Does prenatal Ramadan exposure affect child growth?

Conflicting results over the effect of prenatal Ramadan exposure on child growth have been resolved in a recent study, which restricted samples to multifaith regions and accounts for growth faltering.

The authors replicated counterintuitive findings in the full sample comprising 1,277,535 children. Prenatal Ramadan exposure showed no substantial impact from ages 0 to 2 years in the 10 percent to 90 percent Muslim multifaith sample (n=583,790).

The negative effects appeared from 3 years of age onward. The total effect on Muslim children compared with nonexposed participants was ‒0.06 z-score points at age 3 (p=0.033) and ‒0.1 at age 4 (p<0.001). Compared with non-Muslim children, the differential effect at age 4 was ‒0.08 z-score points (p=0.020).

These results persisted in the 15 percent to 85 percent sample (n=436,905; ‒0.1 z-score points at age 4; p=0.02), with no false effects on non-Muslim children.

“Further research is needed to disentangle the specific pathways, including fasting, dietary changes, hydration, and sleep disruption, through which Ramadan exposure affects foetal development, in order to inform targeted public health guidance,” the authors said.

This study used demographic and health survey (DHS) data to conduct a difference-in-difference intention-to-treat analysis. Ramadan exposure was defined as the proportion of Ramadan overlapping with the child’s time in utero, regardless of whether the mother fasted, avoiding bias from selective fasting behaviour.