When Susan Manning, a 39-year-old woman just a few weeks into her first pregnancy, wrote to tell me she had been put on the steroid dexamethasone to prevent a miscarriage–and to ask whether she should be worried about taking this drug–at first I could not even process what she was saying. Dexamethasone is known to cross the placental barrier and impact fetal development, so the very idea of first trimester exposure sets off warning bells. Besides, dexamethasone is not known to help in preventing miscarriage. Susan’s story sounded too crazy to be true.
It also sounded too close to the history of DES (diethylstilbestrol). From the 1940s through the 1970s, some doctors gave pregnant women DES, a synthetic estrogen, to try to prevent miscarriage. In spite of clinical evidence that it didn’t work as intended, millions of fetuses were exposed in utero before doctors discovered that prenatal DES exposure could lead to infertility and deadly cancers. Just last week, Eli Lilly & Co. settled a suit brought by four sisters who believe their breast cancers were caused by prenatal DES exposure. Read full article.