Maternal early life conditions and offspring sex ratio at birth in 19th and 20th Century Scania

The importance of early life conditions for health in later life has been known for many years. Recent developments in modelling techniques have given rise to a series of in-depth studies that focused on educational attainment, labour market outcomes, adult health, the incidence of particular diseases and old-age mortality. However, not many studies look at the impact on health during early adulthood and, in particular, the literature that analyses how early life conditions affect female reproductive health is scant and often inconclusive. Using data from the Scanian Economic Demographic Database for women born between 1813 and 1898, this work studies the impact of exposure to insufficient nutrition while in-utero or to epidemics in the first year of life on offspring sex ratios at birth. We find that women of low socioeconomic status who were exposed in infancy to whooping cough give birth to a lower proportion of boys, probably as a result of a higher incidence of spontaneous abortions. Infant mortality is also higher for offspring born to women exposed to epidemics, and because of gender specific fetal mortality, it is lower for males in comparison to females.