Men have their own biological clock

SYDNEY, Oct. 22 (UPI) -- An Australian study suggests men have a biological clock that signals a drop in fertility after the age of 35.

Researchers at Sydney IVF said sperm and DNA samples from more than 3,000 men shows DNA fragmentation of sperm increased with age, the Australian Broadcasting Corp. reported Wednesday.

The report said there was significant DNA damage to sperm in samples from men over the age of 35.

"They cannot take fertility absolutely for granted, there is also an impact of male age on fertility," Mark Bowman of Sydney IVF said.