[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Embryology](https://durgical.com/en/embryology/) › [Teratology and prenatal diagnosis](https://durgical.com/en/embryology/#a-teratology) › Androgens, diethylstilbestrol and other hormones [Embryology](https://durgical.com/en/embryology/) · [Teratology and prenatal diagnosis](https://durgical.com/en/embryology/#a-teratology) # Androgens, diethylstilbestrol and other hormones - Teratogen Sex hormones that reach the fetus can change the shape of the genitals and reproductive tract; the historical case is DES. Updated 2026-11-01 **See it in 3D:** [Clitoris](https://durgical.com/en/anatomy/clitoris/) · [Labia majora](https://durgical.com/en/anatomy/labium-majus-of-vulva/) · [Vagina](https://durgical.com/en/anatomy/vagina/) · [Cervix](https://durgical.com/en/anatomy/cervix-of-uterus/) · [Body of uterus](https://durgical.com/en/anatomy/body-of-uterus/) · [Epididymis](https://durgical.com/en/anatomy/epididymis/) ## Key points - Androgens before the end of the first trimester: clitoromegaly and labioscrotal fusion in 46,XX fetuses. - After that period androgens only enlarge the clitoris, because the folds no longer fuse. - DES-exposed daughters: clear cell adenocarcinoma of the vagina and cervix (rare), T-shaped uterus and Müllerian duct anomalies. - DES daughters: more infertility, ectopic pregnancy, preterm birth and second-trimester miscarriage. - DES-exposed sons: cryptorchidism and epididymal cysts. ## What it is The genitals and reproductive ducts differentiate according to the hormones present in the first trimester. External androgens (or older progestins with androgenic effects) virilize the genitals of a 46,XX fetus. Diethylstilbestrol (DES), a synthetic oestrogen used from 1940 to 1971 to prevent miscarriage, left reproductive tract malformations and a rare cancer in exposed daughters: the classic example of a teratogen whose effects show years later. ## Key facts - DES was used from 1940 to 1971; in 1971 it was linked to clear cell adenocarcinoma. - Exposed daughters have about 40 times the risk of that cancer, though it remains rare. - Endogenous androgen sources: fetal congenital adrenal hyperplasia and virilizing maternal tumours. - Oral contraceptives have a low teratogenic potential. - Environmental endocrine disruptors act on hormone receptors and are studied for reproductive tract effects. ## Critical period and mechanism - Critical period: first trimester, while the genital ducts and external genitalia differentiate. - Androgens activate their receptors in the genital tubercle and folds and masculinize them even in a 46,XX fetus. - DES crosses the placenta, binds sex hormone–binding globulin poorly and is converted to reactive metabolites. - It disturbs differentiation of the Müllerian ducts (uterus, tubes and upper vagina). ## Prevention - Avoiding androgenic hormones in pregnancy unless the treating professional indicates them. - Women exposed to DES in the womb receive regular gynaecological follow-up. - Medicines in pregnancy are decided with the treating professional. ## What it does to the embryo and fetus - Ambiguous genitalia in a 46,XX fetus: large clitoris and fused labia. - T-shaped uterus, abnormal cervix or vagina, vaginal adenosis. - Clear cell adenocarcinoma in young exposed women. - Cryptorchidism and epididymal cysts in exposed males. ## Memory aid 'Early androgen welds the labia, late androgen only enlarges the clitoris'; DES 'leaves a T-shaped mark'. ## Test yourself Think of the answer, then tap the question to see it. ## What do androgens do to a 46,XX fetus exposed in the first trimester? They virilize the external genitalia: clitoromegaly and fusion of the labioscrotal folds. ## Which cancer is linked to in-utero DES exposure? Clear cell adenocarcinoma of the vagina and cervix. ## Which embryonic structures does DES disturb in exposed women? The Müllerian duct derivatives: uterus (T-shaped uterus), tubes, cervix and upper vagina. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/embryology/androgens-diethylstilbestrol-and-other-hormones/) ## See it in 3D The structures of Durgical's 3D anatomy where it is found. - [Clitoris](https://durgical.com/en/anatomy/clitoris/) - [Labia majora](https://durgical.com/en/anatomy/labium-majus-of-vulva/) - [Vagina](https://durgical.com/en/anatomy/vagina/) - [Cervix](https://durgical.com/en/anatomy/cervix-of-uterus/) - [Body of uterus](https://durgical.com/en/anatomy/body-of-uterus/) - [Epididymis](https://durgical.com/en/anatomy/epididymis/) ## Related - [Differences of sex development: CAH, AIS and 5α-reductase](https://durgical.com/en/embryology/differences-of-sex-development-cah-ais-and-5-reductase/) - [External genitalia and their male–female homologues](https://durgical.com/en/embryology/external-genitalia-and-their-male-female-homologues/) - [Genital ducts: Wolffian (mesonephric) and Müllerian (paramesonephric)](https://durgical.com/en/embryology/genital-ducts-wolffian-and-mullerian/) - [Uterine anomalies: bicornuate, septate, didelphys, Müllerian agenesis](https://durgical.com/en/embryology/uterine-anomalies-bicornuate-septate-didelphys-mullerian-agenesis/) - [Cryptorchidism](https://durgical.com/en/embryology/cryptorchidism/) - [Sex determination: SRY, anti-Müllerian hormone and testosterone](https://durgical.com/en/embryology/sex-determination-sry-anti-mullerian-hormone-and-testosterone/) ## Related conditions - [Congenital adrenal hyperplasia due to 21-hydroxylase deficiency](https://durgical.com/en/conditions/congenital-adrenal-hyperplasia-due-to-21-hydroxylase-deficiency/) - [Cryptorchidism (undescended testis)](https://durgical.com/en/conditions/cryptorchidism/) - [Ectopic pregnancy](https://durgical.com/en/conditions/ectopic-pregnancy/) - [Preterm labour and birth](https://durgical.com/en/conditions/preterm-labour-and-birth/) [← All of embryology](https://durgical.com/en/embryology/) Educational content on embryonic development; not a guide to prenatal diagnosis or to medicines in pregnancy and no substitute for a health professional's advice. No doses are given. Sources: [Diethylstilbestrol (DES) Exposure and Cancer](https://www.cancer.gov/about-cancer/causes-prevention/risk/hormones/des-fact-sheet) (National Cancer Institute, 2021); [Teratogenic Medications](https://www.ncbi.nlm.nih.gov/books/NBK553086/) (StatPearls Publishing (NCBI Bookshelf), 2024); Langman's Medical Embryology, 13th ed., ch. 9: Birth Defects and Prenatal Diagnosis (Wolters Kluwer, 2015). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/embryology/androgens-diethylstilbestrol-and-other-hormones/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/embryology/androgens-diethylstilbestrol-and-other-hormones/