Did Diethylstilbestrol cause intersexed development in the DES Sons by blocking testicular testosterone production ?
This blog post was originally a comment made by a DES Son
“My own opinion is that DES caused intersexed development in the DES sons by blocking testicular testosterone production. DES is a potent chemical castration agent that for many years the treatment of choice for hormone-sensitive prostate cancer. Just 3mg of DES per day is enough to fully chemically castrate an adult man; the starting dose as a miscarriage treatment was 5mg per day (and often went much higher during the later stages of the pregnancy). It’s a not widely appreciated fact, but male development isn’t driven directly by genes, but instead by hormones (primarily testosterone) produced in the testicles of a male fetus. Given the ability DES has to block testosterone production, it’s no surprise that many DES sons are physically and/or psychologically intersexed. The surprising thing is that there’s so little public awareness of it!
If the problem is just one of testosterone production being suppressed during the critical time sexual development was taking place, then I don’t see any reason for there to be any long term genetic effect or 3rd generation effects. However, one thought that’s occured to me is that DES daughters often have a great deal of difficulty getting pregnant and carrying the pregnancy to term, which puts them at vastly increased risk of medical intervention – and potentially being given hormonal medication during the pregnancy. If one of these hormonal treatments for miscarriage (DES) can cause problems with intersexed development, then the likelihood is that others can too. There’s one drug in particular called hydroxyprogesterone caproate, which is in widespread current use to prevent miscarriages and premature births, and is being given in doses which I’m sure would have some serious gender-bending effects if you were to give the same dose to an adult man.
In short, although DES was phased out 40 years ago, there’s plenty of other sex hormone derivatives still finding their way inside pregnant women and potentially causing many of the same problems. That’s why I’ve been trying so hard to get people to take me seriously, and see whether there’s a link between exposure to these drugs before birth and endocrine and intersex-related problems later in life!”
Hugh Easton, 28/04/2013.