Reproductive Toxicity
The potential of a drug to adversely affect fertility, embryo-foetal development, or postnatal development. Reproductive toxicity studies in animals are required before a peptide drug can be used in women of childbearing potential. Many peptide drugs are contraindicated in pregnancy.
Technical Context
ICH S5(R3) reproductive toxicity studies: Segment I — fertility and early embryonic development (assessing effects on male/female fertility, mating behaviour, conception, and pre-implantation/early post-implantation development); Segment II — embryo-foetal development (EFD, assessing teratogenicity — structural abnormalities in offspring when dosed during organogenesis); Segment III — peri/postnatal development (PPND, assessing effects on late pregnancy, parturition, lactation, and offspring development). For GnRH agonists/antagonists, reproductive toxicity is expected based on the mechanism (suppressing sex hormones disrupts fertility and embryo-foetal development) — they carry pregnancy Category X classification. GLP-1 RAs: animal EFD studies showed embryo-foetal effects at high doses; pregnancy is listed as a contraindication or precaution. Women of childbearing potential are advised to use contraception during treatment and for a washout period after discontinuation.