DES is an abbreviation for Diethylstilbestrol, a synthetic carcinogenic hormone drug that has been known to cause cancer in women exposed in-utero. It was first developed in 1938 and has since been marketed under hundreds of different brand names in the belief that it prevented premature deliveries and miscarriages. DES prescriptions were issued between 1938 and 1971, and it was considered the standard of care for problem pregnancies in the US during this period. In 1971 it was found to cause various health-related problems, including an increased risk of breast cancer, and the FDA told doctors to stop issuing DES prescriptions, though it has never been banned. There has never been a class action relating to DES, but many DES-exposed people have successfully sued drug companies that manufactured the drug.