Disease exposure in infancy affects women’s reproductive outcomes and offspring health. Evidence from southern Sweden 1905-2000

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