to benzoyl peroxide. There are no data on TWYNEO use in pregnant women.

There are reports of major birth defects reported with maternal use of topical tretinoin similar to those seen in infants exposed to oral retinoids, but these case reports do not establish a pattern or association with tretinoin-related embryopathy ( see Data ). Animal reproductive studies have not been conducted with TWYNEO or benzoyl peroxide.

Topical administration of tretinoin to pregnant rats during organogenesis was associated with malformations (craniofacial abnormalities [hydrocephaly], asymmetrical thyroids, variations in ossification, and increased supernumerary ribs) at doses greater than 1 mg tretinoin/kg/day, approximately 5 times the maximum recommended human dose (MRHD) based on body surface area (BSA) comparison and assuming 100% absorption. Oral administration of tretinoin to pregnant cynomolgus monkeys during organogenesis was associated with malformations at 10 mg/kg/day (approximately 100 times the MRHD based on BSA comparison and assuming 100% absorption) ( see Data ).

The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of major birth defects, loss and other adverse outcomes. The background risk in the U.S. general population of major birth defects is 2 to 4% of miscarriage is 15 to 20% of clinically recognized pregnancies. Data Human Data While available studies cannot definitively establish the absence of risk, published data from multiple prospective controlled observational studies on the use of topical tretinoin products during pregnancy have not identified an association with topical tretinoin and major birth defects or miscarriage.

The available studies have methodologic limitations, including small sample size and in some cases, lack of physical exam by an expert in birth defects. There are published case reports of infants exposed to topical tretinoin during the first trimester that describe major birth defects similar to those seen in infants exposed to oral retinoids; however, no pattern of malformations has been identified and no causal association has been established in these…