Are Pregnant Women Obligated to Fast on Religious Fast Days
opinion of Rabbi Moshe Zuriel
Many Rabbis are questioned by pregnant women if they are obligated to fast on Yom Kippur and other fast days, such as Tisha B'Av. These women fear that fasting may lead to miscarriage or premature birth, with its consequent damages to the infant.
A respected rabbinic authority in Israel, Rabbi Israel Fisher, permitted pregnant women to eat and drink during Yom Kippur, if limited to small amounts, 30 grams of solids (about one ounce) and 40 grams of liquids, if no more than that is taken during any nine minute period. This can be done again and again at proper nine minute intervals. The reason for this, he claimed, is that to his knowledge tens of pregnant women doing this fast, had miscarriages. We know that Pikuah Nefesh, even of a fetus, takes priority over fasting.
Many prominent rabbis disagreed with this permissive ruling, citing the Shulhan Arukh which specifically prohibits eating or drinking anything on this day, even for pregnant women.
Rabbi Moshe Zuriel, a highly respected rabbinic scholar in Israel, has written an article in which he supports the view of Rabbi Fisher. Rabbi Zuriel checked with medical authorities and found that Rabbi Fisher is right!
Statistics gathered by the Siroka Hospital (Be-er Sheba) were drawn from the past twenty three years dealing with 744 births. The study (http://dx.doi.org/10.3109/14767058.2014.954998) has revealed that the risk factor was significantly higher among those Jewish women who were fasting on Yom Kippur. In cases of premature birth before 37 weeks of pregnancy, the percentages of death of the fetus were 75-80 percent. Premature births also face problems relating to proper lung development, damage to the nerve system, stomach problems, sight and hearing problems.
In the Hebrew article that was published in the Israeli Techumin (volume 37, pages 71-81), Rabbi Zuriel cites a prominent Halakhic authority, Havot Yair who ruled that eating less than the prohibited quantity (Shi-ur akhila) is only Rabbinically prohibited. Therefore, if a pregnant woman feels weak and unable to fast the full day, she should be permitted to eat and drink less than the prohibited quantity.
Rabbi Zuriel cites other halakhic authorities who concur with Rabbi Fisher's ruling. The halakha calls for leniency when there is a doubt concerning saving human life. Pregnant women who feel great weakness due to the fast and had no chance to ask their doctor's advice before the fast day, and during the fast day have not the ability to ask their rabbi, should eat and drink the modicum amounts aforementioned at no less than nine minute intervals. It is advised that pregnant women consult their doctor and rabbi prior to the onset of a fast day, in order to determine what is best in their own specific case.