DES Sons

Males Whose Mothers Were Prescribed DES While Pregnant With Them

Health consequences for DES Sons are less well understood than those of DES Daughters, however DES Sons should remain aware of this exposure as part of their health histories. Most medical problems for DES Sons involve genital organs, with issues ranging from harmless irregularities to problems that may require medical treatment. Unfortunately, many people, including a large number of doctors, do not know that men can be affected by DES exposure before birth.

DES Sons INFO is a fact sheet to assist DES Sons in communicating their concerns. It can be printed and shared with health care providers.

Risks for adverse impacts have been found to be highest for men exposed to DES before the 11th week of gestation and whose mothers had been given the large cumulative dose of more than five grams of DES during pregnancy. A review of DES Son’s research explains why different studies have yielded conflicting results.


Health Effects

  • Cryptorchidism
    DES has been associated with extremely small testes and/or undescended testes (cryptorchidism). Men born with undescended testicles (even if their mother was not given DES) have an increased risk for developing testicular cancer. When found early, testicular cancer can generally be cured. All men should practice testicular self-exam regularly.
  • Epididymal Cysts
    Epididymal cysts are the most common abnormality in DES Sons. Cysts (fluid filled sacs) on the epididymis are benign (non-cancerous) growths that feel like small lumps. They are usually painless but can occasionally be painful, depending on location. Epididymal cysts may disappear only to possibly recur again over time.These cysts are common in all men, particularly after age 40. Because they are harmless, no treatment is generally needed for them. But, if an epididymal cyst grows and becomes uncomfortable, it can be surgically removed. Be sure to ask a doctor or urologist about any swelling around the scrotum or testes.
  • Hypospadias is a condition where the urethral opening on the penis is in the wrong place, emerging somewhere down the shaft instead of at the tip. In many cases hypospadias can be corrected with surgery.A study in Science in 1975 identified several conditions that occur more often in males exposed to DES, including hypospadias. Additional studies after that one similarly found a higher incidence of hypospadias in both DES Sons and DES Grandsons than in the general population.These problems only occur in about 5% to 8% of the general population, but they occur in DES Sons about 15% to 32% of the time, according to a 2013 study in Birth Defects Res C Embryo Today (doi:10.1002/bdrc.21035). Another study in 2008 found that DES Sons were 3.7 times more likely to have hypospadias than males not exposed to DES.

    A recent review paper, conducted by researchers at Dartmouth’s Geisel School of Medicine, published in the journal Current Environmental Health Reports-December 2018, of studies exploring how endocrine disrupting chemicals such as DES might contribute to male birth defects, shows how much more work needs to be done. Several studies, including ones from the US, France, and the Netherlands, have found a substantially higher risk of hypospadias in DES sons, and the French study found a higher risk in DES Grandsons as well. “Among the pharmaceutical agents, sex steroids, DES and progestin fertility treatments have all been associated with hypospadias risk, the researchers concluded. Most of the studies included small groups of participants, making it difficult to understand risks at the population level. Regardless, it is clear that the most sensitive time for exposure for this birth defect is during eight-16 weeks of pregnancy, and there is enough research to establish a strong link to DES. Read a more detailed account of this study in the Spring Voice 2019 #160.

  • Inflammation/Infection
    Researchers now believe that some DES Sons were born with a small structural abnormality, such as a minor obstruction that could explain what appears to be their greater risk for testicular inflammation and infection.
  • Microphallus
    Prenatal DES exposure is associated with an increased risk for a smaller than average penis. Some, but certainly not all DES Sons, were born with microphallus. It has no impact on fertility, although it can have psycho-social significance.
  • Testicular varicoceles
    Some studies have indicated that testicular varicoceles occur more often in DES Sons than in unexposed men. A varicocele is an irregularly swollen or varicose vein on the testicle. This enlarged vein produces a higher temperature than is normal for testicles and, as a result, over a period of years, can lower the number of normal sperm.
  • Infertility
    There is growing scientific evidence that DES Sons are slightly more likely than unexposed men to experience infertility. That means DES Sons were more likely than unexposed men to report spending at least a year unsuccessfully trying to father a pregnancy. But researchers with the on-going National Cancer Institute DES Follow-up Study say most DES Sons are able to father children. However, the scientists say they saw enough in their analysis to speculate that DES Sons may experience increasing infertility problems as they age. The researchers are continuing their work in this area.
  • Testicular Cancer
    No DES-specific testicular cancer has been found; however, research shows that congenital abnormalities such as undescended testicles predispose men to testicular cancer. Therefore, DES Sons, with a higher rate for such urogenital anomalies, might be considered as a high-risk group. All men should practice testicular self-exam regularly. A study from June 2019, Journal of the National Cancer Institute Cancer Spectrum entitled: Systematic Review and Meta-analysis of Testicular Germ Cell Tumors Following In Utero Exposure to Diethylstilbestrol concludes that it is likely that prenatal exposure to DES, and other chemicals like DES, could contribute to the development of testicular cancer cells in males. The odds of testicular cancer were three times greater in DES Sons than in unexposed men, meaning that three out of 250 DES Sons could be afflicted. Members can login to read the article that covers this study in the Winter Voice 2020 in the Archived Voices section.
  • Prostate Cancer (Possible)
    Since many DES Sons are just reaching the age when prostate cancer may occur, there have not yet been reports of an increased incidence of prostate cancer among DES Sons. That said, animal studies have pointed to the possibility of an increased risk for DES-exposed men, leading some researchers to speculate that DES Sons might be at higher risk and should pay attention to the possibility.
  • Cardiovascular Disease, Diabetes and Osteoporosis
    DES studies continue with additional medical issues now possibly linked to exposure. These conditions have been found to occur in higher rates for DES Sons and DES Daughters compared with those who were not exposed.

    • diabetes
    • high cholesterol
    • hypertension
    • cardiovascular disease (stroke, coronary artery disease and myocardial infarction)
    • osteoporosis
    • Fractures

    Specifics on the findings developed from NCI DES Follow-up Study research are in a DES Action VOICE newsletter article.

    Scientists had been seeing mounting evidence that endocrine disruptors, of which DES is one, are implicated in increased risks for cardiovascular disease. Therefore, this study’s results were not totally unexpected.

    DES exposure has been linked in the latest study, on Cardiovascular Disease, and it may apply to men as well, but this 2018 study only included women prenatally exposed to DES, while the 2013 study included both DES sons and DES Daughters. To learn more about these studies, see the Cardiovascular disease study link:

    No special screenings or treatments have been identified, but DES Sons should stay aware of potential increased risks and discuss appropriate screenings with their doctors.

DES has been linked to a number of other conditions that may affect men as well but have only been studied in women. To learn more about these studies, see the studies under the DES Daughters tab

Sex, Sexuality and Gender

Endocrine disrupting compounds are being examined in gender identity studies, but so far DES research has not found a conclusive DES link. One confounding thought now under investigation regards the layering of endocrine disruptive exposures, both prenatally and perinatally. Researchers want to understand if there is an association and then whether DES exposure might itself be a cause or, perhaps combined with other exposures, be a trigger for variations.

Questions have been routinely raised in the DES community regarding the possibility that prenatal DES exposure may be linked to increased rates for homosexuality, transgender and transsexual conditions. Animal studies point in that direction yet, so far, no evidenced-based research in human populations has been able to confirm it. This article from 2003 on DES and sexuality ran in the DES Action VOICE newsletter describing what researchers were seeing in human studies then. However, a new research study from the National Institute of Health DES cohort study titled: Gender Identity and Sexual Orientation Identity in Women and Men Prenatally Exposed to Diethylstilbestrol appeared in Archives of Sexual Behavior in January 2020. Until now, there have been no credible studies attempting to quantify the DES LGBTQ+ community in comparison to those unexposed. This study sheds a bit more information on this topic. This new study was covered in our Spring Voice 2020. Members may login and find it in the Archived Voices section. For more discussion on this study, and DES exposure and Human Sexuality, Sex and Gender studies click here.

To understand the struggles faced by transgender individuals read a letter that was sent to DES Action. But note that some statements may not hold up to scientific scrutiny.

In a VOICE newsletter commentary the late DES Action USA Co-founder Pat Cody examined why it is difficult for researchers to study behavioral and sexual questions and develop definitive answers. For more discussion and studies on DES Exposure and Human Sexuality, Sex and Gender go to our LGBTQ+ page



DES as an Endocrine Disruptor

Of note is that DES is an endocrine disrupting chemical. The DES community is described as the “poster population” for what can happen when individuals are exposed to these chemicals before birth. The DES experience triggered research into endocrine disruptors and how hormonally active substances interfere with prenatal development and can cause adverse health outcomes later in life.

Another such chemical is bisphenol A (BPA), a synthetic estrogen that has a chemical structure very similar to that of DES. Health impacts linked to BPA are remarkably familiar to those known to be associated with DES exposure but occur at much lower doses.

This is an important distinction between the two that must be taken into account: Pay attention to the exposure dose.

Also, because many of these exposures are common in our environment, rather than exposure through a drug like DES, identifying and eliminating the exposure potential can be challenging. Here’a a link with ways to reduce environmental exposures in our daily lives.



A September 2019 study in the journal Epidemiology surveyed nearly 5,000 DES-exposed and over 2,700 unexposed participants in the NCI’s DES Combined Cohort Follow-up Study (DOI: 10.1097/EDE.0000000000001048). Among women, 26% of DES Daughters and 23% of unexposed women reported depression, and 17% of both DES Sons and unexposed men reported depression. The researchers found no statistically significant increased risk of depression in DES Children, even when limited to those taking antidepressants. They controlled for various factors, including physical health problems, but not family history of depression. However, the authors did find a weak association between DES and depression for only DES Daughters with a low exposure dose or exposure before 8 weeks gestation: They were 1.2 times more likely to have depression than unexposed women. The depression diagnoses weren’t related to whether the DES Daughters had abnormal findings in the vaginal lining or any other DES-related problems. The researchers concluded “We found a potentially slightly increased risk of depression in women who were exposed very early in gestation. Also noted was a weak link in women and men exposed to a low cumulative prenatal dose of DES, but among men this was apparent only after accounting for other factors.” Together, this research shows that a link between DES exposure and depression cannot be completely ruled out, but there isn’t enough evidence to suggest depression is any more likely in DES Daughters and Sons than in the general population.

Emotional Impacts

DES creates emotional trauma for all who come in contact with it: DES Mothers (and Fathers), DES Daughters, DES Sons, and DES Grandchildren.

Men traditionally are reticent to talk about the kind of highly personal issues that DES creates. It is often their mothers and wives who begin searching for information regarding exposure. DES Sons can experience the same anxieties, anger and relationship turbulence as DES Daughters. Experience shows that keeping lines of communication open can be helpful. Doing so with accurate and timely information regarding exposure is very useful. Taking action can reduce feelings of helplessness. Getting up on our soapbox now – Joining DES Action can be one step toward healing. Members get new information throughout the year and feel good about doing something positive by supporting an organization actively pushing for more DES research.


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