Age and fertility also an issue for men

Age and fertility also an issue for men
Kate Benson
July 7, 2008
IT HAS long been known that a woman's chance of reproducing declines after she turns 35, but now scientists have found that it is the same for men who have some forms of fertility treatment in their 30s.

A study by the Eylau Centre for Assisted Reproduction in Paris followed more than 21,000 men who had intrauterine inseminations at fertility clinics and found that the process, where semen is washed to extract the sperm, resulted in fewer pregnancies and more miscarriages. All the men in the study were older than 35.

"We already believed that couples where the man was older took longer to conceive," the study's author, Dr Stephanie Belloc said.

"But how DNA damage in older men translates into clinical practice has not been shown up to now. Our research shows for the first time that there is a strong paternal age-related effect on (intrauterine insemination) outcomes and this information should be considered by both doctors and patients in assisted reproduction."

She said sperm with DNA damage, common in older men, was still able to enter the egg during intrauterine insemination, which could result in failure to conceive or miscarriage.

But in the case of in vitro fertilisation, the outer membrane of the egg stopped sperm with DNA damage penetrating.

Dr Belloc followed 21,239 patients, and examined the sperm of each partner for count, motility and morphology. Pregnancy rates, miscarriage and delivery rates were also recorded.

"Some recent studies have established a relationship between the results of (intrauterine insemination) and DNA damage, which also correlated to a man's age, suggesting it might be an important factor, but until now there was no clinical proof. We have now found that the age of the father was important in pregnancy — men over 35 had a negative effect."