Short-term fetal nutritional stress and long-term health: Child height.

OBJECTIVE

This study examined the impact of in utero exposure to Ramadan, the Islamic fasting month, by trimester on height at ages 0 to 18 for a sample of children from Tehran, Iran. If exposure to Ramadan is associated with significant nutritional stress to the fetus, the fetus's adaptive responses to nutritional insufficiency could manifest as changes in height during childhood, long before any effects on aging or disease risk at older ages.

METHODS

Children who were exposed and not exposed to Ramadan in utero were compared to identify any systematic difference between their parents' and households' characteristics (including height, age, education, and indicators of wealth). Also, the seasonal pattern of food consumption in Tehran was analyzed. Finally, the association of child height with prenatal exposure to Ramadan was measured, controlling for seasonality and parent and household.

RESULTS

Ramadan associated fasting in the second trimester of gestation was associated with 0.091 age-adjusted SDs (ie, 0.60-0.67 cm) decrease in children's height at age 10 years or older. The negative association was largest in male children and was approximately 1 cm at age 12 years or older among male children.

CONCLUSION

Maternal Ramadan fasting in the second trimester, the critical period for long bone development, was associated with decreased height. Exposure to ritual fasting is important because approximately 75% of all Muslim children are exposed to Ramadan in utero.