Late Paternity
It’s not only older moms who bring risk to pregnancy

Pam Harrison

Recent figures from Western countries including Canada show that more older men are fathering children. More than one in 10 babies born in the U.K. in 2004, for example, were born to dads 40 years of age or older. While there are many examples of senior men siring children — Pierre Trudeau had a daughter in his 70s — there are several downsides to older dads. Here are some of the more important ones.

Miscarriage

Women impregnated by older men are more likely to miscarry. In 2006, researchers at Columbia University in New York City reported that the risk of losing her baby was 60% higher for a woman whose partner was age 40 or older, compared with a woman whose partner was between the ages of 25 and 29. The risk of miscarriage appears to increase with paternal age, regardless of the mother’s age.

A U.K. team also reported that the older a man is, the longer it takes his partner to conceive. “One of the main changes with older men is that their sperm numbers go down, so it’s a bit more difficult to achieve a pregnancy,” confirms Dr. Jerald Bain, an endocrinologist at Toronto’s Mount Sinai Hospital and a professor emeritus of medicine at the University of Toronto.

Higher rates of child disorders

Children born to older dads are at greater-than-usual risk for certain disorders. A U.S.-Israeli study reported that children born to the oldest fathers in a sample group were three times more likely to develop schizophrenia than children born to younger men. Age was felt to be responsible for about 25% of this increased risk. Though the risk of schizophrenia was still low in children born to older men (3%), the association between greater paternal age and increased schizophrenia risk in their  children has been documented in other studies.

“There is not only a decline in semen volume with age but also in sperm quality,” notes Dr. Keith Jarvi, a professor of surgery at the University of Toronto. “So there may be some damage to the DNA of the sperm as men age.” In one investigation in the U.K., men between the ages of 36 and 57 had three times the amount of DNA damage in their sperm than men under 35.

Damaged DNA is more likely to be passed on to children as a male ages, potentially increasing the risk not only of schizophrenia but also of autism, cleft lip and cleft palate, Down’s syndrome and certain cancers. A study of European royal families also revealed that daughters (though not sons) born to men in their 50s were more likely to die earlier in life than daughters born to men in their 30s. 
 
Late vasectomy reversal

If a reversal is done within three years or so of the vasectomy, says Jarvi, there’s a 95% chance that sperm will make their way back into the ejaculate. Pregnancy rates will be high (about 75%). In contrast, if a man decides to become a father later in life and undergoes reversal 20 years after a vasectomy, the amount of restored sperm in ejaculate is still high, but pregnancy rates drop to about 25%.

“You can do a phenomenal repair and get a great sperm count, but if the woman is also biologically older — say, in her early 40s — pregnancy rates are very low,” Jarvi warns.