BBC NEWS | Health | Male biological clock 'ticks too'

BBC NEWS | Health | Male biological clock 'ticks too': "Scientists say they have found more evidence that men as well as women have biological clocks and that they start to tick in their mid-30s.

A French study of over 12,200 couples having fertility treatment suggests the chance of a successful pregnancy falls when the man is aged over 35.

It adds that the chance is significantly lower if he is over 40.

Previous studies have shown that both natural and assisted conception is more difficult if the man is over 40."