Big Families May Be Bad For Mom And Dad

University of Utah researchers say having a large number of offspring could be detrimental to the health of parents.

The study, based on data collected from 21,000 couples who lived in Utah between 1860 and 1985, said parents with higher numbers of children are more likely to have ill health and die younger, the BBC reported Tuesday. The study said this is especially acute in women.

The researchers said their findings may explain the occurrence of menopause, which ends the reproductive years of women.

"Menopause appears to allow mothers to live longer and rear more offspring to adulthood and this unusual life history probably evolved in our species because, as we found, offspring so extremely depend on their mother's survival," the researchers said.

The authors said the findings also explain why modern women tend to have fewer children than in the past.

"If women have generally incurred greater fitness costs of reproduction, this could explain why they generally prefer fewer offspring than their husbands and reduce their fertility when they obtain more reproductive autonomy."