DES information

[PattiDESAction]

Diethylstilbestrol (DES) is a drug prescribed to prevent miscarriage, and also for problem pregnancies in general, primarily between 1938 and 1971 – but not limited to those years. It is a synthetic estrogen and caused health problems for the mothers who were given the drug (breast cancer) and for the children they were carrying. Known health issues for DES Daughters include clear cell adenocarcinoma (cancer) of the vagina and cervix – which is very rare, as well as breast cancer and infertility – among other reproductive tract problems. DES Sons may have experienced underdeveloped or undescended testicles. Some DES Sons were born with microphallus (micropenis). This has no impact of fertility, although it can have psycho-social significance. DES Sons also often suffer from epididymal cysts.

Over the years one of the most perplexing concerns expressed in the DES community has been whether DES exposure affected the neurological system and sexual differentiation. One 1983 study stated that, “sex hormones are known to have effects on the organization of the brain in experimental animals with consequential behavioral effects.”

It does appear that DES did reach the fetal brain in these animals. In an ordinary human pregnancy, the mother’s estrogen does not reach the fetal brain. We do not know if DES did reach the brain and, if it did, whether it could influence brain development. There may be protective factors in humans so that DES would not have the same effects as it has shown in lower mammals.

We have seen reports on animal models that similar endocrine disrupting estrogens can significantly alter the normal biological process of sex and gender differentiation in the brain. Perhaps DES also has had these effects in humans?

However, an article from the Journal of Epidemiology on psychosexual characteristics of DES Daughters and Sons has data from a large National Cancer Institute study that shows 95% of the subjects, male and female, reported exclusively heterosexual partners. There were no reports of AIS being linked to DES exposure, however, it is possible the cohorts, though large, were not large enough to tease it out. Also, growing fetuses are exposed to many environmental chemicals these days, making it difficult to precisely determine cause and effect for any particular one.

Without a doubt, more research is needed. At this time we cannot say whether DES exposure has any involvement with AIS. We just don’t know. So we conclude with what a scientist once wrote, “Absence of evidence is not evidence of absence.”