Delaying Fatherhood Carries Risks, Studies Show

Biological clocks tick not only in women, but also for men fathering a child later in life, experts are finding.

It's not unusual to see men in their 50s and 60s starting new families. Men in their 80s can sire offspring.

"David Letterman, Charlie Chaplin — they had children at an older age," said Dr. Peter Chan, a urologist at the McGill University Health Centre in Montreal. "So that's the kind of mentality people have to think that it is OK to postpone fertility, which is fine except that they have to understand they're doing a bit of genetic gambling if they have children too late."

Having a high sperm count is no guarantee genetic material is free of age-related mutations.

Older fathers are at higher risk of producing children with physical malformations such as hemophilia and Duchenes muscular dystrophy, as well as mental disorders.

This week, one study suggested children born to men in their 50s are nine times more likely to develop autism than children born to men in their 20s or 30s.

Another study concluded men in their 50s are three times more likely to have a child that develops schizophrenia compared with those born to men in their 20s.

The problems can occur since sperm in a 50-year-old man may have gone through double or triple the number of cell divisions as sperm from a 20-year-old, said Chan.

"It's like making photocopies," he said. "The more copies you make, the lower the resolution and the lower the quality."

Researchers are beginning to understand more about the male biological clock.

They say there is no definitive answer on how old is "too old," but most sperm banks in North America won't accept donations from men older than 40.

CBC News