Determining the impact of paternal age on pregnancy rates and outcomes among couples undergoing intrauterine insemination. 
Couples undergoing infertility treatment experience lower pregnancy and higher miscarriage rates if the father is over 40 years of age than if he is younger, French scientists have discovered.

Stéphanie Belloc, from the Eylau Center for Assisted Reproduction in Paris, France, and colleagues studied 21,239 intrauterine inseminations (IUIs) carried out in 12,236 infertile couples treated between 2002 and 2006.

At the time of IUI, the sperm were examined for sperm count, motility, and morphology. In addition, clinical pregnancy, miscarriage, and delivery rates were recorded.

As expected, maternal age affected the pregnancy rate, which was 8.9 percent in women aged over 35 years compared with 14.5 percent in younger women. Miscarriage rates also increased with maternal age.

“But we also found that the age of the father was important in pregnancy rates-men over 40 had a negative effect,” Belloc commented. “And, perhaps more surprisingly, miscarriage rates increased where the father was over 40.”

She added: “How DNA damage in older men translates into clinical practice has not been shown up to now. Our research proves for the first time that there is a strong paternal age-related effect on IUI outcomes, and this information should be considered by both doctors and patients in assisted reproduction programs.”

ORGYN.com