Pregnancy Category
A classification system indicating the risk of using a drug during pregnancy based on available evidence. While the FDA phased out letter categories (A, B, C, D, X) in 2015 in favour of narrative labelling, the categories remain commonly referenced. Most peptide drugs affecting hormonal systems are contraindicated in pregnancy.
Technical Context
Legacy FDA categories (phased out 2015, replaced by narrative labelling under the Pregnancy and Lactation Labelling Rule/PLLR): Category A (adequate human studies show no risk), B (animal studies no risk + no adequate human studies), C (animal studies show risk + no adequate human studies OR no studies in either), D (evidence of human risk but benefits may justify use), X (evidence of human/animal risk, risks clearly outweigh benefits — CONTRAINDICATED). Under PLLR (effective June 2015 for new drugs), labels include: Pregnancy subsection (risk summary, clinical considerations, data), Lactation subsection (risk summary, clinical considerations, data), and Females/Males of Reproductive Potential subsection (contraception requirements, fertility effects). Most peptide drugs affecting hormonal systems are contraindicated in pregnancy. GLP-1 RAs recommend discontinuing at least 2 months before planned pregnancy (based on semaglutide's ~5-week half-life requiring ~5 half-lives for washout).