Damage to DNA in sperm is significantly higher in older men than in those who are younger, according to research presented today (Tuesday 21 June 2005) at the 21st annual conference of the European Society of Human Reproduction and Embryology.
Dr. Sergey Moskovtsev, of the Mount Sinai Hospital, Toronto, Canada, told the conference that an increase in the average maternal and paternal ages at the time of attempted first pregnancy made this particularly significant. "Older men tend to reproduce with older women", he said, "and the combination of increased female factor infertility, increased sperm DNA damage, low levels of DNA repair, and increased abnormalities in conventional semen parameters present in this population will have a pronounced impact on their reproductive potential."
Dr. Moskovtsev and his team examined the relationship of DNA integrity, a novel semen parameter related to fertility potential, to age in 2134 men presenting for evaluation of their fertility. They identified damaged and normal sperm by means of a fluorescent dye that attaches to DNA, staining red when attached to damaged DNA and green to normal. Using 20 000 sperm per sample, they calculated DNA damage in each specimen via the ratio of red to green plus red. They found that DNA damage was significantly higher in men over 45 years old than in all younger age groups, and that the damage was doubled in those men 45 years and older compared with those less than 30 years old.