Fasting on Yom Kippur During Pregnancy

pregnant belly with background of clock towerYom Kippur begins this Friday evening, September 17, and continues until Saturday evening. According to the Shulchan Aruch, the Code of Jewish Law, pregnant and nursing women are required to fast both on Yom Kippur (Day of Atonement ) and Tisha B’Av (9 Av, a day of mourning for the destruction of the Temple in Jerusalem).

Also see: Rabbi Elgazi on Breastfeeding, Pregnancy and Fasting on Yom Kippur (2012)

As I wrote in 2007 our local rabbi has ruled, based on Rabbi Nachum Rabinovich’s ruling, that nursing and pregnant women should not fast completely on those days. Instead, they should eat and drink shiurim beginning in the evening. According to Jewish law there is a minimum quantity, or shiur, or measurement that one must eat or drink in order to be breaking the fast. A person who eats less than this quantity within a specific time period is not fasting according to the strictest letter of the law. So in borderline cases this dispensation is often given.

The Nishmat website, which comes out strongly on the side of fasting for nursing and pregnant who have no complications, describes shiurim as follows:

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). [MiI: 40 cc for me.] If eating is necessary, a woman may eat up to 30 cc at a time [MiI: one ounce]. 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. A woman who needs to break her fast should have in mind while eating that she is fulfilling the mitzvah of “vechai bahem”, living for the sake of Torah (and not risking life).

I’ve heard that some women find a complete fast easier than eating or drinking shiurim, but I don’t believe that is a reason to avoid the leniency. The fluid—preferably juice and not water, for the extra calories—or food is clearly beneficial to the fetus or nursing baby, even if the mother senses no difference.

Rabbi Josh Waxman of Parshablog discusses the halachic basis of the ruling of Rabbi Rabinovich. A commenter wrote: “I think the real problem is the baseline assumption – mine is that without clear evidence, shomer psaim hashem kicks in. Every year, whole communities of women fast with no observed ill effect.

This is a common claim, rejected by Rabbi Waxman:

I would have to disagree, though you are of course entitled to your opinion. What do you mean “no observed ill effect?” How could you know this? The only way you could know this is if you spun off another universe in which the women did not fast, and compared on a case by case basis to see that no woman had premature labor in our universe, and that the birth weight and fetal development was are the same. In fact, some portion of women do miscarry or have premature labor. And some infants have problems with development. Are these the result of fasting? I certainly do not know. But you certainly do not know either. However, studies performed on animals as well as on fasting pregnant women can assist in assessing that.

Rabbi Waxman, while not ruling one way or the other, provided links to studies that found concerns with fasting during pregnancy:

Source I: Metabolic Changes in Asian Muslim Women Pregnant Women Observing the Fast in Ramadan


1. Metabolic changes associated with Ramadan fasting were studied in eleven Asian pregnant mothers. This was compared with a group of control mothers undergoing a normal physiological fast.

2. At the end of the Ramadan fast day there was a significant fall in glucose, insulin, lactate and carnitine, and a rise in triglyceride, non-esterified fatty acid and 3-hydroxybutyrate. When compared with the control group, none of the Ramadan mothers had a completely normal set of biochemical values at the end of the fast day.

3. Pregnancy outcome in the two groups was comparable.

4. We are wary of the metabolic departures from normal observed in the Ramadan fasting mothers. If asked we advise mothers to take up the dispensation from fasting during pregnancy which is allowed.

Source II: Journal of Nutrition: Role of Psychosocial and Nutritional Stress on Poor Pregnancy Outcome

Epidemiological evidence suggests that maternal psychosocial stress, strenuous physical activity and fasting are independent risk factors for preterm birth and low birth weight. Data from clinical studies consistently demonstrate that women in preterm labor have significantly elevated levels of corticotropin-releasing hormone compared with age-matched control subjects. Because production of corticotropin-releasing hormone appears to be stress sensitive, this neuropeptide may play a critical role in the physiological mediation among stressful experiences, work stress and fasting and risk of preterm birth. In addition to the direct effect of elevated corticotropin-releasing hormone on the initiation of labor, it may have an immunomodulatory effect such that women with high levels of corticotropin-releasing hormone may be more susceptible to infection or the pathological consequences of infection. We review the epidemiological data linking maternal stress, physical stain and fasting to preterm birth and low birth weight and review the plausible biological pathways through which these exposures may increase risk of preterm birth. The timing of these exposures is considered important. Future research and clinical programs addressing these exposures must consider assessments and interventions before pregnancy.

Source III: Human Nutrition. Clinical Nutrition. Metabolic Consequences of Fasting During Ramadan in Pregnant and Lactating Women

In studies in a rural West African village it was observed that all lactating women and 90 per cent of pregnant women fasted throughout the period of Ramadan. The metabolic consequences of this fasting were studied by measuring serum glucose, free fatty acid, triglyceride, beta-hydroxybutyrate, alanine, insulin, glucagon and T3 levels at 0700 h and 1900 h in 22 pregnant, 10 lactating and 10 non-pregnant, non-lactating women. Results were also compared with overnight-fasted values obtained outside Ramadan. Values for the lactating women were not significantly different from the non-pregnant, non-lactating controls despite the additional metabolic stress of lactation. Ramadan-fasted (1900 h) glucose values from women in late pregnancy (3.01 +/- 0.11 mmol/l) were significantly lower than all other groups (P less than 0.01) and were 15 per cent (P less than 0.01) lower than overnight-fasted values from similar subjects. Ramadan-fasted free fatty acid and beta-hydroxybutyrate levels were significantly higher (P less than 0.05) and alanine values were significantly lower (P less than 0.05) in late than in early pregnancy. It is concluded that the phenomenon of ‘accelerated starvation’ occurs when women in late pregnancy fast during Ramadan. The possible consequences of this failure to maintain glucose homoeostasis are discussed with reference to the poor outcome of the actual pregnancies studied.

Source IV: American Journal of Obstetrics and Gynecology: Prolonged periods without food intake during pregnancy increase risk for elevated maternal corticotropin-releasing hormone concentrations.

Objective: Fasting during pregnancy stimulates preterm delivery in animals and increases women’s risk for preterm delivery. Fasting stimulates hypothalamic corticotropin-releasing hormone production in animals. Elevated maternal corticotropin-releasing hormone concentrations are associated with preterm birth. We hypothesized that prolonged periods without food during pregnancy increase maternal corticotropin-releasing hormone concentrations, which lead to preterm delivery.Study Design: In the Behavior in Pregnancy Study, we examined prolonged periods without eating during pregnancy and corticotropin-releasing hormone concentrations and gestational age at delivery with multivariate logistic regression analysis (n = 237).Results: Prolonged periods without food lasting 13 hours or longer were associated with elevated maternal corticotropin-releasing hormone concentrations compared with prolonged periods without food lasting less than 13 hours at two time points during pregnancy, controlling for pregravid body mass index, energy intake, income, race, smoking, and maternal age (18-20 weeks: adjusted odds ratio, 2.5; 95% CI, 0.9-7.1; 28-30 weeks: adjusted odds ratio, 1.7; 95% CI, 0.7-4.2). There was an inverse, linear relationship between maternal corticotropin-releasing hormone concentrations and gestational age at delivery.Conclusions: Prolonged periods without food intake during pregnancy are associated with elevated maternal corticotropin-releasing hormone concentrations and with preterm delivery. (Am J Obstet Gynecol 2001;185:403-12.)

The following two sources are more recent than Waxman’s post:

Source V: Placenta: Changes in Placental Size During Ramadan.

AbstractBACKGROUND: Placental growth responds to maternal influences. Ramadan is an annual period of day-time fasting during which people in Saudi Arabia, including pregnant women, change their diets and physical activity. Little is known about the effects of this altered lifestyle on placental development.

METHODS: We studied the birth records of 7083 babies born over a four-year period to Saudi nationals in Unizah, a small city 350 km to the north of Riyadh, the capital city of Saudi Arabia. The records included birth weight, placental weight and gestational age.

RESULTS: Mean birth weight was similar to European values but the mean placental weight and ratio of placental weight to birth weight were lower. Among babies who were in the second or third trimester of gestation during Ramadan the mean placental weight and ratio were below those of babies who were not in utero during Ramadan. Among boys the mean placental ratios were 14.4 percent (second trimester) and 14.5 percent (third trimester) compared with 14.9 percent (p=<0.001 and 0.002). The corresponding figures for girls were 14.8 and 14.6 percent compared with 15.1 percent (p=0.02 and <0.001).

CONCLUSIONS: In Saudi Arabia placentas respond to mothers’ limited ability to deliver nutrients to them. Placental growth slows but efficiency is increased so that fetal growth is sustained, albeit with a reduced reserve capacity. The lifestyle changes associated with Ramadan further slow placental growth. Ramadan may influence placental growth through dietary changes other than day-time fasting. Changes in placental growth during Ramadan could be associated with altered fetal programming, and may therefore have long-term implications for the health of the next generation.

Source VI: This BBC article refers to a recommendation that Muslim women not fast during Ramadan, based on a new study:

A study by scientists in the United States, based on census data from the US, Iraq and Uganda, found that pregnant women who fast are likely to have smaller babies who are more prone to learning disabilities in adulthood.The researchers from Columbia University found that this trend was most marked if mothers-to-be fasted early on in their pregnancy and during the summer when longer days meant they went more hours without food.


I have not included the many studies that show no effect of fasting during pregnancy, according to the specific parameters measured in the individual studies.

Some of the studies involved fasting during Ramadan. The Ramadan fast is a month long, but only during daylight hours. The Yom Kippur fast only occur once, but for 25 hours straight. Any effect on the mother’s blood chemistry is greater. Another thing to keep in mind is that how well the mother feels is not necessarily an indicator of what is happening. A woman can fast well with no ill effects, but a related complication can occur later in pregnancy or after birth.

When discussing fasting with your rabbi, be sure to mention any difficulties you have had in your pregnancy or in previous pregnancies, or problems when fasting in the past.

Photo credit: Daquella Manera


Rabbi Elgazi’s Ruling (Yom Kippur 2012)

A Radical Ruling: Fasting and Breastfeeding on Yom Kippur (includes information on why supplementing on YK is not always a good idea)

Tips on Breastfeeding and Fasting on Yom Kippur

Fasting When 9 Av Is Postponed (2016)

Fasting During Pregnancy on Yom Kippur


  1. Nurse Yachne says

    When I took Ob-Gyn nursing, the midwives who taught the course all said that they always recommended that pregnant women NOT fast.

    During 2 pregnancies, I fasted until I started having very strong Braxton-Hicks contractions and then started drinking in shiurim.

    Another memorable year, I fasted while feeding a nursing-only baby and started to see flashing lights. I lay down on the floor and it started spinning like a Tilt-a-Whirl too, and guess what, I STILL finished the fast.

    I would never recommend this to anyone else, nor would I wish to take responsibility for what might happen to another pregnant or nursing mother who tried to fast.

    • NY, thanks for sharing your experience. I had no problems fasting, but your last point is why I published this post.

    • Brooklyn Savta says

      This is the problem with telling someone they can fast as long as they “feel okay.” Most people seem to define “feeling okay” to be “as long as I am pretty sure that death is not imminent.” Flashing lights and the floor spinning like Tilt-a-Whirl, was your body’s way of telling you that you should not be fasting!
      Continuing a fast under such conditions is not something to be proud of. If I were you, I would not repeat this story. Women who are pregnant or nursing with much less severe symptoms than that, should not be fasting. Why make them feel like they are weak if they “give in” and protect their babies, instead of endangering them?

  2. I was determined to fast during my second pregnancy. At seven weeks pregnant and nursing my 10-month old, I was inhumanly starving and broke down, almost crazed…but I ate in shiurim. I found out two weeks later that I was actually in my second trimester with twins.

  3. Nurse Yachne says

    “I would have to disagree, though you are of course entitled to your opinion. What do you mean “no observed ill effect?”

    Yow, he’s right. That is not an example of medical or scientific reasoning. “Everybody’s doing it” is just teenagelogic at its worst.

    Another bit of anecdotal evidence–the midwives with whom we studied said there are always higher rates of premature labors and births on and immediately after Yom Kippur and Tisha B’Av.

  4. I’m 7 weeks pregnant with my first child (BH!) but have no idea what I’m going to do this yom kippur! My “morning” sickness is bearable (but let’s not pretend it doesn’t last all day) and while drinking in shiurim may help, eating is really what relieves the nausea. My rabbi is getting back to me on the issue, but this article is helping me seriously consider not fasting all day, given the last study cited which claims that particularly if mothers-to-be fast in earlier pregnancy, there may be detrimental effects.

  5. Thank you so much for this thorough review. I have shared it with a lot of friends. I asked a rav about drinking and eating in shiurim when I was nursing my first child and was given a heter since BM was the primary source of nutrition.

    As a doula, I do have clients (pre- and post-natal) who have asked me about their fast. I sometimes hesitate to tell them to ask, because I worry they will get an answer that might put them or their baby at risk. It definitely helps to find a rav who is also quite knowledgeable about pregnancy and nursing, in particular.

    Gmar Chatima Tova!

  6. Possibly pregnant says

    What about women who could be in the very first weeks of pregnancy– too early to tell for sure? I’ve looked for info about TTC and fasting and can’t find anything. I guess when in doubt, fast?

    • I really don’t know, PP. I asked the rabbi about the different stages of pg, if there was a difference, and he said that it doesn’t matter except perhaps at the very beginning, it might be okay to fast. I don’t know whether you should take that as a definitive answer or not. A doctor that I corresponded with (have asked him for permission to quote) said that the mother should notice physiological signs before there is harm to the baby. I.e. if you fast or eat shiurim pay attention to your body and don’t be foolish if you begin to feel very weak or ill.

  7. When I was pregnant, I asked my OB/GYN about fasting – he had the training to answer about my health and the health of my unborn child. I wouldn’t ask him about Kasruth, so I did not see the logic about asking my rabbi about fasting during pregnancy as he is not a medical doctor.

    • But a doctor who ascribes no value to fasting will give a one-sided answer: “Of course a pregnant woman shouldn’t fast since it *might* be harmful to the baby.” There needs to be input from both elements.

      • That is incorrect reasoning. We don’t not ask rabbanim for a second opinion or input in case a Dr might be “biased”. Aviva Hadas is correct and in compliance with Halakha: you ask a specialist (Dr). A Rabbi is not a medical specialist. We go to rabbis WITH the specialist’s opinion and a rabbi, with that information then tells you how you can try to fit that in with respecting the fast (example: eating in shiurim when possible, which isn’t considered breaking the fast OR if health requires, not fasting AT ALL since risking your life is assur)

  8. Why is there no discussion of the spiritual consequences of not fasting on Yom Kippur? After all, the only reason to fast is to fulfill a mitzva. That’s why we consult with Rabbis and not only with doctors when deciding who should fast and who is exempt from fasting.

    When I was pregnant the first time I called my Rabbi to ask if I should fast. He asked me how I felt, and if there was anything unusual about the pregnancy or any special health circumstances he should know about. Baruch Hashem there were none. Once he knew that, he explained to me that pregnancy is generally a sign of good health, and that I could be especially thankful this Yom Kippur: for being Jewish, for being married, for being healthy and even pregnant…and that fasting with Klal Yisrael is a wonderful and important thing to do even if it is difficult. I have been fasted safely through many fasts since then, pregnant and otherwise, and am thankful for the spiritual perspective he gave me on fasting.

    I would also add that, when pregnant, we are doubly blessed: we are alive and also giving new life. So pregnancy can be an opportunity to grow in our understanding and commitment to doing Hashem’s will.

    I think the point quoted from the Nishmat web site–that those who are exempt from fasting should be reassured they they, too, are fulfilling an important mitzva– is relevant and important.

    Whether or not to fast is primarily a spiritual / halachic question, not a scientific one, which includes but is not limited to health considerations.

    Gmar Hatima Tova!

    • Hi AR,
      When discussing whether a diabetic should fast, no one talks about the spiritual benefit of the fast, just the halachah. I am assuming that all of us understand the importance and significance of the mitzvah of fasting. By putting too much emphasis on the spiritual aspect, we risk encouraging people to fast (or continue their fast) when they shouldn’t.

      The studies may not be reliable, or relevant. But there is enough evidence to persuade at least one well-respected rabbi to rule that pregnant and nursing women should eat with shiurim. Whether or not everyone agrees, I think it’s important that the information is out there.

      The question of whether or not the fast is difficult, or spiritually rewarding, is irrelevant when making the decision about fasting relating to health. The only question should be concerning the health of the mother and fetus/baby. Pikuach nefesh.

      I definitely agree that those who must eat or drink on YK for health reasons should feel just as much a part of Klal Israel and are observing YK to the same degree as those who fast completely.

  9. Thank you Hannah, for the thorough research you’ve done for all of us.

    Personally, I would not give too much weight to studies that were done on women that fasted for an entire month (daytime only, I know), as a basis of comparison for a 1-day fast.

    The accumulated effects of such a long fast, cant be completely used as a basis of comparison for out fast.

    I would, however, give more weight to the testimonies that were brought here, along with other testimonies that I’ve heard along the years, that clearly show that pregnant women have a harder time fasting, and numerous researches that found out that maternal stress can have a direct effect over the yet-to-be-born child.

    Remember: when you’re spinning around, semi passed-out, and viewing the northern lights in the middle of the day, then apart of the unique psychedelic experience that you are going through, there is a poor child that suffers inside you, and might suffer for the rest of his/hers life – just because you wanted to do some experiments on his/hers behalf.

    I say:
    Whenever in doubt: Shiurim!

    Have an easy fast, mothers to be, and Chatima Tova to us all!

    • Thanks, Swizz.
      You could be right, that the effect of YK is not as great as that of Ramadan. That’s why I quoted the abstracts of the studies, so people could see for themselves. Also, studies aren’t always reliable and are often repeated in different setting for confirmation. Gmar Chatima Tova to you as well.

  10. Is zero-risk the standard?

    We do plenty of mitzvot that involve some risk. Pregnancy and childbirth involve much more significant risk (as compared to not being pregnant) than any additional risk from fasting.

    Is fasting a zero-risk activity for healthy people who are not pregnant?

    Is fasting when pregnant different because the risk is (also) to the baby? (That logic might lead to stricter requirements in the first 40 days.) We give our baby boys a brit, even though it is not risk free.

    I agree with AR (and disagree with Aviva-Hadas) that there need to be two sides to the equation, and that the value of fasting requires one to take on an acceptable level of risk, but not an unacceptable level.

    Defining what level of risk is acceptable requires both medical and spiritual input.

    • Welcome, JN.
      I agree that there is never zero risk. We believe that the benefit of a brit for the baby outweighs the risk. But what is the benefit to the fetus if the mother fasts? I suppose you could argue that there is spiritual benefit, but then why don’t we expect small children to fast? And the mother herself is also at greater risk of complications, say dehydration or UTI, by virtue of her pregnancy, irrespective of the fetus (which might be an argument for eating shiurim even earlier than 40 days). Although a UTI in the mother can cause
      Fasting isn’t a zero risk activity for healthy people who are not pregnant, but when they cease being healthy the risk moves up to a certain point they become exempt from fasting.
      There are two issues: Is the woman going to fast? And if so, at what point should she break her fast? Surely she should start drinking at some point before she ends up in the delivery room with premature labor.

  11. I respect very much the psak of Rabbi Rabinovich, he is somebody with broad shoulders and I am a nobody to argue with him. I have to say, thought, that as a regular reader and admirer of this blog, (although I am a slacker of a commenter), I am concerned at the implications of this post.
    A quick reading of the post, really can be interpreted that pregnant\nursing women SHOULD NEVER fast, and in fact are putting their fetuses\children at major risk by doing so, and that is why the psak was issued, based on the latest medical information.
    This is dangerous information to put out there. I see no reason, that a woman who has common sense should not continue to do what all cholim\pregnant\nursing women have done and continue to do with regards to fasting, and that is, have a specific conversation with both a trusted knowledgeable health care provider and personal Rabbi. My husband is a pulpit rabbi, and spends much time the days leading up to any fast answering these types of shailos. He is very careful to first find out what the doctor’s sense is, and his psak just about every time is, do what your doctor tells you to do, and if fasting, make sure to find out what parameters your doctor feels warrant breaking a fast, and if shiurim or full eating\drinking are necessary. He often consults with frum doctors as well, as needed.
    On a more personal note, I have fasted at many various stages of pregnancy, and have done so with the direct approval of an OB, and have broken my fast when necessary (well before any major health risk is going on–any faintness\nausea\etc). I have also spent many of those fasts barely moving more than necessary, and found babysitting help etc. to make that happen, to allow myself to fast. My husband has paskened for families that it is better for a husband to stay home from shul to help with kids if the alternative is for the mother to probably have to break her fast.
    All this to say, I think that unless R’ Rabinovich is one’s personal Posek, I am uneasy with people deciding to follow this psak on their own accord. I also wonder, respectfully, whether his Psak is meant to take care of a certain type of person, who is not going to be able to be moderate in their approach, and needs more of an all or nothing (sort of like certain recommendations from the American Academy of Pediatrics, that assume a very low level of parental ability\competence and make recommendations to protect all children). Meaning, is it easier to just say “no pregnant\nursing women fast”, than to have individual women be willing to ask the shaila, accept the answer when it is no, and be willing to break their fast in the middle if they are fasting, as opposed to pushing through, which is dangerous?

    Obviously, if there were some real, large, accepted studies that all fetuses are put at a real level of risk from one day of fasting, that would change things radically. But, honestly, as a total non-medical professional, I can’t imagine that is the case. As my first OB often told me, fetuses are just not AS fragile as we think they are.
    Gmar Chatima Tova, I hope that this comes across as a respecful difference of opinion, and not any kind of attack, G-d forbid, on Erev Yom Kippur. I just kept thinking about this post all day, and felt like it was important to express my approach.

    • Chaya,
      Your comments were respectful and I appreciate your taking the time to write them out so thoughtfully.
      After speaking with a rabbi and a doctor, I don’t feel that I can comfortably say that it’s okay for a healthy woman to fast completely. It may be, but I don’t have enough information. If that makes me irresponsible, so be it. I’m not a rabbi. I see my role as supporting mothers and giving them information, especially information that they may not get elsewhere. I’ve seen advice on the internet quoting a study or two showing that fasting is fine. I wanted to show that there is another side.
      I hear your point about the AAP. The doctor I spoke to said as much, that with such a strong psak perhaps the women who really shouldn’t fast, won’t, and it is worth it being out there just for that.
      Gmar chatima tova.

  12. forgive the late comment, but all these comments and posts were percolating in my mind and it triggered a memory –

    there were very excellent studies done on the Dutch, who semi-starved for periods of time during WWII. Apparently episodes of fasting/limited food intake were shown to affect the way genes were expressed in both the children and the grandchildren of Dutch women who lived through the periods of starvation in WWII. (The scientific term is “epigenetic effects”.)

    Obviously one 25 hour fast is different than a month of semi-fasting, ala Ramadan, or weeks/months of limited food intake, as in the Dutch WWII experience. But it is worth considering. There are many aspects of fetal development still unknown by science or rabbinics.

  13. I think that adherence to certain requirements may be a tad archaic, especially since there is now knowledge that fasting does affect both mother and child negatively.

    The rabbi I consult with tries to convince pregnant women and those with health conditions not to fast at all, and as the only person in my area schooled in the Laws I tend to agree.

    These are the commandments we live but do not die by.

  14. The studies you cited are not really relevant for women who are only fasting for one 25-hour period.

    One of the things that helps pregnant/nursing mothers is to take kal li tzom or tzom kal or one of the other herbal preparations that are meant for pregnant or nursing mothers. They help tremendously and they even leave the nursing mother with a great milk supply all through the fast to the very end. I assume that whatever OBs you spoke to do not have sufficient experience in herbal medicine to know about these things, but as an ND I recommend them very strongly.

    Another point is that not only is a YK fast different from other types of fasts that other peoples of the world do in duration, it is also different in terms of the fact that since Hashem has ordered us to fast He also can make sure that mother/baby do not suffer any ill effects — surely you don’t think that such a small thing is too hard for Hashem to manage!

    A gut gebentched ya’ar to you and all.

    • Hi RF,
      Thanks for your visit.
      1.”The studies you cited are not really relevant for women who are only fasting for one 25-hour period.” It’s possible you’re right. So far there are not many studies about 25-hour fasts.
      2. I have heard of many cases of people taking herbal preparations who ended up being quite ill during the fast. And I personally think that a pregnant or nursing mother should be doubly wary about ingesting herbal preparations. Just because something is labeled as safe, doesn’t mean it is.
      3. Hashem is in charge, true, but the fact is that many people are religiously exempt from fasting. See some of the earlier comments.

      • 2. A pregnant woman should indeed be wary of ingesting anything at all except for food and water, but that does not mean that herbal preparations are not useful and effective for healthy pregnant/nusrsing women. Every woman should check out anything she wants to ingest with a qualified medical professional [an MD for pharmaceuticals or an ND for herbal meds] to make sure that she does not have any health condition that would cause any med to be contraindicated.

        3. But otherwise healthy pregnant and nursing mothers are NOT exempted from fasting on YK. There are health conditions that can cause one not to be allowed to fast, but these are not blanket exemptions and must be checked out with one’s own posek and OB.

        • RF, what are the qualifications of an ND?
          Some rabbis do give a blanket heter to eat a minimal amount, as I have quoted. But in any case, to say that Hashem will make sure a pregnant woman comes to no harm is not a halachic approach.

          • An ND [at least where I studied] must study 4 years of med school medicine in addition to herbal medicine, nutrition, aromatherapy, Chinese medicine and other courses.

            As far as what is a halachic approach, it depends on your rav and your hashkafa. There are some rabbonim who give a blanket heter for shiurim but there are others that disagree. Everyone must consult their own posek and their own health professional.

  15. i simply don’t understand why a rav has any role in deciding whether a pregnant woman should fast. this is a question for the ob. if he says no, only then go to a rav and inquire about shiurim, etc. which should then still be confirmed with the ob. (my wife fasted with both of our kids with the blessings different obs. each time)

    “Any effect on the mother’s blood chemistry is greater.”

    says who? why the assumption that fasting for 25 hours once is worse than 12-17 hours daily for a month?

    and most of the studies cited in the post (at least as far as indicated by the abstracts) have no relevance to whether healthy jewish women with uncomplicated pregnancies in first-world countries who get proper pre-natal care can fast once for 25 hours.

    shavuah tov

    • Abba: I’m not assuming that one is worse than the other, just bringing up the possibility. There are delicate points during the development of the fetus, which is why alcohol can cause damage at some stages of pregnancy and not others. And the effect on blood chemistry is greater for that one day of YK or 9 Av, than one day of a Ramadan fast. In theory it could have a greater effect.

      • “And the effect on blood chemistry is greater for that one day of YK or 9 Av, than one day of a Ramadan fast.”

        but the studies are taking into account the *cumulative* effects of a month of daily fasting?

        “In theory it could have a greater effect”

        i don’t know how it works in israel, but in america doctors, and obs particularly, are terrified of lawsuits. i can’t believe that most obs (admittedly anecdotal evidence from the experiences of friends and acquainances who asked an ob) would permit fasting if such a theory really had something behind it.


    “Another bit of anecdotal evidence–the midwives with whom we studied said there are always higher rates of premature labors and births on and immediately after Yom Kippur and Tisha B’Av.”

    if by premature you mean preterm, then why take anecdotal evidence over scientific evidence? fasting may induce labor, but not iirc preterm.

  17. incidentally, there is apparently another option. a friend called me a few days ago to find out where to get IV tubing for a pregnant patient of his who wanted it so she could fast.

  18. Actually, I’m not sure, because not all Muslim women fast every day. My point (purely theoretical) is that the critical point that causes concern could be reached the longer you fast. And eating at night gives the woman a chance to recover. There may not be a cumulative effect.

  19. I believe that I am the anonymous commenter you quoted from Parshablog’s post. My comment that you quote was part of a series of comments, and I only said in the part you quote that I believe that *shomer psaim hashem” kicks in. Alternatively, not that concept, but simply that there is insufficient evidence (at least judging by what was cited in the original parshablog post and comments) to overturn the baseline halacha – and this is only opinion, based on what I read on the internet! My point was that given that the studies I saw cited at that point included only one w/ jewish women who fasted one day, and that I understand that this study didn’t show harm to most pregnant women, I therefore presume that the baseline halachic assumption is that there is no evidence of harm in most cases (not discussing specific women whose drs say otherwise in their case!!!). I don’t know what R Rabinowitz says as I have not seen his teshuva. However, I know that he is a talmid chacham of stature. It’s true that right now, I doubt that a single 25 hour fast is harmful for most cases; many of us were born to mothers who fasted on yom kippur. Of course we dont know if we were harmed, or about alternative universes with miscarriages etc as Josh Waxman said. We probably can’t know about the effects of fasting on all stages of pregnancy and nursing without careful studies. Still I believe that only one study that directly applies (that was done on pregnanat women in Israel) was discussed on JoshWaxman’s blog, and in my understanding, which may be faulty, it did NOT indicate that most women were harmed by the fast. So I simply don’t understand why the halacha should assume that they are harmed, based on studies on Ramadan fasters etc. I do understand why more studies can be done and the evidence reevaluated in future. I certainly wish someone would post R Rabinowitz’ teshuva, since he apparently thinks differently than me, and either has different studies that he’s seen and may quote, or else has a different analysis of the halacha, and I grant everyone here that he is a much greater scholar than I am. I just wrote what I think, I trust everyone knows not to follow anonymous commenters on the internet for halacha, esp not me, esp. not medical halacha, esp. when to the best of my knowledge no one has posted the relevant teshuva yet, esp when i have no idea if i have seen the relevant studies. just consult your rabbis and drs, as you all know to do, as it matters not a whit what I said or say:)
    I also intended and intend absolutely no offense to anyone, from R Rabinowitz, to the hostess of this blog, to Josh Waxman or to anyone else
    a gmar tov and a good year, and a year of good health for all

    • me:
      I will try to post a copy of the teshuva. No offense taken. Yours was a common response to the psak, or to many innovations including medical–it’s been done this way for thousands of years, and I liked the way Josh Waxman addressed the point. Gmar tov to you.

  20. The Nishmat site quotes a study claiming that “most” births after the fast were not preterm. R. Rabinovich apparently feels it is still a concern. Nishmat on preterm labor:
    “It should be noted that 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 towards 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 women. Thus, most healthy pregnant women must fast.”

  21. As an afterword… I observed myself (a lactating woman) during the fast. My 20 month old was very needy on Yom Kippur for whatever reason and wanted to nurse frequently and be held and play etc etc and it was terribly exhausting and I felt quite ill.

  22. which was not at all my experience pre-motherhood — fasting was much different and promoted spiritual reflection.

  23. I wanted to update you that I had a mom of a 10 month old who is a few months pregnant call me just a few hours before Yom Kippur. She was unsure about fasting, unsure about how she should eat in shiurim if she ate, and felt a LOT of pressure from others in person and on line to do one thing or another. It was so great to be able to send her here and let her read different opinions and feel empowered to go by her doctor’s wishes. I don’t even know if she fasted in the end, but I do know she felt a lot better going into her Yom Tov….

  24. Hi, I have just stumbled upon your blog and wish had done so a week ago- pre Yom Kippur! Prior to the fast I did internet searches on fasting while pregnant (22 weeks) but found so many conflicting views that I just went with my gut- as is my parenting style. I began by fasting but by mid-day, after caring for my toddler while hubby was in synagogue all day, I decided to have some kitkah toast and water! If I had read this blog and what your supportive, spiritual, connected, realistic commentors have said, I would have found someone to help with my son, taken it easier, and pushed through the fast! I am strong and healthy baruch hashem so I could have done it I’m sure… Well I’ll be keeping a closer check on your lovely blog from now on so as not to miss out on more important info! Regards, Terri

  25. Just wanted to update (I was not able to get back here earlier.)

    I had a difficult time getting pregnant (IVF was the answer finally), I was an older first time mother (which put me into a higher risk category) & I developed gestational diabetes during my pregnancy.

    All of which were part of my decision to ask my doctor about fasting rather than my rabbi.

  26. Fasting is not really advisable to pregnant women. You need to eat to be able to supply your nutritional needs that you can only fill in by eating. It’s a bit confusing if diet will compromise your babies situation.

  27. Very interesting post and comments. When I was pregnant with my son four years ago, Yom Kippur came along when I was 37 weeks. I had a very hard pregnancy – no complications and totally healthy but awful awful ‘morning’ (ha!) sickness and at the same time, crazy hunger. I asked our rav about fasting, less because I worried about the health of the baby since I was almost at term, but because I didn’t want to go into labour pre-term, and because I simply didn’t think I’d be able to fast. When I’m pregnant, the hunger I feel is totally different to ‘regular’ hunger and I literally feel like someone is tearing out my insides if I don’t eat when I’m hungry. And ignoring it for a few minutes doesn’t help – I just keep feeling it. I felt physically incapable of doing it. My rav told me that *I* am the final judge of whether I am capable of fasting, and even if a doctor said I was able to fast, if *I* didn’t think I could/should, then I shouldn’t – and he added that I don’t even have to eat or drink in shiurim.

    In the end I decided I would eat and drink in shiurim. I wanted to ‘feel’ the day at least somehow. Physically I felt ok, but a few hours after the fast ended, my waters broke. So in the end my son was born 2.5 weeks early the day after Yom Kippur. 37 weeks is officially ‘at term’ even though it’s early, so it wasn’t quite premature. And of course I can’t know if the reduced food and drink I ate had anything to do with when my waters broke or if it would have happened anyway.

    I am now 22 weeks pregnant with my second child, so will be 23/24 weeks pregnant by Yom Kippur. I am not planning on fasting, or even on eating in shiurim. I am too scared of what might happen. My pregnancy is healthy again (although the sickness was even worse this time, but has now, for the most part, passed), but I had trouble conceiving this time round. We were on the verge of starting treatment when I finally got pregnant after 19 months of trying. And I’m 39, not exactly a spring chicken. Aside from the hunger issues – which are exactly the same as last time, *and* the fact that this time I won’t be able to just lie down and rest as I’ll be looking after my (almost) four year old, I am just not prepared to risk my child at 23 weeks, because I have no idea whether the eating/drinking in shiurim last time brought on labour or not. And labour at 23 weeks is obviously vastly different to labour at 37 weeks. Even if I could manage the crazy hunger, I’d be so stressed out from worrying about what I might be potentially causing that I just couldn’t do it. Of course I have my rav’s psak to depend on. Thankfully he is a wonderfully wise man who really does teach “vechay bahem.”

    It is definitely strange not to fast on yom kippur and I’m glad for those commenters who said that a woman should still feel part of the community. Of course that can be hard even when you *are* fasting, if you are a mother of young children and your focus becomes looking after them rather than teshuva and the meaning of the day!

    Just my $0.2


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