Do environmental estrogens contribute to the decline in male reproductive health ?

About DES Sons, European Beckman Conference, Clinical chemistry, 1995


Several observations suggest that male reproductive health has been declining since World War II in many countries. The incidence of testicular cancer, hypospadias, and cryptorchidism has been increasing and semen quality has been decreasing, and these may have a common etiology.

Treatment of several million pregnant women with the synthetic estrogen diethylstilbestrol led to an increase in these conditions among the sons of these women.

The structural abnormalities of the reproductive organs more frequently reported in males exposed to DES than in controls include meatal stenosis, hypospadias, epididymal cysts, and testicular abnormalities. McLachlan reported similar abnormalities in the male offspring of mice exposed to DES. Dieckmann et al. performed a double-blind placebo-controlled study in the 1950s. DES was given to 840 women between the 7th and 35th gestation week. Of the offspring of these mothers, 308 men were exposed to DES and 307 men were exposed to placebo; 31.5% and 7.8%, respectively, had abnormal reproductive tracts. Whitehead and Leiter reported genital abnormalities in 29 of 48 DES-exposed men. These data are convincing and cannot be explained by differences in confounding factors.

Gill et al. studied semen samples from 88 men exposed to DES and 85 men exposed to placebo who were offspring of the Dieckmann cohort. Sperm concentration was much lower among men exposed to DES. There was no difference in semen volume, whereas the total sperm count, the sperm motility grade, the total number of motile sperm, the percentage of sperm with normal morphology, and the quality score were all statistically lower in men exposed to DES. In a later study of the same men, only semen concentration differed in the two groups. Similar findings were reported in another study including 17 men exposed to DES and 12 controlsubjects.

These abnormalities probably arise during fetal development. The similarity between these effects and the adverse change in male reproductive development and function raised the question of whether the adverse changes are attributable to altered exposures to estrogenic and other endocrine-disrupting agents during fetal development. We speculate that alteration in exposure to estrogen in the past half-century may have caused the changes in male reproductive health.


  • Read the full text (free access) : Do environmental estrogens contribute to the decline in male reproductive health?, Clinical chemistry, NCBI PubMed, PMID: 7497651, 1995.

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