Ramadan during pregnancy: effects on health and fertility across the generations

• Applicant: Professor Dr. Reyn van Ewijk
• Subject Area: Epidemiology and Medical Biometry/Statistics ; Nutritional Sciences ; Public Health, Healthcare Research, Social and Occupational Medicine ; Statistics and Econometrics
• Term: since 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 260639091

The evidence on health effects of Ramadan during pregnancy along the offspring’s life course was scarce when our work on the original project started. Our research has contributed to a body of knowledge on the effects of Ramadan during pregnancy along the entire life course, from health at birth to later adulthood. Moreover, we found that many pregnant Muslims in Germany adhere to the Ramadan fast, which underlines the public health relevance of this research also in countries with minority Muslim populations. Worldwide, a majority of pregnancies of Muslim women overlap with a Ramadan and a high share of pregnant Muslims fast, thereby exposing substantial numbers of Muslims to Ramadan fasting in utero. Further research is therefore highly relevant, as a full understanding of how Ramadan during pregnancy exerts effects on the offspring is necessary for Muslim women to make well-informed decisions, and for health care workers to give well-founded advice. One particularly noteworthy finding of our previous work is that our results suggest that prenatal exposure to Ramadan might lead to epigenetic changes. We found indications that phenotypes with an altered fertility, in particular with rapid maturation, may emerge in response to prenatal exposure to Ramadan. It might be that the fertility window of the exposed are shifted to a younger age, as a response to the increased high mortality pressure that is induced by prenatal exposure to Ramadan. From research on other types of prenatal exposures, there are indications that such epigenetic adaptations may indeed occur, yet nothing is to date known about this from the context of Ramadan. Research on other prenatal exposures has also shown that epigenetic changes can carry over to subsequent generations and Ramadan during pregnancy provides a unique opportunity to study this phenomenon in response to a comparatively mild prenatal shock. Given our background, we do not plan to do biomedical research into these epigenetic changes themselves. Rather, we focus on the outcomes and effects that span across large population groups.The research proposed in this renewal proposal consists of two main projects. First, we study the implications of potential epigenetic changes caused by in utero exposure to Ramadan on human reproduction, focusing on whether the fertility window shifts (as expressed by earlier menarche / later menopause, or an earlier age at first childbirth), as well as on altered completed fertility (number of children over lifetime). Second, we study the implications of epigenetic changes on the subsequent generation, i.e. we analyze whether health outcomes of the grandchildren generation are affected, for instance focusing on health at birth or cognitive test scores. If we indeed find effects on fertility and transgenerational health outcomes, the consequences of Ramadan observance during pregnancy may be even more far-reaching than is currently thought, and span across more than one generation.

• DFG Programme: Research Grants