Miscarriage linked to older fathers
Monday, 07 Jul 2008 09:16
Age of the father can affect fertility, study finds
Science In Focus
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Women who have children with men aged over 35 are more likely to have a miscarriage, scientists warned today.
The researchers from the Eylau Centre for Assisted Reproduction, Paris, also claimed that pregnancy rates decrease when the male partner is approaching middle age.
Previous studies have linked the age of the mother to problems in pregnancy but the role of the father's age is still controversial.
For the latest study Dr Stephanie Belloc and colleagues analysed 21,239 intrauterine inseminations (IUIs) - a fertility procedure where the sperm is 'washed' and then inserted directly into the uterus.
The sperm of each partner was examined at the time of the IUI for a number of characteristics, including sperm count, motility (movement) and morphology (structure).
Pregnancy, miscarriage and delivery rates were also carefully recorded.
The results were presented today at the annual conference of the European Society of Human Reproduction and Embryology.
Maternal age was closely associated with a decreased pregnancy rate of 8.9 per cent in women over 35 years, compared to 14.5 per cent in younger women. Miscarriage rates were also typically affected by maternal age.
"But we also found that that the age of the father was important in pregnancy rates – men over 35 had a negative effect," said Dr Belloc. "And, perhaps more surprisingly, miscarriage rates increased where the father was over 35."
The researchers say that their findings show how DNA damage in the sperm of older men can affect fertility.
They argue that the study has important implications for couples wanting to start a family and they plan to test the results in larger studies.
"How DNA damage in older men translates into clinical practice has not been shown up to now," said Dr Belloc.
"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 programmes."