Diethylstilbestrol drug, molecular model. This drug is a synthetic nonsteroidal oestrogen first synthesised in 1938. It was used to treat postmenopausal symptoms, vaginitis (inflammation of the vaginal mucosa), prostate and advanced breast cancer. It was also thought to prevent miscarriages. However, it was found to be a teratogen, causing congenital defects when prescribed to pregnant women. Manufacture of the drug ceased in 1997. In this model, atoms are represented by coloured spheres; carbon is grey, hydrogen is white and oxygen is red.