New Research on the Fetal Origins Hypothesis
This session on fetal origins explores the effects of conditions in utero, at birth, and early in childhood. In “Health in Utero, Parental Investment, and Human Capital Development,” Elaine Hill and David Slusky use Colorado birth certificates matched to schooling outcomes to investigate the relationship between birth weight, birth spacing, and educational attainment. They find that birth weight results in higher test scores, birth spacing decreasing the first child’s test scores but increases those of the second child, and that there is a negative effect of birth spacing on the second child’s birth weight. In “Cesarean Section, the Gut Microbiome and Children’s Health: Investigating Causal Linkages,” Jason Fletcher and Jessica Polos combine twenty years of birth data from the National Survey of Children’s Health with state-level cesarean section rates and model the effects of cesarean section on rates of food allergy, asthma, and attention-deficit disorder, controlling for state and year fixed effects. Additionally, they measure the racial, socioeconomic and geographic differences in these relationships. In “Worth the Wait: The Effect of Early-Term Birth on Maternal and Infant Health,” Kasey Buckles and Melanie Guldi document a rise in early-term births in the US from 1989 to the mid-2000’s, followed by a decline which cannot be attributed to demographic changes. They posit that this decline has been driven by changes in medical practice. Exploiting county-level variation in the timing of the changes in medical practice, they show that early-term inductions lead to lower birth weights and an increased risk of birth injury.