Children of younger mothers may live longer as the women are less likely to have acquired latent infections that could harm the health of the foetus, say scientists.
Researchers Natalia Gavrilova and Leonid Gavrilov of the University of Chicago studied 991 centenarians born in the US between 1875 and 1899 for the study.
The younger mothers are less likely to have acquired various infectious diseases during their life that could damage the health of the foetus, the researchers were quoted in the online edition of New Scientist as saying.
The researchers used US Census and Social Security Administration records to reconstruct the family histories of 198 of them, searching for anything they had in common.
It turned out that first-born children were 1.7 times as likely as their siblings to live to be 100. An even stronger predictor of longevity was how young their mother was when they were born.
Younger mothers may also have better-quality eggs, according to the research.