Ramadan during Pregnancy – Fasting, Nutrition, Sleep Patterns and Offspring Health at Birth

Background Intrauterine exposure to Ramadan is associated with adverse offspring health outcomes. Yet, the dynamics behind these associations remain largely unexplored. We investigate if maternal intermittent fasting or other lifestyle changes during Ramadan affect birth outcomes, and determine whether nutritional and sleep behavior during non-fasting hours influences the fasting-birth weight association. Methods Linear regressions are estimated using OLS to identify the associations between fasting, sleep behavior, sweets consumption and birth weight, 5-minute APGAR score and gestational age. Interaction terms between fasting and other behaviors are included to explore the potential moderating role of behaviors beyond the binary fasting decision. The Oster test statistic is calculated to address the possibility of residual confounding. Findings Newborns with intrauterine exposure to fasting had lower birth weights than non-exposed newborns (-161ˑ57g, CI: -295ˑ63; -27ˑ51). No associations with APGAR score (0ˑ02, CI: -0ˑ23; 0ˑ27) and gestational age (0ˑ00, CI: -0ˑ51; 0ˑ51) appeared. Sweet food consumption and sleep reduction themselves are not associated with birth outcomes. However, consuming more sweet and fatty foods mitigates the negative fasting-birth weight association. The Oster test statistic shows that results are not subject to residual confounding. Interpretation Fasting seems to be the main driver of the negative fasting-birth weight association, while simultaneous nutritional and behavioral changes appear to influence how the effects materialize. Nutrition is a potential mitigating factor that should be taken into consideration when advising Muslim women of childbearing age on their behavior during Ramadan. Funding This research was funded by the German Research Foundation (DFG grant 260639091).