When you hear the phrase "biological clock", you think of women, right? Well, new research indicates that men may face a similar timeline.
French researchers studied the pregnancy rates of women inseminated with sperm from men of all ages. After studying more than 21,000 inseminations, they found that sperm from men over age 35 was more likely to have defects that could cause miscarriage. The rate for miscarriage was about 35 percent among men over age 40, compared to just 10 percent among men younger than 30.
The study was presented at a conference of the European Society of Human Reproduction.