Diethylstilbestrol is a synthetic non-steroidal estrogen that was widely used in the past to prevent potential miscarriages by stimulating the synthesis of estrogen and progesterone in the placenta (in the United States of America, especially from the 1940s to the 1970s). It was also used in the treatment of  menopausal and  postmenopausal disorders. According to IARC , there is sufficient evidence in humans for the carcinogenicity of diethylstilbestrol.