Exemptions from Major Fasts
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Exemptions from Major Fasts
By Debbie Zimmerman and Laurie Novick
Must all women fast on Yom Kippur and Tish’a Be-Av? What if a woman is pregnant, postpartum, or nursing? How do the laws of the two fast days differ?
Fasting creates an opportunity to transcend our physicality and focus on teshuva (see more here). Even so, it is not obligatory for everyone. In our discussion of minor fasts, we defined three groups of women who may have special halachic status with respect to fasts:
- Me'uberet: a pregnant woman
- Yoledet: a woman in childbirth and up to 30 days postpartum (or following a pregnancy loss that occurred after forty days from conception)
- Meineket: a nursing woman (for the minor fast days, this might include any woman within 24 months of giving birth)
We also raised some of the medical questions fasting presents for these women, though the scientific literature is scanty and largely inconclusive. Next, we learned that women in these categories are generally exempt from fasting on minor fast days.
On Yom Kippur and Tish'a Be-Av, however, an otherwise healthy me'uberet or meineket is expected to fast:
Rava taught: Pregnant and breastfeeding women fast the full day on [Tish’a Be-Av] as they fast the full day on Yom Kippur.
Pregnancy and nursing do not in themselves exempt women from the major fast days. Nevertheless, a person who is ill (choleh) may be exempt from fasting on Tish’a Be-Av and even on Yom Kippur, depending on the nature and severity of the illness. In some situations, a me'uberet, yoledet, or meineket is herself considered ill or endangered, or the fetus or nursing baby might be, with implications for the halachot of fasting.
To understand how this principle is applied, we need first to clarify how the main categories of illness recognized by Halacha relate to the obligation to fast.
I. Choleh she-yesh bo sakana or safek sakana A choleh she-yesh bo sakana is a person who is so ill, weak, or injured that their life is clearly in danger. A case of safek sakana refers to a situation in which we are uncertain whether the person’s life is in danger or not.
Preservation of human life, piku'ach nefesh, is a major halachic principle, according to which we are nearly always prohibited from allowing halachic observance to endanger life.
And you shall keep My statutes and My laws that a person shall do them and live by them, I am God.
“And live by them” – and not die by them
The Talmud not only prohibits a person from fasting, even on Yom Kippur, when it presents a mortal danger, but also when it only presents the possibility of mortal danger:
There is doubt concerning matters of life and death, and with a doubt concerning matters of life and death, we rule leniently
Shulchan Aruch codifies this law with respect to fasting in the case of a physician who is familiar with someone's illness and not sure whether fasting will endanger them:
Shulchan Aruch OC 618:5
If the sick person says that he doesn’t need, and the physician is uncertain, we give him food
Furthermore, even when fasting may only lead to a medical condition that is dangerous, that, too, provides grounds for exemption from fasting on Yom Kippur:
Responsa Iggerot Moshe OC III:91
In my humble opinion, since this disease that he has will cause him to become ill with another life-threatening disease, this disease should also be considered life-threatening, even if we know that if he does not become sicker, this [current] disease is not life threatening. Since, if he does not recover from this disease, it is possible that he will be endangered by a different disease, then this disease automatically on its own endangers the patient.
II. Choleh she-ein bo sakana Often just called a "choleh", this is a person who cannot function because of illness, or for whom fasting will lead to inability to function. For example, someone suffering from a severe, debilitating migraine or for whom migraines are triggered by fasting, would fit into this category.
Ramban teaches that a choleh of this sort is exempt from all rabbinic-level fasts, including Tish’a Be-Av.
Ramban Torat Ha-adam
…A sick person who needs to eat, do[es] not need to be assessed by a professional. Rather, we immediately give them food, as the rabbis did not include the sick in their decree.
Halachic consensus follows Ramban.
III. Meichush Be-alma This is a minor illness, where a person doesn't feel well, but on the whole can manage to function. Someone with an ordinary headache or fatigue, whether going into the fast or on account of it, would typically fit into this category, even if they need to lie down for a while. A person who has a meichush be-alma is usually fully obligated to fast.
Aruch Ha-shulchan summarizes:
Aruch Ha-shulchan 554:7
…If he is bedridden he does not fast even on Yom Kippur, for anyone who is bedridden is in [mortal] danger, as is established in Shabbat 32a… but people who are just minorly ill must fast. The general rule is: Anyone who is considered sick does not fast on Tish'a Be-Av, and anyone who is not considered sick does fast.
In short, a choleh she-yesh bo sakana never fasts, even if the sakana is uncertain or indirect. A choleh she-ein bo sakana fasts only on Yom Kippur, when fasting is a Torah-level obligation, but not on Tish'a Be-Av or minor fast days. Someone who doesn’t feel well but is able to function overall (with a meichush be’alma) typically fasts.
Sometimes, a person’s behavior can determine which, if any, of these categories they fit into. For example, someone who goes into a fast well-hydrated, and arranges to spend the fast in a cool and comfortable place, may be able to avoid becoming dangerously ill. Moreover, a person whose ability to fast depends on staying home should remain at home rather than attend tefillot.
Responsa Chatam Sofer VI:23
It is implied that when they are confined at home the fast does not harm them. If so, they should fast and be confined [at home] and pray alone and they should not read the Torah for this is not sufficient to push away a Torah-level prohibition with the penalty of karet.
Similarly, a person who can fast only if spending the day resting, and who is normally responsible for young children, should arrange for someone else to care for the children on the fast day. If necessary, it is better for a spouse to tend to the children rather than attend tefillot, when that will enable the other spouse to rest and fast. Rav Moshe Sternbuch emphasizes this in the case of a pregnant woman with young children:
Responsa Teshuvot Ve-hanhagot 2:292
Today, it is proper for a pregnant woman who is concerned that she will feel weak, or with any choleh she-ein bo sakana, that they be careful not to make any strenuous effort at all on Yom Kippur, especially with caring for her children, but she should rest and lie down. The husband should be quick to occupy himself with this [childcare] and in this type of arrangement she generally won’t feel special weakness and will be able to fulfill the mitzva of the day [fasting] as is fitting.
In the above cases, assessment (umad) of a person's physical state is typically entrusted to a team: the person at risk together with their physician, under the guidance of a halachic authority. In this way, decision-making integrates halachic and medical expertise with the experience of the choleh.
Based on a Talmudic discussion of umad on Yom Kippur, Halacha generally calls for such decisions to err on the side of caution for health:
Rav Yanai said, If a sick person says he needs [to eat or drink], and the physician says he doesn’t need, we listen to the sick person. What is the reason? “The heart knows the bitterness of its soul” (Mishlei 14:10) ... If the physician says he needs, and the sick person says he doesn’t need, we listen to the physician. What is the reason? It is confusion that took hold of him [the sick person].
Shulchan Aruch rules accordingly.
In complex cases, it is preferable to seek the opinion of a religiously observant physician, whose words are granted more halachic credence. In other more pressing situations, people may need to make their own decisions on the spot.
Once assessed as a choleh who must break the fast, a person may not be “stringent” and fast, since this is being lenient on the Torah's mitzva of "piku'ach nefesh." People who nevertheless fast are considered personally responsible for risking their lives, and their fasting is not considered a mitzva.
Mishna Berura 618:5
The poskim wrote that if the sick person wants to be stringent even if he needs this [to break the fast], it is said of him: “I will demand your blood for your souls.”
On the whole, anyone with medical concerns about fasting should take the following steps:
- Consult with a physician (and a pediatrician if relevant for a nursing baby), discuss any concerns well in advance of the fast, and clarify what signs to watch out for.
- Discuss the physician's response with a halachic authority, including whether it is medically permissible to fast, the conditions under which the fast should be broken, and whether drinking or eating in shi’urim (see below) will be sufficient.
- If given permission to fast, take care to drink more (and for nursing women, perhaps pump to have extra milk on hand) over the days before the fast.
- Make plans to enable a full day of rest in a comfortable space on the fast day itself, and leave time to recuperate as necessary the next day as well. Nursing mothers in particular should plan to spend the day after the fast resting and breastfeeding frequently to rebuild their milk supply.
- If instructed to drink or eat in shi’urim, prepare a nourishing liquid in advance of the fast and "measure" in advance how much to eat or drink at each interval.
Let's look at how the question of who is exempt from fasting on Yom Kippur or Tish'a Be-Av due to illness comes to bear on women, specifically the me'uberet, yoledet, and meineket.
Yom Kippur and Tish'a Be-Av
Danger to a fetus in utero is equivalent to the situation of choleh she-yesh bo sakana:
Sefer Halachot Gedolot 13, Hilchot Yom Ha-kippurim
A pregnant woman, if we know that if she doesn’t eat her fetus will be uprooted, and even though we say it is doubtful whether it is viable or not, it is correct to give her [food]….
Ramban compares breaking the fast to save a fetus to performing prohibited labor on Shabbat for it. He adds that this halacha applies even at the embryonic stage.
Ramban, Torat Ha-adam Sha’ar Ha-michush – The Matter of Danger
As [Behag] said, because of danger to the offspring as well, we derive from this that even if there is no concern for her [the mother], we violate…in the matter of keeping mitzvot, we violate for her. The Torah said violate one Shabbat for him, and perhaps he will keep many Shabbatot. Therefore, even with saving a fetus less than 40 days [from conception], who has no [independent] life at all, we violate for him in accordance with the opinion of the Ba’al Halachot.
In pregnancy, Rashi notes, a woman's health and her fetus's are intertwined.
Rashi Yoma 82a
If she does not eat, both of them are in danger.
A woman in a high-risk pregnancy is thus often treated as a chola she-yesh bah sakana, regardless of whether she requests food or displays signs of distress. For example, a me'uberet who has been bleeding, has abdominal pains or contractions, or has a history of miscarriages or preterm labor should not fast. Similarly, a woman undergoing fertility treatments should not fast during the first weeks of pregnancy, until a heartbeat has been detected. Women at other stages of fertility treatments, particularly when undergoing ovarian stimulation, may also be instructed not to fast.
Pregnancy Without Complications
Although a healthy pregnant woman with no known pregnancy complications is expected to fast, the Mishna recognizes that her fasting may be dangerous in some cases. It thus introduces the discussion of piku’ach nefesh on Yom Kippur with the example of a pregnant woman who experiences a strong urge to eat when she smells food.
Mishna Yoma 8:5
Mishna: A pregnant woman who smelled [food and has a strong urge for it], we give her food until she is calmed. We give a sick person food at the direction of experts, and if there are no experts there, we give him food at his own direction until he says enough.
Indeed, Shulchan Aruch rules that a me'uberet who enters the fast in good health but insists upon eating is given food until she becomes calm.
Shulchan Aruch OC 617:12
A pregnant woman who smells [food] (Rema: and her face changes even if she does not say, I need [to eat]), we whisper in her ear that it is Yom Kippur, and if she is calmed with this reminder – good, if not we give her food until she is calmed.
Halachic authorities have discussed contemporary applications of a pregnant woman making an assessment for herself about fasting during Yom Kippur. Rav Moshe Harari reports that Rav Avigdor Nebenzahl rules that a me'uberet should drink in shi’urim (again, see below) without delay or need for consultation if she experiences dizziness or nausea from the fast. However, he also reports that Rav Mordechai Eliyahu disagrees:
Rav Moshe Harari, Mikra'ei Kodesh 9 n. 27
Rav Avigdor Nebenzahl told me that if a pregnant woman feels unwell, one need not whisper to her, and therefore if she feels dizziness, even mild dizziness, she must drink. If shi’urim suffice for her, she should drink in shi’urim. And if not she should drink as necessary. This is because she is pregnant and there is no need to be stringent with her…Some time later I asked Rav Mordechai Eliyahu about these matters. And after he read what we wrote in the name of Rav Nebenzahl (above) in the matter of a pregnant woman with dizziness or nausea on account of the fast, he said that in his opinion this is not the halacha…
In a controversial ruling, Rav Yisrael Ya'akov Fischer maintains that even a woman with a typical pregnancy with no known complications may not fast on Yom Kippur, because a significant number of women miscarry following the fast, and because piku'ach nefesh is concerned even with minor possibilities:
Responsa Even Yisrael VII:36:4
For the generations have become weak, and tens of women who have fasted have miscarried following the fast. We don't need to also ask a physician, and it is clear that it is prohibited to fast on Yom Kippur…And we maintain that "in matters of piku'ach nefesh we don’t follow the majority" [of cases, but rather are concerned for a minority].
This ruling was echoed by Rav Nahum Rabinovitch, who exempted pregnant women between five and nine months from fasting.
Many rabbis, prominently Rav Eliezer Waldenberg, vociferously disagree with this type of approach, for several reasons: Torah law is at stake; our sages have ruled to the contrary; and thousands of pregnant women fast seemingly unharmed. To prevent danger, women who feel weak may— and should— pursue individual halachic rulings.
Responsa Tzitz Eliezer 17:20 (4)
Behold in my opinion it is a very great leniency to issue a general ruling permitting pregnant women to eat on Yom Kippur based on the consideration that "the generations have become weak," and not just to permit [eating] but to require it…In contrast to what he writes about tens of women who miscarried on account of the fast, we know in contrast from every single place about hundreds and thousands of pregnant women who fast on Yom Kippur and don’t miscarry, God forbid. How can we because of some tens of incidences of women miscarrying…who are a minority of a minority, come on that basis to uproot great, established halachot in this matter to obligate fasting in the Talmud, Rambam, and Shulchan Aruch with no dissenter, and to establish because of this based on our own judgment that nature has changed with this?...Therefore in my opinion the matter is clear in accordance with halacha that one should not issue a general permission, and how much more so that one should not require them to eat, but rather one should instruct them that in every case of weakness or divergence from the normal situation, they should ask a question of 'a wise man who will teach them the way in which to go' in accordance with the situation that becomes clear to him in the specific case of the questioner.
In the past, some halachic authorities ruled that a woman nearing term should nearly always fast, since delivery at that stage would not be significantly premature and thus present less of a risk to her and her baby. Those rulings have faded in light of increased understanding that dehydration presents a danger to a woman during labor.
Further Leniency on Tish'a Be-Av
As we learned above, if a me'uberet feels sick on the level of a choleh she-ein bo sakana, then she is exempt from fasting on Tish'a Be-Av. Aruch Hashulchan takes this ruling a step further. He maintains that a me'uberet or meineket is exempt from the fast even if she is not yet sick, but merely feels weak and liable to become sick:
Aruch Ha-shulchan OC 554:7
Pregnant and breastfeeding women – fast the entirety of Tish’a Be-Av, as they fast the entirety of Yom Kippur. And even on Tish’a Be-Av, if they are weak and close to falling ill, even without danger – they should not fast. … as the rabbis did not decree for the sick…The general rule is: Anyone who is considered sick does not fast on Tish’a Be-Av, and anyone who is not considered sick does fast. Ordinary pregnant and breastfeeding women (with no mitigating factors) fast, except if they are weak and close to being sick.
According to Rav Moshe Sternbuch, common practice on Tish'a Be-Av is also to exempt a me'uberet who usually has difficulty fasting (i.e., when she is not pregnant), as a chola she-ein bah sakana.
Responsa Teshuvot Ve-hanhagot V:169
Indeed, halachic authorities have customarily ruled that only a pregnant woman for whom fasting is generally difficult even when she is not pregnant is exempt, but if fasting is generally easy for her, we instruct her to fast, and only if she feels a unique weakness should she discontinue it and eat immediately, and so is my practice to rule.
Some halachic authorities call for additional leniency on Tish’a Be-Av out of concern for the fetus. Rav Shlomo Zalman Auerbach reportedly exempted pregnant women from fasting on Tish'a Be-Av due to the heat of the day, on a case by case basis.
Here, too, Rav Yisrael Ya'akov Fischer considers all pregnant women exempt from fasting on Tish’a Be-Av, as a matter of sakana:
Responsa Even Yisrael IX:62:10
A pregnant woman is prohibited from fasting on Tish’a Be-Av. And there is no law of shi’urim here, for our sages did not decree [a fast] in the case of danger…
Again, Rav Nahum Rabinovitch rules similarly, and again these blanket exemptions have been contentious.
Women in high-risk pregnancies are often advised not to fast. Healthy pregnant women with no known complications are generally advised to fast. Many halachic authorities instruct me'ubarot to break the fast at any sign of distress or with a particularly strong urge to eat. On Tish'a Be-Av, a me’uberet who feels weak or has a history of difficulty fasting is widely considered exempt. Some halachic authorities have suggested broader exemptions for pregnant women, especially on Tish'a Be-Av.
A me'uberet with any health concern should consult her physician and halachic authority prior to a fast, ideally receiving clear parameters for how to fast safely and when to break the fast. If the decision is reached that she should attempt the fast, then she needs to be very aware of how she is feeling so that she not fast beyond the point of health for her and her fetus.
Yom Kippur and Tish'a Be-Av
From the point at which contractions begin for childbirth and during the first three days postpartum (i.e. for 72 hours from childbirth or pregnancy loss) a yoledet's condition is considered critical. Therefore, she has the status of a chola she-yesh bah sakana, so that we violate Shabbat for her and require her to eat on Yom Kippur or Tish'a Be-Av. We can also violate Shabbat to meet her needs at her request for the first week postpartum:
Mishna Shabbat 18:3
We deliver a woman on Shabbat, and call a midwife for her from place to place, and violate Shabbat for her.
The Nehardean said: A woman who gives birth…[within] three [days], whether she said “I need” or whether she said “I don’t need” – we violate Shabbat for her. [Within] seven [days], if she said “I need,” we violate Shabbat for her; if she said “I don’t need,” we do not violate Shabbat for her…
By the same token, a yoledet within seven days (168 hours from childbirth or pregnancy loss) need not fast as long as she or her physician deem sustenance necessary for her health.
Shulchan Aruch OC 617:4
A yoledet within three days does not afflict herself at all. From three until seven, if she said “I need,” we give her food. From here on, she is like every person.
In practice, a postpartum woman or woman following pregnancy loss generally does not fast on Yom Kippur or Tish'a Be-Av before a full week has passed. Following a Cesarean section, a woman is not technically considered a yoledet, but she is a chola she-yeish ba sakana. She does not fast for the first eight to ten days, depending on her condition.
After the first week postpartum, a woman’s status as a yoledet no longer automatically exempts her from fasting on Yom Kippur. However, she will often be a meineket (discussed below), and may still have the status of a chola. The halacha will depend on her individual circumstances.
Further Leniency on Tish’a Be-Av
Following Ramban, Shulchan Aruch rules that a yoledet within thirty days of childbirth does not fast on Tish’a Be-Av, because it is rabbinic, and our sages did not decree a fast in such cases. Rema agrees that there is room for leniency. He notes, though, that there is a custom for a yoledet (after seven days) to fast on Tish'a Be-Av unless she feels severe discomfort and may be in danger.
Shulchan Aruch OC 554:6
A woman who has given birth within the past 30 days and a sick person who needs to eat, do not need to be assessed by a professional, rather we immediately give them food, as the rabbis did not include the sick in their decree. Rema: Nevertheless, they customarily fast as long as they are not in great distress that may be dangerous, and one who is lenient has not lost out.
Aruch Ha-Shulchan, though, states that women of his era are not as strong or healthy as in the time of Rema. Therefore, a yoledet has the status of a chola and is not allowed to fast on Tish’a Be-Av for the first 30 days post-partum.
Aruch Ha-shulchan 554:8
Maybe this was in their days when the generations were healthy and strong, but now Heaven forbid that a yoledet fast on Tish’a Be-Av within 30 days, because she is still weak and she is really like a chola, and so they should not be allowed to fast on Tish’a Be-Av.
When a yoledet within thirty days of childbirth does not fast on Tish'a Be-Av, she still may be encouraged to fast for a brief amount of time, unless it is difficult for her.
A yoledet doesn't fast during the first week (168 hours) postpartum, and is exempt from fasting on Tish'a Be-Av for thirty days following childbirth.
Yom Kippur and Tish'a Be-Av
The laws of a choleh can be relevant to a nursing baby, and thus to a breastfeeding woman. The Talmud considers a baby to be in mortal danger when mother's milk is unavailable:
Rav Huna the son of Rav Yehoshua said: A typical baby is endangered regarding milk.
Therefore, Chatam Sofer rules that a healthy meineket may eat even on Yom Kippur if her child is fully dependent on her milk and would be in danger if she were to fast.
Responsa Chatam Sofer VI Likutim 23
In a responsa of Devar Shmuel 107 he clearly exempted a healthy breastfeeding woman whose child was in danger regarding her milk, and if she fasted she would grow weak and she wouldn’t have [milk] to nurse, and the child would be in danger – he allowed her not to fast even though she herself was healthy in order to save the child from safek piku’ach nefesh. And he did not bring a proof, and this is simple, for a healthy person may violate Shabbat for a sickness that is safek piku’ach nefesh, even though he himself is healthy; here too a healthy person may eat on Yom Kippur to save the child from safek piku’ach nefesh.
Halachic consensus follows this ruling, though there is some disagreement as to whether it should apply when infant formula is available. Rav Shlomo Zalman Auerbach, for one, views the availability of formula as irrelevant to the discussion.
When the fast actually affects a meineket's milk supply, he goes so far as to allow for her to drink in small amounts (shi'urim, discussed below) on Yom Kippur in the first months after childbirth, even when the baby is healthy:
Halichot Shelomo, Mo’adim Tishrei-Adar 6:2
A nursing woman, if there is concern that her milk will be diminished by the fast or she feels herself that it is lacking, should drink less than a shi’ur at a time, and we do not take into account the possibility of feeding the baby milk substitutes. Note 5: It is proper for her to drink a lot on Erev Yom Kippur, so that she won’t need to do this. Note 11: If many months have already passed from the birth, sometimes one should not be so lenient, and a halachic question should be asked…
Still, Rav Auerbach notes that it is best for a meineket to drink extra in advance of the fast, which can head off disruptions to supply to start with. (Pumping in advance can be helpful as well to have extra milk on hand).
Further Leniency on Tish’a Be-Av
On Tish’a Be-Av, if a meineket herself is sick on the level of a chola she-ein bah sakana, then she should not fast, as is the general rule. In our discussion of a me'uberet, we saw Aruch Ha-shulchan's ruling to exempt a me'uberet or meineket who feels weak or ill from fasting on Tish’a Be-Av.
What if the meineket is healthy? As above regarding Yom Kippur, some halachic authorities maintain that if the baby depends on her milk and she feels her supply drop, she may break her fast.
Additionally, if the baby is dependent on mother's milk and is in distress, regardless of whether the meineket feels a drop in milk supply, then the baby has the halachic status of a choleh she-ein bo sakana, which provides grounds for the meineket not to fast on Tish’a Be-Av.
Maharsham Da’at Torah 550:1 s.v. she-mitzta'arot harbeh
And it seems clear that even if the meineket is not in distress, but her baby is distressed, because he does not have milk to nurse…perhaps even on Tish’a Be-Av she should not fast, for a typical baby is considered a choleh she-ein bo sakana.
Controversially, Rav Nahum Rabinovitch extends this argument to exempt all nursing women from fasting on Tish’a Be-Av:
Responsa Si’ach Nachum 36
… The poskim have already written that the later generations are weaker than the earlier generations; therefore, it is possible that the later ones do not have the strength to tolerate the practice of the earlier ones… It is proven from several sources that pregnant and nursing women have at least the halachic status of a choleh she-ein bo sakana…because of the distress of the baby, a meineket should not fast on Tish’a Be-Av.
In a more narrow and more widely accepted ruling, Rav Sternbuch argues that a meineket should generally fast on Tish’a Be-Av. But if it’s possible that her milk will dry out and this may endanger the child, then she should not.
Responsa Teshuvot Ve-hanhagot IV 130
If there is serious concern that a breastfeeding woman’s milk will dry out if she fasts on Tish’a Be-Av, and the baby will not want to accept an alternative, and this may weaken or endanger the baby, she should be permitted to eat on Tish’a Be-Av, for we permit a sick person [to eat] without professional assessment. And one does not have permission to be stringent in this case because (a stringency) is to the detriment of the child. Even though the established halacha is that pregnant and breastfeeding women fast the full day, a judge can only rely upon what his eyes see and if there is a chance of danger she is allowed to eat… and here when there is even a niggling chance of danger to the child if the milk stops she should not be stringent and fast, because this is a leniency regarding the child, and she does not have permission [to be lenient with the health of the baby].
At the same time, Rav Sternbuch suggests that a woman whose child will take a milk substitute without endangering its health should fast.
Ideally, a meineket should fast. When a meineket's fasting poses a real danger to the infant, she should not fast. Even on Yom Kippur, if the baby depends on its mother's milk and the milk supply is affected, she may break her fast with shi’urim. On Tish'a Be-Av, it is enough for there to be a strong possibility of her milk drying out and thus affecting the baby for the meineket not to fast. Also, if a meineket feels weak and liable to become sick on Tish'a Be-Av, then she should eat.
In both cases, she should take steps, such as extra drinking in the days before the fast, extra pumping to have more milk on hand, and further resting on the fast itself, in order to prevent dehydration or supply issues.
Some halachic authorities have suggested broader exemptions for breastfeeding women (though less so than for a me'uberet), especially on Tish'a Be-Av.
Special concerns about breastfeeding – such as a history of supply problems, a baby with a complicated medical situation, an infant under six weeks old, or even anxiety about fasting – are relevant on both Yom Kippur and Tish’a Be-Av. A woman should seek medical and halachic guidance in advance in order to determine the best course of action.
Is it reasonable to expect pregnant or nursing women to fast?
The 'Yom Kippur effect' of women in late stages of pregnancy being raced to the hospital on Yom Kippur can be frightening. This story from Mishpacha Magazine brings it to life:
C.B. Gavant, "Born on Yom Kippur," Mishpacha, October 5, 2011.
Late on Yom Kippur afternoon Batsheva Freedman [a psuedonym] began to feel mild sporadic contractions….she sent one of her children to shul to ask her husband if she should break her fast. “The next thing I knew my husband burst in the door together with two Hatzolah guys” Batsheva relates. “‘Mrs. Freedman we’re taking you to the hospital immediately ’ ” they said.“ ‘But I’m not having strong contractions! All I wanted to know was whether I should break my fast’ I replied…. When the non-Jewish staff first saw her kittel- and sneaker-clad guardian angels entering the hospital someone commented “Weren’t you guys just here?” “Clear the beds” the men shouted back. “We’ll be coming in all night.”
The most striking aspects of this account are how quickly Batsheva's husband moves to safeguard her health, how focused "Batsheva" remains on the question of whether she should fast amid the turmoil, and how commonplace the Hatzolah team finds her situation.
At the same time, the scientific evidence on the effects of a twenty-five hour fast on nursing or pregnancy remains inconclusive, so that it does not support widespread alarm.
The preoccupation with fasting or not remains prevalent. At the same time, over the last several years we also seem to have witnessed a sea change in women's attitudes toward fasting. Increasing numbers of women have been questioning the need to fast at these vulnerable times of pregnancy and nursing.
Less than 200 years ago, Aruch Hashulchan writes that many women of his time would insist that they were well enough to fast, even right after childbirth.
Aruch Ha-shulchan 617:4
In our time it is known that they themselves will always say that they don't need [food], and it is not possible to rely on this. Therefore, if there is a physician— they should ask the physician. And if not—the expert women should say. If there is a doubt— we give her less than a shi’ur to eat at a time, for we are lenient in cases of possibly saving a life.
It is hard to imagine this happening in a widespread fashion now when women are more concerned about the medical effects of a fast. Instead, nowadays, celebrities like Mayim Bialik have taken to the internet in order to defend the idea of fasting when pregnant or nursing to the questioning public:
Mayim Bialik "Why I Fast on Yom Kippur"
Many people don’t like the concept of fasting, and many people don’t see any religious or spiritual value in fasting. I happen to be a person who likes the concept, and who sees and reaps a tremendous amount of religious and spiritual value from fasting. I also have fasted throughout two pregnancies and through nursing babies and toddlers on demand all day and all night. Am I better than you for fasting while nursing and pregnant? No. Do I work hard to accomplish this? Yes…My personal experience both as a nursing mom and a Certified Lactation Educator Counselor is that during the first three months of nursing, when milk supply is being established, you want to be very careful about supply, and babies will often want to nurse a lot the day AFTER a fast to pull up milk supply that may have dropped from a day of no water and no food. Fasting is so important to me that I put in my best effort to keep it going: I step up my fluids the day before I fast, and I take it super easy…
Why is this the case? Why have attitudes toward pregnant and nursing women fasting undergone such a shift?
Perhaps, as a community, we have lost sight of the significance of fasting. This is regrettable and we should work to change that. (Deracheha's piece on the topic may help.)
And perhaps, as regrettably, there have been far too many women over the years who have taken risks in the name of fasting without knowing that Halacha does not call for them.
It is critically important for a woman to investigate whether it is medically safe for her to fast and how Halacha relates to that. She should work with a physician and halachic authority to ensure that she protects her body and her offspring and honors her commitment to Halacha.
On Yom Kippur
Exemptions from fasting on Yom Kippur often permit eating “less than a shi’ur” at a time. What does that mean? To understand the concept of shi’urim, we first need to revisit the Torah's injunction to afflict ourselves on Yom Kippur.
Eating or drinking on Yom Kippur violates the mitzva of afflicting ourselves and incurs the grave punishment of karet, spiritual excision from the Jewish people.
Vayikra 23: 28
For every soul that is not afflicted on this very day shall be cut off from its nation.
Shulchan Aruch OC 611:1
Liability for karet is only for performing labor and eating and drinking.
The Mishna quantifies the point at which a person incurs the full liability of karet for violating the fast: by eating an amount of food equivalent to the volume of a large date, or by drinking a cheek's full of drink.
Mishna Yoma 8:2
On Yom Kippur, it is prohibited to eat or drink….One who eats the volume of a large date including its pit, and one who drinks a cheek’s full, is liable. All foods combine towards the volume of a date, and all liquids combine towards a cheek’s full. Eating and drinking do not combine [with each other].
The Talmud explains that consuming this amount of food or drink violates the obligation of affliction because it gives one the opposite experience, a sense of feeling settled:
The large date that they said – is less than the volume of an egg. With the volume of an egg, one is satiated. With the volume of a large date, one’s mind is settled.
Our sages stipulate that to violate the obligation of affliction, this amount of food or drink must be consumed within the amount of time that it takes to eat a half a loaf of bread, kedei achilat peras. This is usually understood as nine minutes, but could potentially be as few as two (an opinion relied upon in very pressing situations). The Tosefta explains that smaller amounts of food or drink consumed at longer intervals do not combine to the measurement (shi’ur) for which one is liable:
Tosefta Keritot 2:2
If he ate and then ate again – if from the beginning of the first eating until the end of the last eating is kedei achilat pras, they combine, and if not, they do not combine.
What if someone eats less than a shi’ur? The Talmud asks why the first clause in the mishna above uses the relatively tame term “prohibited” (assur) with respect to eating on Yom Kippur, instead of stating that one is “liable” (chayyav) for karet. It suggests that this language teaches that any eating and drinking is prohibited, even if one does not consume the full measure required to incur the punishment of karet:
[Why does the mishna say] "prohibited"? The punishment is karet! Rabbi Ila, and some say Rabbi Yirmiya, said this was only necessary [to teach about] a partial measure. As it was stated of a partial measure: Rabbi Yochanan says it is prohibited by the Torah; Reish Lakish says it is permitted by the Torah…Reish Lakish concedes that it is prohibited by the rabbis.
Halachic consenus follows Rabbi Yochanan, who typically prevails in disputes with Resh Lakish, and considers eating a partial measure on Yom Kippur as a Torah violation. There seems to be an implicit prohibition of eating or drinking even the smallest quantities on Yom Kippur, perhaps because even a small amount detracts from affliction. Rambam and Shulchan Aruch both rule in this vein:
Rambam, Laws of Shevitat Ha-asor 2:3
If he ate or drank less than this shi’ur, he is not liable for karet even though a partial shi’ur is prohibited on a Torah level, one is liable for karet only with a [full] shi’ur. One who eats or drinks a partial shi’ur receives lashes of rebelliousness.
Shulchan Aruch OC 612:5
A shi’ur is only necessary to incur [the punishment of] karet or [the obligation to bring] a sin-offering, but any amount is prohibited.
When to Eat or Drink in Shi’urim
Based on these opinions, we would think that consuming any amount of food or drink on Yom Kippur is restricted to cases of danger or possible danger to life, when piku’ach nefesh pushes aside Torah law. The Semag even writes that Reish Lakish, who considers the violation rabbinic, permits eating an amount less than a shi’ur only in cases of mortal danger.
And yet – in cases of real danger, why would measures matter at all? Isn’t the restriction to less than a shi’ur superfluous where a life is at stake, when one should be able to eat as much as necessary? According to some interpretations, the following Talmudic passage addresses exactly this point:
It is taught: They permitted a pregnant woman to eat less than a shi’ur because of danger. Because of danger – she should even eat a lot! Rav Pappa said, it is taught thus: It was permitted to a pregnant woman less than a shi’ur, even a lot, because of danger.
Ramban interprets this passage to mean that even someone in danger who is allowed to eat on Yom Kippur (or to violate other prohibitions of eating) should still take care to break up the eating into partial shi’urim, when possible, so as not to perform an act that would otherwise be considered punishable by karet:
Ramban, Torat Ha-adam, Sha'ar Ha-michush, The Matter of Danger
It means that even if she requires a full shi’ur, we give her food in smaller increments so that it does not combine …. And it seems that we do this even for a sick person to lighten a prohibition entailing karet and lashes to a simple prohibition.
On this reading, piku'ach nefesh doesn’t entirely eliminate the restrictions of Yom Kippur. Therefore, mitigating the theoretical punishment by eating small amounts at a time makes a significant difference. Note that Ramban here equates the situation of a pregnant woman who is certain she must eat with that of a choleh she-yesh bo sakana.
Perhaps inspired by this case, Sefer Ha-chinuch writes that is it permissible for even a choleh she-ein bo sakana who is especially weak to eat in this way.
In practice, Shulchan Aruch rules according to Ramban’s opinion that a me’uberet or choleh she-yesh bo sakana should eat and drink quantities less than a shi’ur at intervals longer than kedei achilat peras (known as “shi’urim”), as long as this is sufficient for them. If the doctor, pregnant woman, or choleh say that eating in shi’urim is not enough, or are not sure it will be sufficient, then they may eat without restriction.
Shulchan Aruch OC 618:7-8
When we give food to pregnant women or to a choleh, we give them food a little at a time so that it does not combine to a shi’ur. Therefore, we feed them about two-thirds of [the volume of] an average egg, and they wait for the amount of time it takes to eat [the volume of] four eggs. With drink, we check based on the choleh himself, how much [liquid he can hold in his mouth] so he pushes it to one side and it looks like a cheek’s full. We give him less than that shi’ur to drink, and they wait between drinks the amount of time it takes to eat [the volume of] four eggs, and they at least wait between drinks the amount of time it takes to drink a revi’it. If it was assessed that these shi’urim are not enough for him, or if the choleh says so, or if they are uncertain, we give him to eat and drink as much as he needs.
We saw above that the shi’ur for eating is the volume of a large date. In practice, the volume of an egg (ke-beitza) is a much more common shi’ur for various halachot of eating, and thus more familiar. Therefore, Shulchan Aruch specifies that one should eat about two-thirds of the volume of an egg at one time. This is safely within the volume of a large date, which is only slightly smaller than an egg. Halachic consensus today is that the shi’ur for eating is 30cc.
The shi’ur for drinking, a cheek’s full, depends on the particular person. Ideally, it is measured before Yom Kippur. A person can fill her mouth with water, and spit out the water into a measuring cup. One cheek’s full is about half that quantity.
Since food and drink do not combine to make a shi’ur, this translates to less than a shi’ur of food and less than a shi’ur of drink every nine minutes—and these can be staggered. The nine-minute measure can also be reduced, as necessary, in accordance with more lenient opinions.
Rav Zalman Melamed notes that eating in shi’urim can be problematic in its own right, since eating or drinking a small amount every few minutes in order to consume enough to stay out of danger may preclude the sick person from getting the rest they need. Therefore, he rules that when a sick person also needs their rest, such as a yoledet who is exhausted, they should eat and drink normally so that they can sleep and recover.
Peninei Halacha Yamim Nora’im, The Laws of the Fast 8:5
However, if there is any concern that eating and drinking this way will cause at-risk patients to neglect the recovery of their strength, they must eat and drink normally. For example, if a postpartum woman is exhausted, it is better that she drink normally so that she can have uninterrupted sleep than that she stay awake to drink small quantities intermittently.
Shi’urim on Tish’a Be-Av
Do shi'urim apply on Tish'a Be-Av?
Many halachic authorities, including Aruch Ha-shulchan, maintain that there is no constraint of shi'urim on Tish'a Be-Av when someone does not fast, regardless of that person's choleh status.
Aruch Ha-shulchan OC 554:7
Less than a shi’ur is not relevant on Tish’a Be-Av, which is rabbinic
Aruch Ha-shulchan views the concept of shi'urim as relevant only in Torah-level contexts. Similarly, Rabbi Dr. Avraham S. Avraham, in his compendium of medical Halacha, writes that Shulchan Aruch strongly implies that shi’urim do not apply on Tish’a Be-Av to someone who is sick, for whom our sages made no decree to fast.
At the same time, he notes that Rav Shlomo Zalman Auerbach ruled that someone who is currently healthy, but is not fasting out of concern for becoming sick, or for potential threat to a fetus, should eat measuring out shi'urim:
Nishmat Avraham OC 554
However it seems from a plain reading of Maran (Rav Yosef Karo) that one is allowed to eat what he eats normally every day, and not only what is necessary. Furthermore, since he writes that "our sages did not decree in a case of illness," it is clear that for a choleh there is no fast day….Update: Rav Shlomo Zalman Auerbach told me that we hold that a choleh does not need to eat shi’urim, but a healthy person who may get sick, such as in a case when there is a plague in the city, or a pregnant woman who is weak and is worried she may get sick, should eat shi’urim. Up to here are his words. A choleh who only requires drink and does not require food, such as a person suffering from a kidney stone, my teacher Rav Yehoshua Neuwirth told me that he should drink and not eat.
Rav Shlomo Zalman Auerbach's ruling could apply to a nursing woman who does not fast on Tisha Be-Av due to concern for the health of her infant.
When the 9th of Av falls on Shabbat, the fast is pushed off, nidcheh, beginning Saturday evening, and ending Sunday night. In this case, a berit mila may be performed in the early afternoon, and the ba’alei berit (the father, mohel, and sandak according to Beit Yosef and Rema) may break their fast afterward.
Shulchan Aruch OC 559:9
On a Tish’a Be-Av that falls on Shabbat and is pushed off to Sunday – a ba’al berit prays mincha in the early afternoon (mincha gedola), washes, and does not finish his fast, because it is personal yom tov (festival) for him.
This halacha seems to indicate that the laws of Tish’a Be-Av nidcheh are less stringent than those of a regular Tish’a Be-Av, on which no one would be allowed to break their fast in honor of a berit mila. Rav Ya'akov Reischer, who it appears would usually require a yoledet from seven to thirty days or a me’uberet to fast on Tish’a Be-Av unless they experience distress, applies this idea to allow for breaking a fast more readily on Tish’a Be-Av nidcheh, at the first sign of discomfort.
Responsa Shevut Yaakov III 37
Since Tish’a Be-Av was nidcheh to Sunday one does not need to complete the fast, even if he is a bit sick, and this is how I customarily rule for yoldot within 30 days and pregnant women who are a bit uncomfortable – for they [the sages] were even lenient regarding the honor of mila.
Although contemporary custom does not follow the Shulchan Aruch’s ruling concerning a berit, instead scheduling the berit in late afternoon and the celebratory meal after dark, Rav Reischer's ruling remains influential.
Rav Ovadya Yosef concurs, and adds that breastfeeding women also need not fast on Tish’a Be-Av nidcheh. Nevertheless, Rav Ovadya deems it proper to fast at least until midday when possible. A person eating in this case must recite havdala and drink from the cup (or give it to a child) just prior to eating.
Responsa Yechaveh Da’at III 40
And it is found that a delayed Tish’a Be-Av is more lenient than the other taaniyot tzibbur that fall in their proper time, for ba’alei berit do not fast on a delayed Tish’a Be-Av, but they are obligated to fast on the other fasts that fall in the proper time. And since pregnant and breastfeeding women are exempt from fasting the three fasts, even if they fall in the proper time, all the more so they are exempt from fasting on a delayed Tish’a Be-Av. According to Chemed Moshe (562:1), who rules that ba’alei berit may eat in the morning on delayed Tish’a Be-Av, pregnant and breastfeeding women are also allowed to eat from the morning. But it is proper that they join in the mourning and fast of the community and fast until chatzot (midday) and afterward they eat and drink….They must recite havdala over a cup before they eat, for it is prohibited to eat anything until one recites havdala over a cup…
What should I do to connect to the fast if I am exempt from fasting?
Often, a woman exempt from fasting on Tish'a Be-Av or Yom Kippur can fast at least overnight without harm to herself or offspring, in order to participate in part of the fast. Despite such efforts, not fasting can be as challenging as fasting.
When eating for health purposes on Tish'a Be-Av or on Yom Kippur, at any point over the course of the day, it can be helpful to have in mind beforehand that one is eating to fulfill the mitzva of "ve-chay ba-hem," living by the mitzvot, and eating thoughtfully in a way that places an emphasis on nourishment and health.
The following prayer, popularized by the work Torat Ha-yoledet, can help those who must eat or drink to focus in on how that, too, is an act of serving God:
Prayer for an Ill Person who must Eat on Yom Kippur
Here I am ready and prepared to fulfill the mitzva of eating and drinking on Yom Kippur, as You wrote in Your Torah "keep my ordinances and my laws that a person should do and live by them, I am the Lord" (Vayikra 18:5). By merit of fulfilling this mitzva, may You seal me and all the ill people of Your people Israel for complete healing and may I merit next Yom Kippur to fulfil again "And you should afflict your souls". So may it be Your will, Amen.
Since fasting is not the only special aspect of a fast day, Rav Sternbuch writes that a pregnant woman who is not fasting should try to be a part of the community as much as possible. On Tish’a Be-Av this can mean limiting the type of foods she eats to one cooked dish at a time, as is done at the se’uda mafseket before Tish’a Be-Av:
Responsa Teshuvot Ve-hanhagot V 169
Nevertheless, even if we permit [eating] during the daytime to a pregnant woman, she is still obligated to participate with the community, and even when she eats fruits and drinks without considerations of shi’urim, it is no less significant than the eve of Tish'a Be-Av and [as is the rule then for mourning] she should not eat two cooked items…
Although fasting should be prioritized over attending synagogue on fast days, someone who does not fast may make a priority of attending services or of setting aside time to pray, to recite liturgical readings, and to reflect and perform teshuva over the course of the day.
Deracheha's Editor-At-Large Sarah Davis Rudolph talks about her experiences in this situation, and what she has learned from them:
Sarah Davis Rudolph, “How eating on Yom Kippur was, and wasn’t, everything I’d ever dreamed it could be”
Generally speaking, I not only require food, but I enjoy it. This Yom Kippur, though, I wasn’t eating to enjoy: it was purely for nutrition…I wasn’t eating anything for me; it was all about her. Every ten minutes, I made a decision – does she need another ounce of almond milk? An ounce of trail mix? Water this time?...Every bite had purpose – and to my mind, purposefulness is the very definition of holiness. So, eating on Yom Kippur was an exciting opportunity to live halacha a little differently, and to focus on physicality in a purposeful, holy way. But it was also sad….There is a great deal of power in personal prayer, but for me, the power of Neilah in particular comes from community. And I realized this year more than ever that it comes from having been through the day together, fasting however badly or well one fasts, crying out together and mumbling quietly to G-d together. Yom Kippur can be an overwhelming experience, and it is at its most powerful as a shared experience. I had hoped that eating on Yom Kippur would give me the strength to focus on my prayers better. But instead, I found that there is actually something positive about fasting.
When not able to fast, we can gain new appreciation of what fasting means while honoring the halachic imperative to preserve health. Finding a balance between the two, we can seek out moments of connection, holiness, and purpose.
- Rav Prof. Dov Frimer, Machon Schlesinger, Me’ubarot U’meinikot Be-tzom Tish’a Be-Av Ve-Yom Ha-kippurim – Hora’ot Hilchatiyot shel Poskei Doreinu. Available here.
- Rav Menachem Borstein and Rav Gavriel Goldman, Tzom Yom Ha-kippurim Le-nashim Me’ubarot. Available here.
- Rav David Brofsky, "Can Pregnant And Nursing Women Eat On Yom Kippur?" 9.13.18, The Jewish Press
- Rav Nahum Eliezer Rabinovitch, Ubarot U-meinikot Be-Ta’anit, Responsa Si’ach Nachum 36. Available here.
 Shulchan Aruch OC 617:1
Pregnant and nursing women fast the full day on Yom Kippur.
Shulchan Aruch OC 617:1
Pregnant and nursing women fast on Tish’a Be-Av, as they fast the full day on Yom Kippur
 Shulchan Aruch OC 328:17
An ill person who needs to lie down because of his illness and is not in danger (Rema: or who has a minor illness and is distressed, and his whole body is affected, in which case even if he is walking, he is similar to someone who needs to lie down), we tell a non-Jew to give him medical assistance, but we do not violate Shabbat for him with a Torah prohibition, even if a limb is in danger. For a Jew to actively violate Shabbat for him with a rabbinic prohibition, some permit even without danger to limb; and some say that if there is danger to limb we do, and if there is no danger to limb we don’t. Some say that if there is no danger to limb we do it in an unusual manner, and if there is danger to limb we do it in the usual manner; and some say that even if there is danger to limb, we do not do anything that is adjacent to a Torah-prohibited labor, and we do things that are not adjacent to prohibited labor even if there is no danger to limb; and the third approach seems correct.
 Shulchan Aruch OC 554:6
A sick person who needs to eat, does not need to be assessed by a professional. Rather they are immediately given food, as the rabbis did not include the sick in their decree.
 Shulchan Aruch OC 618
1) A sick person who needs to eat, if there is an expert physician present, even a non-Jew, who says that if he is not given food the illness may become more severe and endanger him, we give him food at his direction and it goes without saying, lest he die. Even if the sick person says that he does not need, we listen to the physician. If the sick person says, “I need” – even if 100 physicians say that he does not need, we listen to the sick person.5) If the sick person says he does not need, and the physician is uncertain, we give him food. But if the physician says he does not need and the sick person says, “I don’t know,” we do not give him food.
 Darkei Moshe Ha-katzar OC 328:6
The Issur Ve-heter Ha-aroch wrote (59:7), The fact that ordinary people are somewhat expert refers to ordinary Jews but not to ordinary non-Jews.
Mishna Berura 618:1
See above 328:10, where the author [Shulchan Aruch] cites the opinion that some say we do not require an expert, but any person is presumed to be slightly expert regarding a doubt in matters of life and death (that is, where he at least says he understands this illness), and Rema concludes there that this opinion specifically refers to a Jewish doctor, but a non-Jew is trustworthy only if he is an expert, and here the law is thus.
 Regarding Tish’a Be-Av, Rav Moshe Sternbuch quotes the following tradition in the name of Rav Chayyim Brisker, and supports it with an anecdote about Rav Chayyim's son, the Brisker Rav:
Responsa Teshuvot Ve-hanhagot IV:130
Rav Chaim of Brisk zt”l explained that in a case where [the rabbis] did not decree a fast, even if one fasts he has not fulfilled the mitzva of fasting on Tish'a Be-Av, because they did not decree [a fast] for him. (And I remember walking once with the Gaon of Brisk Rav Yitzchak Ze’ev Soloveitchik (Ha-Gri”z) zt”l and he saw a Jew who passed by us who was sick with diabetes, and Ha-Gri”z chased after him and said to him – I am worried you will fast on Tish’a Be-Av. You should know that you are sick and should not fast.)
 Dr. Eli Yosef Shussheim, “Tzom Yom Kippur al pi Ha-halacha Ve-harefuah,” in Mo'adei Kodesh, edited by Binyamin Adler (Jerusalem, 1990), 307-311.
 Nishmat Avraham OC 617
In Vitro Fertilization (IVF). The danger of miscarriage for a woman who conceived through IVF treatment is higher in the first weeks of pregnancy, whereas afterwards there is no difference between her and a woman who conceived in the usual manner….For a woman who has serious difficulties with fertility and a sensitive pregnancy (according to the factors above), we don’t know if refraining from drink and dehydration during the fast could be an additional factor in causing miscarriage, during the first weeks when there is a high risk of miscarriage. Rav Shelomo Zalman Auerbach said to me that, since there is a doubt in this matter, such a pregnant woman must drink in shi’urim during the first weeks of her pregnancy (and of course not to go to synagogue during the day).
 For a recent ruling by Rav Yehuda Henkin on fertility treatments and fasting, see here:
 Rema adds that a woman does not need to ask for the food. It is sufficient that there be a discernable sign of physical distress, such as her face changing. Magen Avraham notes that the converse is also true, even if the woman’s face does not change, but she states she needs to eat, she is given food:
Magen Avraham 617:1
Even if she does not say. This implies that [we also give her food] if she says she needs, even if her face does not change.
 Rabbi Professor Nahum Eliezer Rabinovitch, “Ubarot U-menikot Be-ta’anit,” Techumin 17, 5757
The fact that Behag formulates his law in general terms “that we know…that her fetus will be uprooted,” and brings a proof for this from the law of a woman who smelled – this proves that perhaps not only with a woman who smelled is there such a risk, and this is not a specific law for a woman who smelled, but of course the matter depends on whether we have any knowledge that this is similar. In recent times, the doctors have discovered that from the fifth month on, there is a recognized chance that the fast could cause uterine contractions – that is, that the fetus could be uprooted from its place and there would be a miscarriage, Heaven forbid, or at best a premature birth with all the risks entailed in that. The Bach (617) compared: “A pregnant woman who smelled [food], even if her face did not change, we give her food, for even though she herself is not currently in danger, since her face did not change, nevertheless, the offspring is in danger, for if she does not eat, her offspring will be uprooted and die. And then she will also be in danger, for every woman who miscarries has a presumption of danger. And thus it seems from the language of Rosh and Ran … and it seems from the Rambam that he takes the same approach as Rosh and Ran and our Rabbi [Tur]."… In a place where there is concern that the fetus will be uprooted, and even where the woman does not feel weak, this is considered piku’ach nefesh and the pregnant woman is required to eat even on Yom Kippur, and, it goes without saying, on Tish’a Be-Av. Since it has been proven that in many cases the fast may cause uterine contractions from the fifth month of pregnancy on, one must be concerned about this. Of course, on Yom Kippur she should eat or drink less than a shi’ur, and with an interval of kedei shi’ur achilat peras.
 Rav Shlomo Zalman Auerbach also opposed blanket rulings to exempt pregnant women from fasting on Yom Kippur, and reportedly took a similar line of argument:
Nishmat Avraham 617:1
Our master and teacher Rav Shelomo Zalman Auerbach saw these words and agreed with them, and added in writing: “But if she feels very bad, it is desirable that she drink less than a shi’ur at a time.” In Halichot Shelomo, it is written in his name: “Every healthy woman with a healthy pregnancy, who also has not miscarried at previous times, there is no reason in the opinion of the doctors that the fast could cause damage to her or to her fetus except exceedingly rarely, and therefore something that rarely, in special circumstances, may cause harm to the woman or her fetus, is not in the category of danger, and she should fast normally, because since the sages established that a typical me’uberet is obligated to fast – even though in their time when they did not have intravenous liquids and so on – and they were not at all concerned that the fast might cause danger, we cannot permit in general what they explicitly prohibited. And even in the ninth month she should fast normally, because the concern that decreased liquids and blood volume as a result of the fast might endanger her afterwards if she gives birth on Yom Kippur, is, according to the doctors, a very slight concern.” In a footnote there: “It should be noted that even after he was shown an opinion published by doctors on this matter, he did not agree to a general leniency in this, and was very upset with those who wished to be lenient with this with the serious fast of Yom Kippur.”
 Rav Sternbuch explains why fasting in the ninth month is not a trivial matter:
Responsa Teshuvot Ve-hanhagot V:169
… Know that there are poskim who are lenient as I have written, but in the ninth month when it does not matter whether she gives birth since there is no danger, they were not lenient, but with weakness one should take the side that perhaps if she gives birth when she is weak from the fast, she will be in greater danger during the birth, and even if she eats as soon as she feels birth pangs, in any case she will remain weak from the fast and the birth will be very difficult. If so, since her condition is worsened from the fast, she is exempt from fasting, and one should exempt her primarily because, even though there is no danger to the baby born preterm before the end of the ninth month, but it is prohibited to induce and rush the birth, because we maintain that [the baby’s] limbs are complete only when it is naturally about to be born, and until then its limbs are weak (and she is exempt from fasting, because it worsens the condition of the baby), and therefore one who is lenient with weakness has a basis to rely on. (In any case, at the end of the ninth month when the limbs are fully formed, it seems that she needs to fast if it is clear that it will not be harmful.)
Rav Sternbuch offers two grounds for leniency in the ninth month. If the woman feels week, it may be dangerous for her to go into labor while fasting. Furthermore, it is better for the fetus to reach full term.
 Halichot Shelomo, Mo’adei Ha-shana Nissan-Av, 15, Orchot Halacha note 2
This is what our Rabbi would rule for those who ask. But he would usually add afterward that in our times halachic authorities in the Land of Israel would be lenient for pregnant women, that they should not fast because of the difficult climate and weakness of the generations. (And to some inquirers he would say ‘My mother and wife did not fast on Tish’a Be-Av when they were pregnant.) And this is how our Rabbi would act with his own family, every woman whom he knew that she may become weak or something similar if she fasted, he would instruct her in the days before the fast that she should not fast, and he said that even if he was more lenient than what is explicitly stated in the poskim, he was ruling according to the tradition of teachings in the Land of Israel…With all that, he was careful and did not permit saying this in his name as a general permission, rather he investigated for himself every questioner…
 Available here: https://www.ybm.org.il/lesson?lesson=5557&format=H
 Mishna Berura 617:9
A yoledet – And even if she has not yet given birth, just been seized by birth pangs, and it is clarified in 330:3 that she is considered a yoledet for the matter of violating Shabbat for her, and the law is the same, that she is also considered a yoledet for this matter, that she not fast.
 Mishna Berura 617:13
We do not count them by the hour – see above 330, Mishna Berura 10, that several poskim maintain that these days are calculated by the hour, and that in practice one should be lenient, and thus I found in Yeshu’ot Ya’akov that the one who is lenient with doubt concerning matters of life and death, to calculate the seven days by the hour, has not lost out.
Counting by the hour, “me’et le-et” means counting 24-hour days from the moment of birth. Thus, the three days would conclude 72 hours postpartum. A more stringent approach would be to count the day of the birth as day one, followed by two full days. According to the lenient approach, a woman who gave birth at 11:00 a.m. on Monday would finish her three days after 72 hours, at 11:00 a.m. on Thursday. According to the stringent approach, her three days are Monday, Tuesday, and Wednesday, and she finishes her three days at nightfall on Wednesday evening.
Machon Schlesinger, “Sick people on Yom Kippur, General Guidelines for the fast based on the rulings of Rav Shmuel Wosner”
A woman who gave birth by Cesarean section [does not fast] until 8-10 days (according to the situation and the determination of a qualified physician)
 Maharshal rules that the fundamental halacha here is in accordance with what Rema described as custom:
Responsa Maharshal 53
… And in any event she is not considered a yoledet for the entire 30 days, but rather only for the time that she is still weak and is not healed from giving birth. But when she returns to health she should fast, even the other fasts that are written… [and she does not need assessment (to break her fast)] within seven days, but after seven days even if she says “I need (to eat)” she should fast unless she is a bit sick.
According to Maharshal, a woman only has a blanket exemption as a yoledet for seven days postpartum. Afterwards, the exemption only applies if she still feels weak and has not fully recovered from giving birth. In practice, it is unusual for a woman to feel fully recovered from giving birth within thirty days.
 Mishna Berura cautions that a yoledet between days seven and thirty who feels healthy enough to fast but then experiences unusual weakness on the fast day must eat immediately.
Mishna Berura 554:9
If a healthy yoledet fasts and in the middle of the day she feels extra weakness, she should stop and should not fast the rest of the day.
 Mishna Berura 554:14
See Eliyahu Rabba who wrote that even a yoledet who is not fasting should try to fast a few hours. But if even this is difficult for her, she should not fast at all.
 Be’er Heitev 617
A meinika whose child is sick and in danger and is willing to nurse only from her, and if she fasts, it endangers the child, she does not fast even on Yom Kippur, Teshuvat Devar Shemuel 107.
Some opinions also consider changes in feeding that are likely to cause fever or intestinal difficulty to be safek sakana even for otherwise healthy children.
Chazon Ish Shabbat 59:4
In our time, when illnesses that break forth in babies are very common, it seems that wherever there is uncertainty that it might cause him intestinal difficulties, whether constipation or diarrhea, or cause stomach pain, or any fever, this is in the category of safek sakana, for any damage may possibly cause illness, and any illness is safek sakana…
 Rav Mordechai Eliyahu, for one, argues that a drop in milk supply is not sufficient reason to break a Torah level fast, given the availability of formula:
Rav Harari, Mikra’ei Kodesh Le-Yom Ha-kippurim 9, note 57
Rav Mordechai Eliyahu said to me, that a nursing woman where it is known that her milk will stop because of the fast, but it is not known whether her baby is dependent only on her milk, or perhaps would suffice with Materna [a brand of infant formula] or other substitutes, in this case, this nursing woman should not eat, and not even in shi’urim, but we say that the baby will suffice with Materna. Indeed, on Tish’a Be-Av we are lenient with this, but on Yom Kippur we are stringent.
Other authorities, including Rav Shlomo Zalman Auerbach (infra), disagree.
 See also the view of Rav Avigdor Nebenzahl, who maintains that any woman actively breastfeeding whose milk might dry out should drink shi’urim on Yom Kippur:
Rav Harari, Mikra’ei Kodesh Le- Yom Ha-kippurim Chapter 9, n. 57:
In the name of Rav Avigdor Nebenzahl, who told me regarding a meineket: If there is concern that her milk may stop, she must drink shi’urim. And in the Land of Israel on hot days there is obviously a concern that her milk may stop. And the reason is that the gemara says a typical baby is critically dependent on milk, and so if a woman begins immediately at the beginning of the day to drink shi’urim, usually her milk will not stop… and he added that this applies to all babies up to 24 months old if the child still nurses. And I asked him if this even applies to a woman who partially breastfeeds? And he answered that his words also apply to a woman who partially breastfeeds, since the other things, even the replacement “Materna” (formula) do not protect a baby like real mother’s milk. And even if a child breastfeeds only once a day this is the law, because a mother’s milk protects him from diseases,… and Chazon Ish said that any change in [a baby’s] diet is piku’ach nefesh.
 Rav Ovadya Yosef makes this point clear:
Responsa Yechaveh Da’at I:42
All this is with typical pregnant and breastfeeding women, but if there is any type of illness, even if it is not critical, they should not fast, as explained by Ramban in Sefer Torat Ha-adam, that a choleh she-ein bo sakana does not need to be assessed but we give him food immediately, since the rabbinic decree did not include the sick.
 Available here: https://mishpacha.com/born-on-yom-kippur/
 Sukka 28a-b
Yom Kippur is derived from Rav Yehuda in the name of Rav, for Rav Yehuda said in the name of Rav, and it was also taught in the school of Rabbi Yishmael: Scripture says “man or woman” – the verse equates a woman to a man for all the punishments in the Torah.
 Responsa Chatam Sofer VI – Likutim 23
One should wait kedei achilat peras between one drinking and the next, which is at most 9 minutes, and at least 2 minutes.
 The Yerushalmi may be interpreted as supporting this conclusion (although it is possible that Reish Lakish here is referring to a partial measure of prohibited labor, and not of food):
Talmud Yerushalmi Terumot 6:1
Rabbi Shimon ben Lakish said, if he ate [food the volume of] half an olive in one episode, he is exempt … Rabbi Shimon ben Lakish concedes with prohibitions on enjoyment, and Rabbi Shimon ben Lakish concedes with Yom Kippur, and Rabbi Shimon ben Lakish concedes with one who will later complete [the shi’ur].
Penei Moshe ad loc.
Rabbi Shimon ben Lakish concedes with prohibitions on enjoyment – [it is prohibited] by Torah law, that even a partial shi’ur is prohibited. Rabbi Shimon ben Lakish concedes with Yom Kippur – that even a partial shi’ur is prohibited, and similarly he concedes when he will later complete to a full shi’ur, since that was his original intention, even though he has thus far eaten only a partial shi’ur, this falls within the prohibition.
 Semag Keritot 13a
Because of danger – Even according to Reish Lakish, who considered a partial shi’ur permissible according to Torah law, it is still prohibited rabbinically, and they [the rabbis] permitted in a case of danger.
 Notably, not Tosafot ad loc., who read the case more contextually, as related to ritual impurity and teruma.
 Rosh quotes Ramban and then distinguishes between the two cases:
Rosh Yoma 8:13
It seems to me that with a sick person we don’t do this except on the word of a physician. If he says that it is enough to give him a little bit of it at a time, and similarly with a pregnant woman also, if her mind is not settled with this, it is necessary to give her a shi’ur to eat.
A me’uberet in this case does not necessarily require professional medical confirmation that she is in danger when she is certain she should eat. The very lack of yishuv da'at, settled mind, that affliction is meant to create can sometimes pose a danger for her, and we may give her food based on her intuition that she needs to eat. At the same time, we may not give food to a choleh without medical confirmation.
 Sefer Ha-chinuch 313
Therefore, someone who is sick, even though he is not fully in danger, if he is very weak it is proper to give him food and drink little by little in shi’urim as we said, and we leave time between one eating and drinking to the next kedei shi’ur achilat peras…
 See Chatam Sofer, n. 27 (supra).Steinberg, Encyclopedia Refu'it Hilchatit III "Yom Ha-kippurim," 771-5.
 Rav Wosner, for example, rules that a pregnant woman who is even a bit uncomfortable may eat on Tish'a Be-Av nidcheh.
Responsa Shevet Ha-Levi VI 70:4
… And so regarding a yoledet 30 days postpartum, she should in any case be lenient and not fast on Tish’a Be-Av nidcheh, and similarly the Gaon Rabbi Akiva Eiger wrote (OC 559) in the name of Shevut Yaakov that even someone who is a bit sick and a pregnant woman who is a bit uncomfortable are allowed to eat in this case.
On Tish'a Be-Av nidcheh, Magen Avraham extends total exemption from fasting to a yoledet on her eighth day:
Magen Avraham 554:9
A woman who gave birth, the entire 30: Maharshal wrote in a responsum that a woman who gave birth on Shabbat the 2nd of Av is obligated to fast on Tish’a Be-Av nidcheh, because she is exempt specifically within seven days, but after seven, even if she says she needs [to eat], she is obligated unless she is a little bit sick. And this is the language of Darkei Moshe. However, Beit Yosef 559 implies that she should [normally] fast after seven … however, on Tish’a Be-Av nidcheh one should be lenient.
Magen Avraham discusses the case of a woman who gives birth on Shabbat the 2nd Av. Such a woman is within 7 days postpartum on the 9th of Av, and would normally be exempt from fasting according to many opinions we saw above. However, in this case as the fast is pushed off to Sunday, she now 8 days postpartum and, according to most opinions, required to fast unless there are extenuating circumstances. Magen Avraham concludes that since Tish’a Be-Av is nidcheh she should be lenient and refrain from fasting. Mishna Berura (ad loc.) agrees. (Today, many women are lenient for the first 30 days postpartum in any case.)
 Available here: jewishvaluesonline.org/blogArticle.php?id=203