Stress may impact male fertility

October 23, 2009 by Shawn Douglas
Filed under: News, Pregnancy

Stress hormones and a common chemical in plastics, when combined, may cause fertility problems for male babies while in the womb.

Researchers at Edinburgh University have found that high levels of stress hormones mixed with a common chemical found in plastics severely inhibited male fetal development in rats.

The study gave some pregnant rats the chemical compound dibutyl phthalate, a chemical found in many household goods including credit cards and vinyl shower curtains. Afterwards, some of the rats were injected with a stress hormone while others were not.

Of those rats that were only dosed with phthalate, there were some adverse effects to fetal development noted. However, those rats that received both phthalate and stress hormone showed significantly high levels of reproductive birth defects in the offspring.

The study may be applicable to humans and may help to shed light on why there is an increasing rate of male babies born with reproductive defects. A condition called cryptorchidism—when the testicles do not drop—affects nearly seven percent of British boys, and often leads to infertility.

Edinburgh University’s Dr. Mandy Drake said, “What the study shows is that it is not simply a case of one factor in isolation contributing to abnormalities in male development but a combination of both lifestyle and environmental factors, which together have a greater impact.”

“In most studies reproductive disorders are only seen after abnormally high levels of exposure to chemicals, which most humans are not exposed to.”

“Our study suggests that additional exposure to stress, which is a part of everyday life, may increase the risk of these disorders and could mean that lower levels of chemicals are required to cause adverse affects.”

The study, performed in collaboration with the Medical Research Council’s human reproductive sciences unit, was published in the journal Endocrinology.