Offspring sex and parental health and mortality

Abstract

Increased mortality has been observed in mothers and fathers with male offspring but little is known regarding specific diseases. In a register linkage we linked women born 1925–1954 having survived to age 50 (n = 661,031) to offspring and fathers (n = 691,124). Three approaches were used: 1) number of total boy and girl offspring, 2) sex of the first and second offspring and 3) proportion of boys to total number of offspring. A sub-cohort (n = 50,736 mothers, n = 44,794 fathers) from survey data was analysed for risk factors. Mothers had increased risk of total and cardiovascular mortality that was consistent across approaches: cardiovascular mortality of 1.07 (95% CI: 1.03–1.11) per boy (approach 2), 1.04 (1.01–1.07) if the first offspring was a boy, and 1.06 (1.01–1.10) if the first two offspring were boys (approach 3). We found that sex of offspring was not associated with total or cardiovascular mortality in fathers. For other diseases or risk factors no robust associations were seen in mothers or fathers. Increased cardiovascular risk in mothers having male offspring suggests a maternal disease specific mechanism. The lack of consistent associations on measured risk factors could suggest other biological pathways than those studied play a role in generating this additional cardiovascular risk.

Inflammaging: Blame the sons. Relationships between the number of sons and the level of inflammatory mediators among post‐reproductive women

“…For example, we have shown that a higher number of sons, but not daughters, negatively influences maternal self‐rated health in later life (Galbarczyk et al, 2018). Mothers have an increased risk of cardiovascular diseases when having boys compared to girls, and increased cardiovascular mortality (Næss et al, 2017). A higher number of sons may also be associated with a shorter lifespan of mothers (Helle & Lummaa, 2013; Helle et al, 2002; but see: Beise & Voland, 2002; Jasienska et al, 2006).…”