Mechanisms linking prenatal environment and linear growth: the case of Ramadan during pregnancy.

Despite established links between prenatal nutritional deprivation and impaired offspring growth, the underlying dynamics and potential moderators remain largely unexplored. This study investigates the dynamics underlying Ramadan during pregnancy and its associations with children's linear growth, using data from the Indonesian Family Life Survey (1993 - 2015). We exploit Ramadan during pregnancy as a natural experiment, separating exposure from maternal background characteristics and season of birth effects. Employing OLS and logistic regressions, we explore two key mechanisms predicted by medical theory. First, the realization of health impairments in response to prenatal shocks is influenced by postnatal circumstances. Our results reveal significant growth impairments primarily in children raised under poor sanitary conditions, which is a risk factor for diminished linear growth by itself. Secondly, we assess whether prenatal Ramadan prompts epigenetic shifts towards earlier reproductive activity, potentially at the expense of height growth. Our data shows that prenatally exposed women tend to have their first childbirth at a younger age, though menarche onset remains unaffected. These results suggest that postnatal environments play a crucial role in mitigating sensitivity to prenatal shocks, highlighting the critical need for favorable living conditions for all children.