[thebiss]

There have been recent studies on the impact of fasting during pregnancy. Here's two:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8377932/ > A total of 215 women were included in the study, 123 women fasted, and 92 women did not fast. Only 2.8% of women knew that fasting is forbidden in pregnancy. Sixty five percent of women reported weakness as the main reason for not fasting. The rate of gestational diabetes, pregnancy induced hypertension and preterm delivery was higher among women who fasted (17% vs 14%, 7% vs 2%, 9% vs 9%) respectively, compared to non-fasting women, but were not found statistically significant. There was no difference in anthropometric measurements of newborn, among both groups.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9931121/ > Fasting during pregnancy was associated with reduced birthweight, in particular for fasting during the first trimester (-352ˑ92g, 95% CI: -537ˑ38; -168ˑ46). Neither dietary composition nor altered sleep were directly associated with birthweight. However, dietary composition during Ramadan outside of fasting hours seems to moderate the fasting-birthweight association, which disappeared for women switching to high-fat diets.