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.

Yevamot 42a~...an eight month fetus cannot survive

“...it is the women who make the judgments and ... insist that the eighth-month babies do not survive, but the others do. ”

— Hippocrates, On the Seventh-Month Child

There is general agreement that a widow must wait a period of time after the death of her husband before re-marrying, to ensure that should she see signs of  pregnancy soon after the death of her first husband, the paternity of the child will not be in doubt.  The Talmud assumes that all pregnancies become obvious within three months of conception, and so a woman can remarry after she waits three months from the death of her first husband.  Shmuel explains the importance of uncontested paternity: 

’משום דאמר קרא: ’להיות לך לאלקים ולזרעך אחריך

  להבחין בין זרעו של ראשון לזרעו של שני  

So far so good. But then the Talmud analyses the viability of a child born prematurely in which the father may be either the first husband who subsequently died, or a second man, to whom the mother re-married very son after the death of her first husband. The Talmud suggests that the women need wait two and a half months after the death of her first husband. If a child is born seven months later, it must have been fathered by the second husband, since (i) if it was fathered by the first husband the gestational period would be nine and a half months, which is assumed to be impossible, and (ii) if it was  fathered by the first husband but was born prematurely, the gestational period would have to have been eight months - and as Rashi explains - an eight month fetus is not viable.  This belief - that a fetus of seven months gestation may survive, but one born in the eighth month of gestation cannot do so - is very odd. But it wasn't a uniquely Jewish belief.

“בר תמניא לא חיי Yevamot 42~...an eight month fetus cannot survive”

— Rashi, Yevamot 42a

Homer's Iliad, written around the 8th century BCE,  records that a seven month fetus could survive. But it is not until Hippocrates (c. 460-370 BCE, or some 500 years before Shmuel), that we find a record of the  belief that a fetus of eight months' gestation cannot survive, while a seventh month fetus (and certainly one of nine month gestation) can.  His Peri Eptamenou (On the Seventh Month Embryo) and Peri Oktamenou (On the Eight-Month Embryo) date from the end of the fifth century BCE, but this belief is viewed with skepticism by Aristotle.

In Egypt, and in some other places where the women are fruitful and are wont to bear and bring forth many children without difficulty, and where the children when born are capable of living even if they be born subject to deformity, in these places the eight-months' children live and are brought up, but in Greece it is only a few of them that survive while most perish. And this being the general experience, when such a child does happen to survive the mother is apt to think that it was not an eight months' child after all, but that she had conceived at an earlier period without being aware of it.

The belief that an eight month fetus cannot survive has a halakhic reification: Maimonides ruled that if a boy was born prematurely in the eighth month of his gestation and the day of his circumcision (8 days after his birth) fell out on shabbat, the circumcision - which otherwise would indeed occur on shabbat, is postponed until Sunday, the ninth day after his birth. 

ומי שנולד בחדש השמיני לעבורו קודם שתגמר ברייתו שהוא כנפל מפני שאינו חי... אין דוחין  השבת אלא נימולין באחד בשבת שהוא   יום תשיעי שלהן     

(הלכות מילה 1:11)

This belief persisted well into the early modern era. Here is a state of the art medical text published in 1636  by John Sadler.  Read what he has to say on the reasons that an eight month fetus cannot survive (and note the name of the publisher at the bottom of the title page-surely somewhat of a rarity then) : 

John Sadler. The Sicke Womans Private Looking Glasse. London 1636. From the Collection of the National Library of Medicine, Bethesda MD

Saturn predominates in the eighth month of pregnancy, and since that planet is "cold and dry"," it destroys the nature of the childe". That, or some odd yearning of the child to be born in the seventh but not the eight month (according to Hippocrates) is the reason that a child born at seven and nine months' gestation may survive, but not one born at after only eight months.

Today, gestational length is of course critical, and, all things being equal, the closer the gestational length is to full term, the greater the likelihood of survival.   We can say with great certainty, that an infant born at 32 weeks or later (that's about eight months) is in fact more likely to survive than one born at 28 weeks (a seven month gestation.) In fact, a seven month fetus has a survival rate of 38-90% (depending on its birthweight), while an eight month fetus has a survival rate of 50-98%. Here is the data, taken from a British study.

Draper Elizabeth S, Manktelow Bradley, Field David J, James David. Prediction of survival for preterm births by weight and gestational age: retrospective population based study  BMJ 1999; 319:1093

More recently, a study from the Technion in Haifa showed that even the last six weeks of pregnancy play a critical role in the development of the fetus. This study found a threefold increase in the infant death rate in those born between  34 and 37 weeks when compared full term babies.  

You can read more on the history of the eight month fetus in a 1988 paper by  Rosemary Reiss and Avner Ash.  From what we have reviewed, the talmudic belief in the unusually low survival rate of an eight month fetus (compared to a seven month one) is one that was widely shared in the ancient world. And one that is not supported by any of the evidence we now have.