Disease exposure in early life affects women’s reproductive outcomes: Evidence from southern Sweden 1905-2000

Mounting evidence shows that early-life adversity negatively affects morbidity and survival in late life, but knowledge is limited about effects on health in mid-life. To deepen our understanding of the long-term consequences of disease exposure in early life, we study women’s reproductive outcomes and survival. Using the Scanian Economic Demographic Database (SEDD) and Swedish administrative register data, in combination with local infant mortality rates as an indication of disease load exposure in the year of birth, we follow women’s reproductive careers over close to a century (1905-2000), focusing on a comprehensive set of outcomes. The results show that women exposed to disease in early life give birth to a lower proportion of boys (lower offspring sex ratio), in line with the notion that male fetuses are more vulnerable to their mother’s adverse physical or contextual conditions, and that pregnancies with male fetuses more often result in a miscarriage. Moreover, boys of exposed mothers are more likely to be born preterm, and they are heavier than boys born to non-exposed mothers, possibly because of in utero out-selection of weaker male fetuses. We also note that exposed women have a higher risk of stillbirth and miscarriage, and a lower risk of multiparous pregnancies, but do not find strong evidence that overall likelihood of giving birth is affected. Our results imply that early-life disease exposure has a continuous impact on reproduction and health across the female life course, and even affects the early-life health of the next generation.