Researchers in France have found that men have a biological clock similar to women, it has been reported.
In a study of over 12,000 couples, a team of scientists lead by Dr Stephanie Belloc found that men over 35 had increased difficulty in conceiving and rates of miscarriage rose.
Dr Stephanie Belloc said: "Our research proves for the first time that there is a strong paternal age-related effect on IUI outcomes, and this information should be considered by both doctors and patients in assisted reproduction programmes."
With the problems likely to be caused by DNA damage to the sperm, couples who are older would benefit more from assisted pregnancy using methods such as IVF, according to Dr Belloc.
"These methods, although not in themselves a guarantee of success, may help couples where the man is older to achieve a pregnancy more quickly, and also reduce the risk of miscarriage," said Dr Belloc.
According to the research, there was an 8.9 per cent decreased pregnancy rate in women over 35 compared to 14.5 per cent in younger females.
