Health Capital and the Prenatal Environment: The Effect of Ramadan Observance During Pregnancy

This paper uses the Islamic holy month of Ramadan as a natural experiment in diurnal fasting and fetal health. Among births to Arab parents in Michigan, we find prenatal exposure to Ramadan results in lower birth weight. Exposure in the first month of gestation also reduces the number of male births. Turning to long-term "fetal origins" effects, we find Muslims in Uganda and Iraq are 20 percent more likely to be disabled as adults if early pregnancy overlapped with Ramadan. Estimated effects are larger for mental (or learning) disabilities. Our results suggest that relatively mild prenatal exposures can have persistent effects.