Men in their mid 30's: Too Late to be a Father?

Jul 07, 2008
It seems that men do not have much time left to have a baby as their biological clock starts ticking in their mid 30s. Scientists found that chances of successful pregnancy drops significantly if a man is over 35 years old and are much lower if he is over 40 years old.

The findings of the French study of 12,200 couples undergoing fertility treatment was presented at the European Society of Human Reproduction and Embryology conference. It says that paternal influence becomes even more important than earlier thought.
The researchers at the Eylau Centre for Assisted Reproduction in France studied couples having artificial insemination as a treatment for infertility between January 2002 and December 2006.

During this procedure called intrauterine inseminations (IUI) the man's sperm is placed into female's uterus during ovulation. IUI treatment is considered to be less invasive in comparison to IVF( in vitro fertilization) method. It is also often used for women without a partner, having no fertility problems to produce children using a sperm donor.

The team analyzed the quantity and motility of the sperm, as well as other characteristics such as the size and the shape of the sperm. The researchers also recorded the number of pregnancies, miscarriages and birth resulting from the fertility treatment. They examined the detailed data on the pregnancies to isolate paternal and maternal factors.

The study showed that the rate of miscarriage increased if the man was in his late 30's. The chances of successful pregnancy decreased even more if a father was over 40 year old.

As expected, women over 35 year old had more difficulties in getting pregnant and higher rates of miscarriage than younger ones, but the paternal factor was strong too. If a father was over 40 years old the risk of miscarriage increased up to 35 percent, while for a man younger than 30 the risk is estimated between 10 to 15 percent, Yves Menezo, one of the researchers said.

Previous studies showed that sperm count and quality declines as a man ages, but until now there was little evidence that the age of a man plays such an important role on fertility.

The researchers think that the reproductive decline is caused by DNA damage in sperm. The samples of the sperm taken from men over 40 showed more defects that might resulted in miscarriage, researchers said.

"Until now, gynecologists only focused on maternal age, and the message was to get pregnant before the age of 35 or 38 because afterwards it would be difficult," Dr Stephanie Belloc, who presented the work at the conference in Barcelona, said. "But now the gynecologists must also focus on paternal age and give this information to the couple."

She said that couples seeking fertility treatment must be offered IVF method to increase their chances of a successful pregnancy. During this process, an egg is fertilized outside the woman's womb, in a lab dish, where the outer membrane of the egg may prevent sperm with DNA decay from fertilization. Couples may also use ICSI method where an egg is fertilized by the best sperm selected for this purpose.