Men Over 40 Less Fertile Than Younger Ones: Study

Like a woman, a man’s age is also crucial for a successful pregnancy, a French research says. Couples intending to conceive face higher difficulty and fertility risks when the man ages beyond 40 years, the new research finds.

"Our data give evidence for the first time, for a strong paternal effect on IUI (intrauterine insemination) outcome either on pregnancy rates but also on miscarriage rates," Dr Stephanie Belloc, researcher at France’s Eylau Centre for Assisted Reproduction, said while presenting the work to the European Society of Human Reproduction and Embryology (ESHRE) conference in Barcelona.

For the study, the researchers screened over 21,000 cases of intrauterine inseminations (IUI) in over 12,000 couples between January 2002 and December 2006.

An intrauterine insemination, a fertility treatment that is administered to couples where the woman has no fertility problems, is a clinical procedure in which the sperms are washed or spun in a centrifuge to separate them from the seminal fluid and then inserted directly into the female's uterusdefine for the purpose of impregnating her.

The team then inspected the sperm quality, their ability to move and swim and their size and shape. Pregnancy, miscarriage and delivery rates were then recorded.

As expected, the higher maternal age was closely linked to higher failed pregnancy and miscarriage risk, but surprisingly, paternal age, below 40 years, was also found to be an important key to successful pregnancy.

As the age of the male counterpart increased, the chances of a successful pregnancy lowered, researchers marked. Pregnancy rates dipped form 12.3 percent with fathers 30 years of age or younger, to 9.3 percent in fathers older than 45 years of age.

Also alarming were the miscarriage rates that soared from 13.7 percent in fathers aging 30 or younger to 32.4 percent in fathers older than 45 years of age.

Meanwhile, though the exact cause of depleting sperm quality with age is not know, researchers believe the problem is likely to be caused by DNA damage in the sperm.

However, fertility treatment experts "must also focus on paternal age and give this information to the couple" and not only on the maternal age, as they have done it before, researchers mark.