While it is common knowledge that women have to worry about their reproductive clock after going past a certain age, a new study suggests that even men have to deal with the phenomenon as the quality of their sperm starts to deteriorate once they are past the age of 35.
The research also found that the X chromosome carrier sperms also seem to be on a rise, which means that the older dads have more chances of fathering a girl.
Bronte Stone at Reproductive Technology Laboratories in Los Angeles and his team tested sperm quality in samples from 5081 men in the age group of 16 and 72.
The resulting study found that there was deterioration in quality of sperm and quantity after the age 35, New Scientist reported.
The study also found that the ratio of Y to X-bearing sperm went down once men hit 55, though there is no clarity in why this phenomena happens.