Lead researcher Professor Dolores Malaspina, of the Columbia University College of Physicians and Surgeons, said her findings showed "a man has a biological clock too".

BBC: 'Older fathers' link to schizophrenia

Darren Spedale, 38, the website's founder, says he started the company in 2012 after realizing his own biological clock was ticking but he didn't have someone with whom to raise a child.

WSJ: Tech's Over-Sharing Economy

Darren Spedale, 38, the website's founder, says he started the company this year after realizing his own biological clock was ticking but he didn't have someone with whom to raise a child.

WSJ: Tech's Over-Sharing Economy