Biological Clocks Tick for Men, Too

"As men get older, there is an increase in the risk of having that fragmented DNA," Schlegel explained. Dah!


But the study also found that if the father was in his late 30s, the chances of a successful pregnancy went down. Ten percent of treatments led to pregnancy in fathers over 40.


The father's age also affected rates of miscarriage. If a father was over 34, the miscarriage rate was 16.7 percent. Between the ages of 35 and 39, it went up to 19.5 percent. And if the father was older than 44, it jumped to 32.4 percent -- which means nearly one-third of the pregnancies ended in miscarriages.

Researchers said the problems were likely the result of DNA damage and fragmentation in sperm, which can lead to pregnancy failure and miscarriage.

Dr. Peter Schlegel, chairman of urology at the Weill Cornell Medical Center in New York, works at the Male Center for Reproductive Medicine. He told ABC News it is possible that there is a link between DNA damage and age.

"As men get older, there is an increase in the risk of having that fragmented DNA," Schlegel explained.