Men whose mothers had gone through severe stress in early pregnancy might experience fertility problems, said a new study published in the medical journal Human Reproduction.

Researchers, who examined 2,804 women during various stages of their pregnancies and revisited their sons years later when they reached the age of 20, found that 63 percent of men whose mothers experienced stress had lower testosterone levels and sperm counts.

“This suggests that maternal exposure to stressful life events during early pregnancy, a vulnerable period for the development of male reproductive organs, may have important life-long adverse effects on men’s fertility,” says Roger Hart, senior author of the study and Professor of Reproductive Medicine at the University of Western Australia.

“This contrasts with the absence of any significant effect of exposure to maternal stressful life events in late gestation,” he added.

“Our findings suggest that improved support for women, both before and during pregnancy, but particularly during the first trimester, may improve the reproductive health of their male offspring," Hart stressed.

“Men should also be made aware that their general health is also related to testicular health, so they should try to be as healthy as possible to ensure that not only do they have the best chance of maintaining fertility, but also of remaining healthy in later life.”