Age Raises Infertility Risk in Men, Too (cont.)
Effects of Age on Male Fertility
Whereas most women realize that their biological clock ticks as they age, the same cannot be said for men. "Not only are men not aware of the impact their age has on infertility, they deny it. They walk around like they're 18 years old," Fisch tells WebMD. It's no wonder.
Until recently, popular belief held that men could father children as easily at 78 as they could at 18. But a mounting body of evidence is showing otherwise.
In one study of couples undergoing high-tech infertility treatments, researchers concluded that a man's chances of fathering a child decrease with each passing year. In the study, the odds of a successful pregnancy fell by 11% every year; their chances for obtaining a successful live birth declined even farther. The study was reported in a 2004 issue of the American Journal of Gynecology.
As sure as men age, so too do their sperm. German researchers compiling the most recent data on aging sperm reported that the volume, motility (ability to move toward its destination, an awaiting egg), and structure of sperm all decline with age. They published this update in a 2004 issue of Human Reproduction Update.
Rise of Other Reproductive Risks
For aging men, the risks extend beyond reduced fertility. "The original view that men's contribution to normal reproduction stopped at fertilization needs to be completely revamped," Schlegel tells WebMD. A broader and more accurate view would acknowledge the significant impact of aging sperm on birth outcomes.
We know that once women reach their mid-30s, their risk of having a child with a genetic abnormalities increases sharply. Now we know that the age of fathers can also contribute to that risk. In the most revealing study on this topic to date, Fisch and his colleagues evaluated more than 3,400 cases of Down syndrome. They found the father's age played a significant role when both parents were over 35 at the time of conception. The effect was most pronounced when the woman was over 40. In those cases, says Fisch, "We found the incidence of Down syndrome is related to sperm approximately 50% of the time." These findings appeared in the June 2003 issue of The Journal of Urology.
Children born to older men also run a higher risk of developing schizophrenia, a devastating mental disorder. In one study on the subject, researchers discovered that men between the ages of 45 to 49 were twice as likely to have children with schizophrenia as were men 25 and younger. That risk tripled for men over the age of 50. Investigators, reporting in a 2001 issue of the Archives of General Psychiatry, drew their results from a sample of more than 85,000 people.