THE very few women who have children after the age of 45 may be able to do so because anti-ageing mechanisms are more active in their bodies.
鈥淚t might be possible to predict the chances of success of fertility treatment in older women based on their gene expression profile鈥�
Neri Laufer鈥檚 team at Hadassah University Hospital in Jerusalem recruited eight women who had given birth after the age of 45. 鈥淭hey are a unique group of patients,鈥� he says. His team compared levels of gene expression in the women鈥檚 blood with levels in six mothers of the same age who had chosen not to have any more children after the age of 30. They found differences in 716 genes.
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Intriguingly, many of the genes that were more active in the fertile over-45s are involved in repairing DNA damage and preventing cell death. That would help counteract the effects of ageing, especially ageing of the ovaries, Laufer told a human reproduction conference in Copenhagen, Denmark, this week. His team also plans to look at whether the women live longer.
While it is possible that having lots of children causes these differences 鈥� the fertile over-45 group had an average of nine children each compared with just two for the controls 鈥� Laufer thinks it more likely that the women were born with this propensity. Their miscarriage rate was lower than normal, he points out, and did not change as they had more children.
While the study was small and all the women involved were Ashkenazi Jews, Laufer says preliminary results from another group suggest the results apply to all women. If so, it might be possible to predict the chances of success for older women seeking fertility treatment, based on their gene expression profile.
The findings should also lead to a better understanding of why fertility declines sharply in the years leading up to the menopause, and might eventually lead to treatments that extend fertility, Laufer speculates. But if DNA damage in the ovaries is to blame, there will not be an easy way to reverse it.
