DES Sons, Endocrine Disruption, and Male Reproductive Health: Comprehensive Research Trends 1959-2025

November 2025 Comprehensive Update from the DES Information and Research Network

Scott Kerlin, Ph.D.

Overview

This guide is focused on research into male reproductive health trends, with an emphasis on DES-exposed males (“DES Sons”) published between 1959 and 2025. DES Sons are persons born male who were born to mothers who were treated with the drug diethylstilbestrol (DES) to prevent miscarriage.

DES Sons have often been referred to as “the forgotten piece of the jigsaw.”

There were as many DES Sons as DES Daughters born in the U.S. and other countries where it was prescribed during the prime period of late 1940s to early 1970s, but far less research and advocacy on behalf of DES Sons has occurred over the years. Nearly 90% of the primary research on the human health effects of DES has been limited to DES Daughters and most of the public health research, education and advocacy has centered around concerns of DES Daughters only.

Several recent studies of “DES Grandsons” (i.e. males born to prenatally-exposed females and males) have been published in recent years and are included in this review.


Primary documented health effects in DES Sons

The adverse effects of prenatal DES exposure reported in research with persons born male include:

* Cryptorchidism–Extremely small testes and/or undescended testes
* Epididymal cysts–Benign cysts (fluid-filled sacs) that feel like small lumps
* Hypospadias–Opening of the penis is in the wrong place, often corrected with surgery
* Microphallus–Increased risk for a smaller than average penis
* Testicular Variocoeles–Irregularly swollen or varicose vein on the testicle
* Urethral Stenosis–Scarring that narrows and constricts the urethra
* Other disorders of sexual differentiation (DSD) and intersex condition at birth
* Testicular Cancer Risk–A major study of DES Sons in 2019 documented elevated risk of testicular germ cell cancer at 3 times the rate of non-exposed males
* Prostate Cancer Risk–Confirmatory research is divided
* Cardiovascular Disease
* Infertility–Potential for increased risk of infertility in DES Sons as they age
* Hypogonadism (Testosterone deficiency, in primary or secondary form)
* Disorders of sexual differentiation (DSD) and intersex condition at birth
* Psychological and psychiatric effects
* Sexuality and gender identity effects including transgender** (** see separate page for further references in this area)

Some recent published studies have also documented the continued therapeutic uses of DES for the treatment of patients with castration-resistant prostate cancer.

** NOTE: The references included in this page include studies on the core areas of endocrine disruptor impact that have been documented in males. As such, the literature on male reproductive health and medicine have been continually reviewed and updated in order to provide a broad context of continuing research investigation, all in the interest of strengthening avenues of awareness about heretofore neglected issues. Scientific studies of environmental endocrine disruptors which include DES that include some type of focus on males (in part or in whole) are included.

Note Regarding Research on Endocrine Disruptors and Testicular Dysgenesis Syndrome (TDS): DES was first classified as an Endocrine Disrupting Chemical (EDC) two decades ago, and since that time a wide variety of research on EDCs has included focus on DES. Since 2001 (Skakkebaek et al., 2001) TDS has been associated with endocrine disruption and is defined as characterized by poor semen quality, undescended testis, cryptorchidism, hypospadia, testicular cancer, and disruption of normal processes of male sexual differentiation.


My Ongoing Research with DES Sons, Sexuality and Gender Diversity

My own DES research for the past 30 years has focused on assessing the range of health, medical, and psychosexual and psychiatric issues raised by members of the DES Sons International Network (N=1000), and is discussed in more detail in this separate page: Academic Research Into Prenatal Hormonal Influences on Gender and Sexual Development.

I have contributed my research to 2 recently published articles from France:

* “Early Female Transgender Identity After Prenatal Exposure to Diethylstilbestrol (DES): Cause of Coincidence? Results from a French National Cohort” in the Journal of Xenobiotics in January 2024.

** An extension of this study was published in 2025: Gender identity disorders: a legacy of fetal exposition to Diethylstilbestrol, an Endocrine Disruptor Chemical, in the Medical Research Archives from the European Society of Medicine.

As a broader extension to my DES research, I have devoted many years to deeply researching the subjects of gender identity, gender dysphoria, transgender and non-binary identity, and human sexuality. If you share my interests, I invite you to visit my comprehensive directory of sexuality and gender identity resources.

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Journal Article Published References 1959-2025

2022-2025