Are Girls Good and Boys Bad for Parental Longevity? : The Effects of Sex Composition of Offspring on Parental Mortality Past Age 50.

Using historical data from the Utah Population Database, this analysis finds significant, consistent, but small adverse mortality effects for mothers after age 50 who had mostly sons. Examination of age-dependent effects indicates that this association increases with mother's age. Additionally, mothers who had mostly daughters faced mortality risks that increased with age. Offspring sex composition did not have a significant effect on paternal mortality. Interaction analyses were conducted to examine the effect of offspring sex composition with regard to historical period, residential location, socioeconomic status, and childhood survival. No other interactions were found to be statistically significant. Having mostly boys remained detrimental to maternal mortality regardless of childhood survival.