Exposure to sex hormones (like testosterone), or environmental pollutants that mimic sex hormones, has been found to significantly lower the sperm count and future fertility of a developing male fetus, according to a new study in Endocrinology. "The majority of disorders affecting sperm count in humans are originated during fetal life," noted the lead author of the study, Professor Sergio Recabarren. "A developing fetus is very vulnerable to its environment, and when that environment is exposed to excess sexual steroids [hormones], it may have a significant deleterious effect on a male offspring's fertility."
Dr. Recabarren, from the University of Concepcion in Chile, explained that prenatal exposure can occur in two ways. The exposure may be due to increased hormonal levels in the maternal environment due to a condition such as polycystic ovary syndrome, or, the mother may be exposed to industrial pollutants which can act as steroid "mimics," causing the body to inhibit or accelerate normal hormonal production.
In this new study, the researchers treated pregnant sheep with 30 mg testosterone propionate twice weekly from days 30 to 90 of pregnancy and with 40 mg testosterone propionate from days 90 to 120 of pregnancy. They found a significant reduction in body weight, scrotal circumference, and sperm count in male sheep born to these mothers compared with sheep from the control group.
"While this research involved sheep, it can certainly be argued that in humans, exposure to an excess of sexual steroids during fetal development could constitute a potential risk factor that may [result in] a low sperm count," said Dr. Recabarren.
Related:
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Source: The Endocrine Society
