It is not without consequences for the offspring when pregnant women fast. On average, affected children are somewhat lighter as adults.
Ramadan in the Indonesian capital Jakarta. Photo: dpa
"I’m eating for two," expectant mothers often justify their great desire to eat during pregnancy. And they are right: the daily need for energy is higher during pregnancy. But what happens when pregnant women do not eat at all for a period of many hours, such as during the fasting month of Ramadan?
Epidemiologist Reyn van Ewijk from the University of Mainz asked himself this question – and traveled to Indonesia to find answers. Indonesia is the country with the largest number of Muslims in the world: 86 percent of the approximately 250 million Indonesians are of the Islamic faith.
For pregnant Muslim women, Islam makes an exception to the sacred duty of fasting: they may, if they wish, refrain from fasting. However, they must make up the fast, "preferably in the year before the next Ramadan," as the Central Council of Muslims in Germany explains. Worldwide studies have shown, however, that 70 to 90 percent of pregnant Muslim women observe the fasting month like all other Muslims.
Van Ewijk evaluated data from 12,900 Muslims in Indonesia. He compared such Muslims who had been "in utero" (i.e., in their mother’s womb) during Ramadan with Muslims whose mothers had not fasted during pregnancy.
He found that adult Muslims and Muslim women whose mothers had fasted during pregnancy were on average 0.85 kilograms lighter than the unexposed, that is, the children of women who did not fast.
It is interesting to note that children who were also conceived during Ramadan are not only lighter later in life, but also smaller: They reach a height that is, on average, 0.8 centimeters shorter than those whose conception did not occur during the fasting period.
Admittedly, the differences do not appear particularly large. Statistically, however, the difference is significant. This means that the probability that the differences are due to chance is very small.
Van Ewijk also found evidence that the general health of those exposed was worse, and symptoms of coronary heart disease and diabetes were also more frequent.
These results can be explained on the one hand by the fact that pregnant women have a higher energy requirement overall. With the two meals in the evening and at night, the total daily requirement of nutrients cannot always be met.
In addition, older studies have shown that pregnant women are subject to a process called accelerated starvation: If they skip meals, certain blood levels are comparable to those of starving women. This can lead to a slowdown in cell division in the organs of the unborn child and thus to delayed maturation.
However, no general statements or even instructions for action should be drawn from his study, van Ewijk said. The findings relate only to Indonesia and are too unspecific, he said. After all, there is no telling whether the same study would produce similar results in Germany or in other countries.
Nor did it matter in van Ewijk’s study what kind of food the pregnant women ate when breaking their fast. However, the question of whether they ate white bread, brown bread, sweets, fruit or vegetables could have an influence on the results. Nevertheless, the study offers interesting clues that could be followed up by further studies. After all, fasting is not only practiced in Indonesia.