During Ramadan, which lasts about a month, adult Muslims abstain from food and drink during daylight hours, but they can eat during the dark hours.
The meals that Muslims eat after sunset during Ramadan contain more fat and simple carbohydrates than regular meals eaten outside of Ramadan. In addition, the sleep pattern of a pregnant woman changes, as cooking and eating is postponed to a later time of day.
Scientists conducted a survey of 326 women whose pregnancy fell on Ramadan in 2017. So, 98 observed Ramadan, 46 of them completely refused food for a period of at least 20 days. The authors analyzed their medical records and those of their children, and compared them with information about those who did not fast.
As it turned out, the weight of newborns from mothers who observed Ramadan, on average, was 158 grams less. If the mothers fasted in the first trimester of pregnancy, the difference was 353 grams.