diethylstilbestrol

:  a synthetic estrogen drug C₁₈H₂₀O₂ used formerly to prevent miscarriage or premature delivery in humans and to promote growth in livestock—called also DES, stilbestrol ◆The medical use of diethystilbestrol was discontinued in the U.S. during the early 1970s due to its association with serious side effects (such as reproductive tract abnormalities and increased rates of infertility) in offspring exposed to the drug while developing in the uterus. Additional side effects of exposure include increased risk of adenocarcinoma of the vagina and cervix and pregnancy complications in female offspring and prostate and testicular cancer in male offspring. Diethylstilbestrol is no longer commercially available in the U.S. and its use is currently limited to specially compounded formulations for veterinary care.