Three minor fast days were decreed by the sages to commemorate critical events leading up to the destruction of the First and Second Temples and the dispersion of Jews into exile. Pregnant women are exempt from fasting on these fasts: Tzom Gedaliah, the Tenth of Tevet, and the 17th of Tammuz.
There is a difference of opinion as to whether a pregnant woman who feels well should try to fast even though she is not required to. The Rema seems to indicate that the custom is to fast if it is not too difficult for her. However, the Mishneh Brura states that a pregnant woman who feels any weakness should not fast.
In addition, Ta’anit Esther is observed just before Purim in commemoration of the days on which the Jews defended themselves from their enemies. Pregnant women do not fast on Ta’anit Esther, which is the most lenient of the communal fast days.
A woman within 30 days of childbirth or of pregnancy loss (at least forty days post-conception, usually calculated from immersion), has the halachic status of yoledet (a woman who gave birth) and does not fast on minor fast days.
A woman who experienced a miscarriage within 40 days of conception may be exempt as a cholah (a person who is ill), depending on her medical condition.
A woman more than 30 days after a miscarriage who is concerned about fasting should consult her physician and a halachic authority.
According to many authorities, the laws of a breastfeeding woman apply for two years after childbirth even when a woman is not actually nursing (or pumping). Please see here for a detailed discussion.
There are two major fast days on the Jewish calendar. Unlike the other fasts, which last from dawn to dusk, these fasts are a little over 24 hours long, and their rules are more stringent.
The fast of Yom Kippur is a Torah obligation (Vayikra 16:29 and 23:27) and is the most stringent of the fast days. Tisha B’Av marks the anniversary of the actual destruction of both Temples. Therefore its halachot are more stringent than the other rabbinically-ordained fasts, but less so than those of Yom Kippur.
There are different opinions regarding the exact circumstances under which pregnant women should fast on Yom Kippur and Tisha B’Av. Many poskim, including the rabbinic supervisors of this website, rule that a woman during a low-risk uncomplicated pregnancy should fast if she feels no unique difficulty. However, there are minority opinions that are more lenient, and each woman should consult her own halachic authority.
Medically, not much study has been done on the effect of fasting on pregnancy. One published article showed increased delivery by women the day after Yom Kippur. Another showed an increase during the end of Yom Kippur as well. In both studies, however, most of the deliveries were at term. There is not much evidence that fasting will cause preterm labor, at least in low-risk pregnancies. Thus, medical literature is consistent with the instruction that healthy pregnant women should fast. Even so, drinking plenty of fluids for a few days before the fast is recommended.
Halacha and medicine are both case-based. A pregnant woman should consult in advance with her physician about fasting and about when to break a fast. This is especially critical if she has any complications or risk factors. It is important that the physician (even if not religious or non-Jewish) be sensitive to the seriousness of this fast and give a well-considered response. The woman should then discuss any medical concerns with a halachic authority.
Because fasting on Yom Kippur is a Torah obligation, it takes precedence over attending synagogue. (A woman’s fasting even takes halachic precedence over her husband’s attending synagogue.) On Tisha B’Av as well, fasting takes precedence over either spouse’s synagogue attendance.
If it will help her to keep the fast, a pregnant woman should plan on spending the day in bed, resting and praying on her own.
A woman who needs to break her fast should have in mind while eating that she is fulfilling the mitzva of “v’chai bahem,” living for the sake of Torah (and not risking life).
Some physicians have raised the concern that a woman fasting near term might begin labor dehydrated. Others maintain that, if such a situation were to arise, it could quickly and easily be alleviated. A woman who will be near term on a major fast day should consult with her own physician and halachic authority about the implications for her.
From the onset of labor, a woman becomes a yoledet and is considered a cholah sheyesh bah sakanah, an ill person who is at risk. A woman in labor is certainly halachically permitted to eat and drink. However, the advisability of eating and drinking during labor is a matter of medical debate, so each woman should consult with her health care provider.
For the first three days after childbirth, a woman is considered a cholah sheyesh bah sakanah, an ill person in danger, and is not allowed to fast even on Yom Kippur. For the next four days, she is still exempt from fasting.
A woman who will be more than seven days postpartum on Yom Kippur should consult her physician and a halachic authority about the fast.
A woman may not fast on Tisha B’Av during the first three days after giving birth. She should not fast during the first week, and is exempt from fasting on Tisha B’Av for the first thirty days postpartum.
These halachot also apply to a woman following a pregnancy loss after at least 40 days gestation, calculated halachically from conception (assumed to be mikveh night unless a different date can be clearly identified). A woman who experienced an earlier miscarriage and is concerned about fasting should consult her physician and a halachic authority.
A woman more than 30 days following birth or pregnancy loss who is concerned about fasting should consult her physician and a halachic authority.
For information on fasting while undergoing fertility treatments, please see Fertility Treatments & Fasting.
Shiurim (Minimum Quantities) on Yom Kippur
The prohibition against eating or drinking on Yom Kippur extends even to tiny amounts. However, the penalty for violating this prohibition applies only if a certain quantity (shiur) of food or drink is consumed. Therefore, one for whom fasting is dangerous is instructed not to fast, but in some cases can mitigate the act of eating or drinking by having less than a shiur at one time.
The shiur for drinking is half of one mouthful (measured before the fast by filling the mouth and cheeks with liquid, emptying it into a measuring cup, and halving that). If eating is necessary, a woman may eat up to 30cc at a time. Ideally, these quantities should be consumed at intervals of at least nine minutes; however, opinions vary and some authorities permit intervals as short as four minutes.
Tisha B’Av on Sunday
If Tisha B’Av falls on a Sunday, one should recite havdala before eating, or before drinking beverages other than water.
There are different opinions regarding a Tisha B’Av nidcheh, when the fast is postponed from Shabbat to Sunday. We follow the position that a healthy pregnant woman should attempt to fast on a Tisha B’Av nidcheh. However, the fast should be treated with greater leniency than in other years and she may begin drinking or eating as necessary at the first sign of feeling unwell.
Practical tips for fasting during pregnancy include:
- Drink plenty of fluids for a number of days before the fast.
- It is more important to stay home and fast than to break your fast and attend synagogue. It is also more important for you to fast than for your husband to attend synagogue.
- Discussion should take place prior to the fast about family arrangements (e.g., husband staying home a few hours, hiring a babysitter) that can help make it easier.
- Remember to ask your healthcare provider about fasting at a regularly scheduled prenatal appointment at least a few weeks before the fast.
- Before the fast, discuss with your healthcare provider and a halachic authority what circumstances would warrant breaking the fast, and (for Yom Kippur) in what circumstances this should be limited to shi’urim.