Women tend to live longer if they give birth naturally later in life, US research has shown.
Beneficial genetic variants that allow women to remain fertile may be the explanation, scientists believe.
“This does not mean women should wait to have children at older ages”
The study found that women who had their last child after the age of 33 were twice as likely to celebrate their 95th birthday than those who gave birth for the last time by 29.
Lead researcher Dr Thomas Perls, from Boston University Medical Center, said: “Of course this does not mean women should wait to have children at older ages in order to improve their own chances of living longer.
“The age at last childbirth can be a rate of ageing indicator. The natural ability to have a child at an older age likely indicates that a woman’s reproductive system is ageing slowly, and therefore so is the rest of her body.”
Researchers analysed data from the Long Life Family Study (LLFS), a social and genetic investigation of 551 families containing many exceptionally long-living members.
The scientists determined the ages at which 462 women had their last child, and how long those women lived to be.
The findings indicate that women may be the driving force behind the evolution of genetic variants that slow ageing.
“If a woman has those variants, she is able to reproduce and bear children for a longer period of time, increasing her chances of passing down those genes to the next generation,” said Professor Perls.
“This possibility may be a clue as to why 85% of women live to 100 or more years while only 15% of men do.”
The study is due to be published in Menopause: The Journal of the North American Menopause Society in January 2015.