An Old Mom Keeps You Young: Mother’s Age at Last Birth and Offspring Longevity in Nineteenth-Century Utah

Abstract

This study analyzes the intergenerational effects of late childbearing on offspring's adult longevity in a population in Utah (United States) that does not display evidence of parity-specific birth control-a so-called natural fertility population. Studies have found that for women who experience late menopause and prolonged reproduction, aging is postponed and longevity is increased. This is believed to indicate female "robustness" and the impact of biological or genetic factors. If indeed there is a genetic component involved, one would expect to also find evidence for the intergenerational transmission of longevity benefits. Our study investigates the relationship between prolonged natural fertility of mothers and their offspring's survival rates in adulthood. Gompertz regression models (N = 7,716) revealed that the offspring of mothers who were naturally fertile until a relatively advanced age lived significantly longer. This observed positive effect of late reproduction was not independent of but conditional upon survival of the mother to the end of her fecundity (defined as age 50). Offspring's relative risks at death beyond age 50 were 6-12 percent lower than those of their counterparts born to mothers who had an average age at last birth. Our results, which account for various early, adult, and later-life conditions, as well as shared frailty, suggest that there is a positive relationship between mother's age at last birth and offspring longevity, and strengthen the notion that age at menopause is a good predictor of this relationship.

Intergenerational transmission of longevity is not affected by other familial factors: Evidence from 16,905 Dutch families from Zeeland, 1812-1962

“…Before age 5, offspring of long-lived fathers had a smaller survival advantage of 7%. The survival advantage enjoyed by offspring of long-lived mothers remained roughly 20%, but was modest in comparison to known additive effects of high infant mortality in the sibship (Broström, Edvinsson & Engberg, 2018;Hin, Ogórek & Hedefalk, 2016;Janssens, Messelink & Need, 2010;Sommerseth, 2018;, descending from a small family (Doblhammer & Oeppen, 2003), parental birth spacing (Dewey & Cohen, 2007;Kozuki et al, 2013), or having a farming father (Breschi et al, 2011;Edvinsson et al, 2005;Janssens & Pelzer, 2012;Schumacher & Oris, 2011;Van Poppel, Jonker & Mandemakers, 2005). However, the survival advantage enjoyed by offspring of long-lived parents is indicative of one of the mechanisms behind child mortality.…”

“…Associations between family fertility histories and offspring survival have been less thoroughly studied. Hin, Ogórek, and Hedefalk (2016) reported that having a late-reproducing mother or fewer siblings associated with increased survival after age 50. However, we found no evidence that having a late-reproducing mother, lower birth order, longer birth intervals, or younger parents associated with offspring survival associated with offspring survival between ages 5-100.…”

“…Farmers' and upper class children had a survival advantage over children from other parents (Breschi et al, 2011;Edvinsson et al, 2005;Janssens & Pelzer, 2012;Schumacher & Oris, 2011;Van Poppel, Jonker & Mandemakers, 2005). There is some evidence that the differences in survival between offspring of farmers, the elite, the middle class, and laborers remains present over the rest of the life course (Breschi et al, 2011;Hin, Ogórek & Hedefalk, 2016;Schenk & van Poppel, 2011;Van Den Berg, Lindeboom & Portrait, 2006). However, studies focused on the association between individual socioeconomic status and later-life survival in commercial-agricultural societies generally did not find any socioeconomic effects on differences in mortality rates (Bengtsson & van Poppel, 2011;Edvinsson & Broström, 2012).…”

“…the family farm, smithy, bakery, or store. Earlier born siblings are known to have lower mortality rates (Barclay & Kolk, 2015;Engelen & Wolf, 2011;Hin, Ogórek & Hedefalk, 2016;Smith et al, 2014;Sommerseth, 2018;, but it is not known whether this is caused by maternal depletion, resource competition, or selective parental investment.…”

“…Due to the high mutation load, both can be detrimental to the health of their children and shorten their lifespan (Gavrilov & Gavrilova, 2000;Xie et al, 2018). Possibly as a result, later born children seem to show higher mortality rates (Barclay & Kolk, 2015;Engelen & Wolf, 2011;Hin, Ogórek & Hedefalk, 2016;Smith et al, 2014;Sommerseth, 2018;.…”