Yevamot 72a~ Blood letting and permissive anemia

“ א”ר פפא הלכך יומא דעיבא ויומא דשותא לא מהלינן ביה ולא מסוכרינן ביה והאידנא דדשו בה רבים שומר פתאים ה’
Rav Pappa said...we should not circumcise on a cloudy day or on a day of severe south winds, and we should not let blood on these days. But now that so many people do in fact do these procedures on these days we can apply the principle “God protects this simple”
”

— Yevamot 72a

Blood-letting was a simple enough and rather brutal procedure. You went to the blood letter and he sliced into your vein. After a while, when the blood-letter had determined that you'd lost just the right amount of blood, the wound was bandaged, and off you went, looking forward to being cured of whatever had led you to the blood-letter in the the first place. The procedure was thought to be the way to cure any number of illnesses, including fever and  asphyxia (Yoma 84a). It dates back at least to the 5th century BCE, and is mentioned in the writings of Erasistratus (300-260 BCE) who opposed the procedure, and Galen (c. 130-200 CE) who used it and taught that it was an important tool that could heal the sick.

Blood-letting is frequently mentioned in the Talmud. Most famously, in Shabbat 129a, there is an extensive discussion of some of the do's and dont's of blood letting:

Rab Judah said in Rab's name: One should always sell [even] the beams of his house and buy shoes for his feet. If one has let blood and has nothing to eat, let him sell the shoes from off his feet and provide the requirements of a meal therewith. What are the requirements of a meal? — Rab said: Meat; while Samuel said: Wine. Rab said meat: life for life. While Samuel said, Wine: red [wine] to replace red [blood]. ..For Samuel on the day he was bled  a dish of pieces of meat was prepared; R. Johanan drank until the smell [of the wine] issued from his ears; R. Nahman drank until his milt swam [in wine]; R. Joseph drank until it [the smell] issued from the puncture of bleeding. Raba sought Wine of a [vine] that had had three [changes of] foliage.

…Rab and Samuel both Say: If one makes light of the meal after bleeding his food will be made light of by Heaven, for they say; He has no compassion for his own life, shall I have compassion upon him!

Rab and Samuel both say: He who is bled, let him, not sit where a wind can enfold [him], lest the cupper drained him [of blood] and reduced it to [just] a revi’it,  and the wind come and drain him [still further], and thus he is in danger.

Samuel was accustomed to be bled in a house [whose wall consisted] of seven whole bricks,  and a half brick [in thickness]. One day he bled and felt himself [weak]; he examined [the wall] and found a half-brick missing.

Rab and Samuel both say: He who is bled must [first] partake of something and then go out; for if he does not eat anything, if he meets a corpse his face will turn green; if he meets a homicide he will die; and if he meets swine, it [the meeting] is harmful in respect of something else.

Rab and Samuel both say: One who is bled should tarry awhile and then rise, for a Master said: In five cases one is nearer to death than to life. And these are they: When one eats and [immediately] rises, drinks and rises, sleeps and rises, lets blood and rises, and cohabits and rises.

Samuel said: The correct interval for blood-letting is every thirty days. Samuel also said: The correct time for bloodletting is on a Sunday Wednesday and Friday, but not on Monday or Thursday…

There is absolutely no place for this intervention today, other than for the rare illness called polycythemia vera.  In this illness, the body makes too many red blood cells (hence its name, poly=many, kytos=cells, hamia=blood), and one way to keep the illness in check is to remove those excess blood cells at a regular intervals.  But other than for this disease, blood-letting, (called today phlebotomy or venepuncture, which do sound a whole lot more palatable but describe the same procedure) is harmful. Do not try this at home.  

Having made this very clear, let's introduce some nuance. Palliative blood-letting may be useless, but from this is does not follow that it is a good idea to restore the hematocrit (the concentration of red blood cells in the blood) to normal in every disease state. For example, virtually all patients on  dialysis (due to chronic kidney disease) become anemic, but in these patients, trying to restore the hemoglobin concentration to a higher level (~13g/dL for those interested) seems to be associated with increased risk, when compared with those in whom the hemoglobin level was lower. And when tiny premature babies get anemic, there does not seem to be an advantage to keeping the hemoglobin in a higher range (though to be fair, more research needs to be done). But these two examples do not in any way lend support to the notion that blood-letting is anything other than a bad idea.  

Photo of bloodletting in 1860.  Yes, that's right, 1860.  From the Burns Archive

The procedure, which had been in use for at least 2,000 years, only stopped being part of standard medical practice in the late 19th century.  Writing in 1875, one Englishman could not bring himself to believe that the era of blood-letting was really  over. "Is the relinquishment of bleeding final?" he wrote, 

or shall we see by and by, or will our successors see, a resumption of the practice? This, I take it, is a very difficult question to answer; and he would be a very bold man who, after looking carefully through the history of the past, would venture to assert that bleeding will not be profitably employed any more.

(In fact, blood letting was even suggested as a therapy during a severe influenza outbreak at a British Army camp in northern France in the winter of 1916-17.  Amazing.) While we no-longer practice this all but useless intervention, the prayer associated with it is worth recalling. Maimonides ruled (Berakhot 10:21) that before undergoing blood-letting, the patient pray the procedure be effective,and this ruling is found as part of normative Jewish practice, recorded in the שולחן ערוך אורח חיים רל ס׳ק ד:

הנכנס להקיז דם אומר "יהי רצון מלפניך ה' אלהי שיהא עסק זה לי לרפואה כי רופא חנם אתה". ולאחר שהקיז אומר "ברוך רופא חולים

Before undergoing blood letting say: May it be your will Lord my God, that this procedure will heal me, for you are an unconditional healer. And when it is finished he says: Blessed are you God, healer of the sick.

The procedures have changed, but the prayers have stayed the same.

Yevamot 64b ~ Urinary Tract Infections, and the Class That Went On For Too Long

יבמות סד,ב

רב גידל איעקר מפרקיה דרב הונא רבי חלבו איעקר מפרקיה דרב הונא רב ששת איעקר מפרקיה דרב הונא

Rav Gidel became sterile on account of Rav Huna's lectures, Rav Chelbo became sterile on account of Rav Huna's lectures and Rav Sheshet became sterile on account of Rav Huna's lectures...

Rav Huna had a lot to answer for.  His lectures went on, and on, and on, and on and on and on.  A couple of pages prior, on Yevamot 62b, Rashi explained the relationship between these lengthy classes and infertility:

איעקר מפרקיה דרב הונא.שהיה מאריך בדרשיו וצריכים למי רגלים ומעמידים עצמן ונעקרים כדתניא בבכורות 

The suggestion here is that holding-it-in can lead to problems of fertility, and there is a least a theoretical reason why Rav Huna's lengthy classes had the unintended consequence of lowering the reproductive rates of his students.  There is a clear relationship between male infertility and repeated infections of the genitourinary tract. Here, for example, is  how one urology textbook opens its chapter on male genital tract infections and infertility:

Male Genital Tract Infections and Infertility. Neal, DE, Weinstein, SH. In Male Reproductive Dysfunction ed Kandeel FR. Informa Healthcare 2007

Any male GU infection such as prostatitis, urethritis or epididymo-orchitis can reduce both sperm count and the quality of the seminal fluid. OK, but what does that have to do with not urinating when you feel the urge? Well here's the thing: that not-going-when-you-need-to is not a good idea.

It's quite a challenge to determine scientifically the effect of holding-it-in (and hereafter referred to as delayed micturition, because it sounds nicer) on the risk of getting a urinary tract infection.  You can't very easily randomly assign one large group of healthy volunteers to urinating whenever they want, and a second to urinating only three times a day.

However, there are a couple of observational studies that may be able to tell us something about the risk of delayed micturition.  A 1968 study of 112 women with a documented UTI reported that further UTIs could be reduced by voiding  every two hours during the day (which sounds rather too good to be true). And a 1979 study from the (not-very-widely-read-but-it-really-is-a-journal) Scandinavian Journal of Urology and Nephrology reported that the frequency of UTI was significantly higher among women with three or less voidings per day compared with those who have to go four or more times per day. (Whether this is true for women outside of northern Jutland where the study was conducted remains unclear.)

So a decreased voiding frequency is associated with an increased number of infections, and urinary tract infections are associated with decreased fertility. Thus by the rule of transitive relations (or something clever like it) decreased voiding may indeed be associated in a causative way with decreased fertility.  

All this is highly speculative, and it would certainly be unusual for male sterility to directly result from delayed micturition.  But here's the weird thing: teachers are slightly more likely to suffer urinary tract infections when compared with the general population. Is that because they too, like their students, hold-it-in? (Yes, I know it didn't reach statistical significance, but the authors thought it was important to note, and so do I.)   

Kovess-Masféty, V. Do teachers have more health problems? Results from a French cross-sectional survey. BMC Public Health 20066:101;1-13

Poor Rav Huna, talking on and on and on, while his miserable students had to sit there with their legs crossed and could likely only think of only one thing. We will give the last word to Rav Acha bar Yaakov, another hapless student of Rav Huna. 

אמר רב אחא בר יעקב שיתין סבי הוינא וכולהו איעקור מפרקיה דרב הונא לבר מאנא

Rav Acha bar Yaakov said, we were a group of sixty students, and all of us became sterile because of Rav Huna's lectures - except me (Yevamot 64b).

Students be warned.

Yevamot 64b~ Circumcision, death, and Hemophilia A

תניא מלה הראשון ומת שני ומת שלישי לא תמול דברי רבי רבן שמעון בן גמליאל אומר שלישי תמול רביעי לא תמול... א"ר יוחנן מעשה בארבע אחיות בצפורי שמלה ראשונה ומת שניה ומת שלישית ומת רביעית באת לפני רבן שמעון בן גמליאל אמר לה אל תמולי

It was taught: If she circumcised her first son and he died, and her second son and he too died, she should not circumcise her third son, so taught Rebbi.  Rabbi Shimon ben Gamliel stated that she should indeed circumcise her third child, but [if he died] she must not circumcise her forth...Rabbi Yochanan said that there was once a case in Zippori in which four sisters had sons:  The first sister circumcised her son and he died, the second sister circumcised her son and he died, the third sister circumcised her son and he died, and the forth sister came to Rabbi Shimon ben Gamliel and he told her "you must not circumcise your son" (Yevamot 64:)

The Talmud here is describing a disease that is affected through the maternal line (hence the four sisters - all of whom seem to pass this disease on to their male children). The disease is X-linked Hemophilia A; the term X-linked indicates that the faulty gene is carried on the X chromosome, which is men is always inherited from the mother. Hemophilia A is an X-linked recessive genetic disease, first described by the American physician John Conrad Otto, who in 1803 described a bleeding disorder that ran in families and mostly affected the men. John Hay from Massachusetts published an account of a "remarkable hemorrhagic disposition" in the New England Journal of Medicine in 1813.

Hay, John. Account of a Remarkable Haemorrhagic Disposition, Existing in Many Individuals of the Same Family. New England Journal of Medicine 1813:2;3;221-225.

 If the mother is a carrier  - as were each of the four sisters in Zippori - then she has a one in four chance of passing on the disease to a child, and that affected child will always be a son:

Courtesy NHLBI

The rabbis argued over a technical point - that is, how many cases of bleeding are needed to establish a pattern. According to Rebbi (that is  Rebbi Yehuda Ha-Nasi, c. 135-217 CE.) two cases were sufficient, while Rabbi Shimon ben Gamliel insisted on three cases before ruling that there was a life threatening pattern.  Indeed the disease in boys must have been very perplexing, because (as you can see in the diagram above) not every boy would be affected. In fact, if the mother is a carrier and the father is not, there is only a 50% chance of a boy having hemophilia.  It is this fact that perhaps explains the dispute between Rebbi and Rabbi Shimon ben Gamliel regarding how many children need to exhibit the disease before we can assume that any future male child will also have it.  If every boy born in the family would have been a hemophiliac, Rabbi Shimon's ruling would have seemed unnecessarily cruel.  But since by chance, half of the boys born might not have hemophilia, the need to demonstrate the prevalence of the disease (in a society in which its genetic foundations were not known) seems eminently sensible.

In  Hemophilia A there are various genetic mutations that result in low levels of clotting factors. These levels may be only mildly decreased, or so low that severe life threatening hemophilia results. It is treated with transfusions of clotting factors which restore the levels to normal. Although these transfusions must be given several times a week in those with severe disease, there is hope that recombinant clotting factors can lengthen the time between the needed transfusions.

Later in Yevamot, the Mishnah records the case of a priest who was not circumcised -  because of the deaths of his brothers when they underwent the procedure. So this law was certainly practiced, and the Talmud records not only the earliest known description of hemophilia, but the emphasis on the preservation of life as a normative Jewish practice. 

Yevamot 42b~ The dangers of pregnancy while nursing

If a mother becomes pregnant while nursing, her milk supply will become turbid and (unless an alternative is found) her nursing child may die (Yevamot 42:)

סתם מעוברת למניקה קיימא דלמא איעברה ומעכר חלבה וקטלה ליה 

So how good a contraceptive is nursing? In a word (well, actually two words) it depends. In the first 3-6 months after birth, and if the baby is fed only on breast milk, some claim that breast feeding is a pretty good contraceptive, and is effective about 98% of time. But if mum skips a feed here or there, or if mum's periods have re-started, all bets are off.  Here's data from an old paper on the topic. Take a close look at the last column- the failure rates per 100 women.

Prolonged Breastfeeding as a Birth Spacing Method Jeroen K. Van Ginneken. Studies in Family Planning, Vol. 5, No. 6 (Jun., 1974), pp. 201-206

Those are high failure rates -as high as one in five - which makes it a pretty unreliable contraceptive. A review of breastfeeding as a contraceptive was published in 2003 in the widely respected Cochrane Reviews; it concluded that "[f]ully breastfeeding women who remain amenorrheic have a very small risk of becoming pregnant in the first 6 months after delivery when relying on lactational sub fertility". However, - and this is really important - it is not possible to know when amenorrhea is likely to end, and so an IUD is suggested as additional contraception wherever possible.

Overall, the talmudic suggestion that conception is possible while a mother is breastfeeding her child is, scientifically speaking, spot on.