Niddah 32a ~ Neonatal Menstruation

In this midst of a complex discussion of the laws of ritual impurity as they apply to an adult woman, the Talmud notes that the same laws apply to a new born infant girl.

נדה לב, א

אשה אין לי אלא אשה תינוקת בת יום אחד לנדה מנין ת"ל ואשה

What is this interpretation of the difference between “a woman” and “and if a woman”? As it is taught in a baraita that from “a woman” I have derived only that the halakhot of menstruation apply to an adult woman. From where do I derive that the halakhot of a menstruating woman also apply to a one-day-old girl? The verse states: “And if a woman.” [when the verse includes young girls through the word “and” it includes even a one-day-old.]

From here.

This ruling is codified by Maimonides in his Mishneh Torah: “קְטַנָּה בַּת יוֹם אֶחָד מְטַמָּא בְּנִדָּה”. By this point you may be asking what case could the Talmud possibly be discussing? And the answer is: a real case.

Don’t Panic - it is not unusual

While it is unlikely that you have previously encountered the phenomenon of newborn menstruation, it is a very well described medical condition. In the English literature it is called “neonatal uterine bleeding” (NUB) or “neonatal menstrual-like bleeding” (NMB;) French authors refer to it as “la crise genitale du nouveau ne” and the Germans as “Neugeborenen genitalkrisen” which is useful to know, I suppose, should you find yourself in Europe with a baby girl who has this condition.

In a review paper titled “Is my baby normal? A review of seemingly worrisome but normal newborn signs, symptoms and behaviors” the authors, who were pediatric emergency physicians (meaning they looked after children - the doctors were themselves were, I think, adult-) noted that

Hormonal fluctuations in the neonatal period can result in changes in the genitourinary area that are concerning to parents. Female infants may experience scant vaginal bleeding due to hormonal withdrawal between the third and seventh day of life.

And here is how the very popular site WebMD explains what is going on:

At 2 or 3 days of age, your daughter may have a little bit of bleeding from her vagina. This is perfectly normal; it is caused by the withdrawal of the hormones she was exposed to in the womb. It will be her first and last menstrual period for another decade or so.

And that’s pretty much all there is to say. It is caused by a progesterone withdrawal in the little girl.

Incidentally there is another phenomenon that is somewhat related. Sometimes new-born baby girls will produce milk from their nipples (and sometimes it can happen in a baby boy). This is called “witchs’ milk,” although the correct medical term is galactorrhea. One study found it in 6% of 640 baby girls examined over a five-month period. It too is a normal finding, caused by the baby’s absorption of her mothers hormones, in this case prolactin, and it usually resolves with a month.

Neonatal uterine bleeding and other problems

So although it is a normal finding in a newborn girl, there is some evidence that neonatal menstruation may be an indicator of gynecological problems that will arise later in life. For example, it may be linked to early-onset endometriosis, a condition in which cells similar to the lining of the uterus grow outside of it, most commonly in the ovaries, but sometimes in the abdomen. And it has also been associated with fetal distress and low birth weight.

Summing this up in the European Journal of Obstetrics & Gynecology and Reproductive Biology, two researchers argued for more research in this phenomenon.

First, available evidence clearly indicates that neonatal bleeding is a menstruation characterized by progesterone withdrawal. Because feto-maternal factors influencing its frequency (fetal growth restriction, preeclampsia) are characterized by a reduced blood supply to the placenta, it seems that…NMB can therefore be used as a marker of intrauterine distress and, as a sign of fetal distress the bleeding requires to be registered in medical notes of all newborns.

Secondly, NMB may represent a sign of increased risk of developing endometriosis during adolescence and, in turn that this form may be more frequently progressive, as shown by several studies. Registration of NMB will allow prospective studies aimed at validating the application to newborns of the menstrual regurgitation theory.

Thirdly, there is a need to revive scientific interest in the neonatal menstrual-like bleeding; an event that possibly plays a role, among others, in the transgenerational evolution of major reproductive disorders and adolescent endometriosis.

Although neonatal uterine bleeding is not common, it certainly occurs, which is why the Talmud explored its ritual ramifications. We should expect nothing less.

“Today, the bleeding is completely neglected and considered an uneventful episode of no clinical significance”

— Brosens, I.Benagiano G. Clinical significance of neonatal menstruation. European Journal of Obstetrics & Gynecology and Reproductive Biology 2016. 196 57–59

Niddah 31a ~ When is a Woman Most Fertile?

Today's daf stays with the theme of gynecology. The Talmud describes a dispute about when a  woman is most fertile. One opinion is that "a woman only conceives close to her period"  (אין אשה מתעברת אלה סמוך לווסתה), and a second opinion is that "a woman only conceives close to her immersion in a mikvah" (אין אשה מתעברת אלה סמוך לטבילתה).  

Medical students spend many hours learning the hormones whose rise and fall causes ovulation.  But understanding the ovulation cycle is the key to understanding this passage in the Talmud, so let's spend a paragraph on...

Ovulation in Humans

There are two important hormones that regulate ovulation in a human. One is called Follicle Stimulation Hormone, or FSH. This is produced in the pituitary gland deep in the brain and it acts on the ovaries to produce follicles, which are little groups of cells that may produce an egg. Under the action of FSH, the ovaries produce many follicles, but usually only one will go on to produce and release an egg. (If more than one follicle releases and egg, and both are fertilized, the result is non-identical twins.)  

A sudden spike in FSH and another hormone called Luteinizing Hormone (LH) cause the winning follicle to release its egg, which floats down the Fallopian Tube and into the uterus. If the egg meets a sperm cell, they unite and start down the pathway to producing a baby. But if no sperm cell is encountered, there is a drop in the level of two other critical hormones, progesterone and estrogen (also known as oestrogen for our British readers). This causes the lining of the uterus to slough off, and menstrual bleeding begins, until the whole cycle begins again.

Diagram from here.

Assuming a twenty-eight day cycle, the FSH-LH peak that trigger ovulation just before or around day fourteen, and ovulation - the release of the egg from the ovaries - occurs soon after.

“Scholars of the ancient world thought that menstruation represented an excess of blood from which the woman must periodically rid herself in order to cleanse her body from noxious substances. Only during the twentieth century has the scientific basis for the menstrual cycle and its hormonal relationships been clarified.”

— Avraham Steinberg. Encyclopedia of Jewish Medical Ethics. Feldehim 2003. Vol II p650.

Counting the Days to Mikveh

As outlined in the Torah (Leviticus 15:19), a menstruating woman is ritually unclean - Niddah - for seven days. After that she undergoes a ritual bathing in a mikveh, and she may resume physical and intimate contact with her husband. However the biblical seven day period was transformed in talmudic and later rabbinic tradition. The result was the addition of another (minimum) of five days to the length of time that a couple must abstain from physical intimacy. As a result, if we assume that day one of the onset of menstruation is the first day of the 28 day average menstrual cycle we discussed above, then the earliest day for a woman to immerse in the mikveh is on day twelve, or two days before ovulation is likely to occur.

The length of the menstrual cycle varies to a remarkable degree among different populations and in different age groups. In women age 19-41 in the US it varies from about 23 to 38 days (with a mean of 31 days.) In Danish women aged 20-35 however, the cycle is about 26-31 days, with a mean of 28 days. And each different cycle length will have its own ovulation day, and each varied ovulation day will effect the day on which conception is most likely.

Cycle length distributions for selected samples from various human populations. The numbers at the far left of each sample identify the corresponding sample and data. From Amy L. Harris & Virginia J. Vitzthum. Darwin's Legacy: An Evolutionary View of Women's Reproductive and Sexual Functioning, The Journal of Sex Research 2013. 50:3-4, 207-246.

The Timing of Sexual Intercourse and the Probability of Conception

The next issue in deciding which of the two opinions in today's page of  Talmud might be correct is this:  on which days around ovulation is a woman most fertile?  This question was addressed in a study published in the esteemed New England Journal of Medicine in 1995. The authors followed 221 healthy woman who were trying to become pregnant (for a total of 625 menstrual cycles!!).  The women kept records of when they had sexual intercourse, and their urine was tested for hormone metabolites to estimate the day of ovulation.  The study found that  "conception occurred only when intercourse took place during a six-day period that ended on the estimated day of ovulation." The authors note that couples who abstain from sexual intercourse until they have evidence of ovulation may miss the opportunity for conception.   

Probability of Conception on Specific Days near the Day of Ovulation.
The bars represent probabilities calculated from data on 129 menstrual cycles in which sexual intercourse was recorded to have occurred on only a single day during the six-day interval ending on the day of ovulation (day 0). The solid line shows daily probabilities based on all 625 cycles, as estimated by a statistical model. From Wilcox A. et al. Timing of sexual intercourse in relation to ovulation. N Engl J Med 1995;333:1517-21.

As you can see in the graph below, the day on which women are most likely to conceive is two to three days before ovulation. This is independent of their age.

Fertile window for four age groups. Probability of conception is highest for an act of intercourse occurring two days prior to ovulation. Redrawn from Dunson et al. (2002). Changes with age in the level and duration of fertility in the menstrual cycle. Human Reproduction, 17(5), 1399–1403, and cited in Amy L. Harris & Virginia J. Vitzthum. Darwin's Legacy: An Evolutionary View of Women's Reproductive and Sexual Functioning, The Journal of Sex Research 2013. 50:3-4, 207-246.

The chances of conception on a random day

In a review of the variability in ovarian function, Amy Harris and Virginia Vitzthum from Indiana University note that although it is the case that the fertile window is fairly narrow (about six days, ending within 24 hours after ovulation) “it does not follow that the fertile window occurs during a narrow range of days during the menstrual cycle. To the contrary, because the timing of ovulation during a cycle is quite variable, women have a 10% or greater probability of being in their fertile window on every day from cycle days 6 through 21, and more than 70% of women are in their fertile window before cycle day 10 or after cycle day 17.”

So they plotted the probability of conception on each cycle day then calculated the mean probability of conception (i.e., clinical pregnancy following a single act of unprotected intercourse on a random day. What they found was that the average probability during cycle days 7-14 was 25% higher than that during cycle days 14-21. The average probability during the first two weeks of the cycle was 16% higher than that during the next two weeks. “Furthermore, in that subset of women who reported having irregular cycles, a not uncommon pattern, length and menses duration), the average probability during cycle days 7-14 is less than half of that during cycle days 14 to 21.”

“Among healthy women trying to conceive, nearly all pregnancies can be attributed to intercourse during a six-day period ending on the day of ovulation. ”

— Wilcox A. et al. Timing of sexual intercourse in relation to ovulation. N Engl J Med 1995;333:1517-21.

This is important.

Panel A: The probability of ovulation by cycle day. Normal variation in the length of the follicular phase of the menstrual cycle: effect of chronological age.

Panel B: Daily probability of conception on each cycle day; mean probability of conception during cycle days 7 to 14= 6% and during cycle days 14 to 21 = 4.8%

Panel C: Daily probability of conception on each cycle day for women reporting regular cycles (thick line) and for those reporting irregular cycles (thin line); in latter sample, the average probability of conception during cycle days 7 to 14 is 2.5% and during cycle days 14 to 21 it is 5.8%.

Halakhic Infertility

Sometimes, as woman may be biologically fertile, but unable to conceive because of halakhic considerations. If a woman has a menstrual cycle that is shorter than the average 28 days (and about 20% of women have just that), or if a woman bleeds for more than 5 days (resulting in a longer Niddah time, in which the couple may not have intercourse) then  - and pay attention to this - then ovulation takes place during the Niddah time. And if that happens, as we noted above, then conception is all but impossible. This might be called halakhic infertility, and it is more common than you might have thought.    

In a study of the prevalence of halakhic infertility in a population of ultra-orthodox Jews seeking help from a fertility clinic, a group from Hadassah Hospital in Jerusalem studied 45 infertile women.  They found that precoital ovulation was prevalent in one-fifth (21%) of the patients.  "Since not obeying the halachic code of conduct is non-negotiable, and in view of the void of halachic solutions, most couples (68%) seek medical advice and treatment."  Fortunately such treatment is available: taking an an oral estrogen can delay ovulation to after the time of mikveh, and allow intercourse to take place at a time when conception is more likely.  

“A fifth of infertile couples were diagnosed as suffering from infertility due to a religious rather than biological cause...This significant proportion of infertile couples who suffer from sociocultural infertility mandates special attention, primarily of the Rabbinate [sic] authorities.”

— Haimov-Kochman R. et al. Infertility associated with Precoital Ovulation in Observant Jewish Couples; Prevalence, Treatment, Efficacy, and Side Effects. Israel Medical Association Journal 14 (2011): 100-103.

Back to the Daf - Which Opinion is Correct?

Let's now return to the question with which we opened; which of the following two opinions is correct?

1. A woman only conceives close to her period(אין אשה מתעברת אלה סמוך לווסתה).

2. A woman only conceives close to her immersion in a mikvah (אין אשה מתעברת אלה סמוך לטבילתה).

The first opinion is most certainly not supported by modern medicine. The second opinion is often likely to be true, but - and this is a BIG BUT - only for women for whom both the menstrual cycle is not short and menstrual bleeding is not long. For a sizable number of women, conception is no longer possible when they are ready to go to the mikveh.

It is a remarkable fact (and one I have never seen addressed or even acknowledged) that orthodox Jewish practice has evolved to permit intercourse only in that part of the menstrual cycle which has a lower chance of conception. As a result, orthodox Jews have become in this respect, halachically subfertile. Fortunately that doesn’t seem to have made much of a dent in their rates of reproduction. “Being Orthodox” wrote Michelle Shain of the Center for Modern Jewish Studies at Brandeis, '“ increases the odds of having any births by a factor of 7.18 and, among women who have given birth, increases the expected number of births by a factor of 6.14.” Remarkably, this is in spite of, and not because of, the laws of ritual impurity that are a foundation of Jewish practice.

Mean expected number of births by age, education and Orthodoxy. From Michelle Shain, Understanding the Demographic Challenge: Education, Orthodoxy and the Fertility of American Jews. Contemporary Jewry 2019. 39: 273.

“Consultation with a Rabbinate [sic] authority was reported by 64% of women, but no halachic solution was provided to any of the applicants. ”

— Haimov-Kochman R. et al. Infertility associated with Precoital Ovulation in Observant Jewish Couples; Prevalence, Treatment, Efficacy, and Side Effects. Israel Medical Association Journal 14 (2011): 101.

Niddah 30b ~ Talmudic Embryology

נדה ל, ב

דרש רבי שמלאי למה הולד דומה במעי אמו לפנקס שמקופל ומונח ידיו על שתי צדעיו שתי אציליו על ב' ארכובותיו וב' עקביו על ב' עגבותיו וראשו מונח לו בין ברכיו ופיו סתום וטבורו פתוח ואוכל ממה שאמו אוכלת ושותה ממה שאמו שותה

Leonardo Da Vinci. Studies of the Fetus in the Womb. Drawn between 1510-1513.

R. Simlai delivered the following discourse: What does an embryo resemble when it is in the bowels of its mother? Folded writing tablets. Its hands rest on its two temples, its two elbows on its two legs and its two heels against its buttocks. Its head lies between its knees, its mouth is closed and its navel is open, and it eats what its mother eats and drinks what its mother drinks...

Talmudic embryology reflected the prevailing Greek theories of the times. But those theories developed without the benefit of microscopes and the other tools later available to scientists. Despite this, sometimes the rabbis of the Talmud were spot on with their embryology. Today’s statement of Rav Simlai is a good example. (He lived in 3rd century CE, and is the rabbi who brought you the famous count of 613 commandments.) It is a perfect description of a growing fetus, written as if Rav Simlai was looking at Leonardo Da Vinci’s famous sketch. But his was not the only talmudic description of a how a fetus grows, so let’s look at some others.

Will the real Abba Shaul please stand up?

On page 25a of Niddah Abba Shaul declared that the fetus grows from its head:

נדה כה, א

אבא שאול אומר תחלת ברייתו מראשו

Abba Shaul says: The beginning of the formation of the embryo is from its head

But elsewhere Abba Shaul has a different theory:

סוטה מה, ב

מהיכן הולד נוצר מראשו וכן הוא אומר ממעי אמי אתה גוזי ואומר גזי נזרך והשליכי וגו' אבא שאול אומר מטיבורו ומשלח שרשו אילך ואילך

From where is the fetus formed? From its head, as the verse says (Ps.71:6): "From my mother's womb you pulled me out (gozi)". And it says later (Jeremiah 7:29) "Pull out (gozi) your hair and throw it away.." Abba Shaul says that the fetus is created from its navel, and from there it sends out roots in all directions.

The contradiction between these two statements was noted by the great French medieval commentator Yakov ben Meir, known as Rabbenu Tam (d. 1174). He suggested that there is an error in the text before us: In Niddah, it should not read “from its head (מראשו), but “like a locust” (כרשון). Indeed this is the reading found in the important medieval dictionary Sefer HaAruch and echoed centuries later in Marcus Jastrow’s dictionary.

תוספות נדה כה,א, ד’ה תחלת ברייתו מראשו

תימה דבפ' בתרא דסוטה (דף מה:) קסבר אבא שאול תחלת ברייתו מטיבורו ומשלח שרשיו אילך ואילך ונראה לר"ת דגרס כרשון וכן פר"ח ובתוספתא פירש כעין חגב דסלעם מתרגמינן רשון וכן משמע דמיירי בשיעור האברים

Rabbenu Tam’s explanation makes a great deal of sense and leaves Abba Shaul with only one opinion: the fetus develops from the navel. This is not exactly what actually occurs, but to the naked eye it is not too far from it. Interestingly, Maimonides declined to take a position on the matter, and wrote simply that “at the beginning, the body of a person is the size of a lentil…”(תְּחִלַּת בְּרִיָּתוֹ שֶׁל אָדָם גּוּפוֹ כַּעֲדָשָׁה).

“The Talmudic Sages,being true polyhistors, took into account experimental biology as well as popular beliefs.”

— Kottek S. Embryology in talmudic and Midrashic Literature. Journal of the History of Biology 1981. 14 (2): 299-315.

Embryonic Development in Antiquity

In 1934 the British historian and embryologist Joseph Needham published A History of Embryology, in which he traced theories of embryonic development from from antiquity to modern times. In this fascinating book we learn that Hippocrates (c. 460-370 BCE) believed the fetus was formed by extracting breath from its mother, and that a series of small fires within the uterus gave rise to the bones and other organs of the embryo. According to Needham, Aristotle (384-322 BCE) understood that the role of the umbilicus was to nourish the fetus. The vessels of the umbilicus join onto the uterus like the root of a plant and through the cord the fetus receives its nourishment. Elsewhere, Aristotle claimed (contra Abba Shaul) that head of the fetus forms first. Galen (c. 129-216 CE) also used the analogy of the umbilicus serving like the root of a plant. According to him the embryo grew from menstrual blood, and then from the blood that nourished it through the umbilical cord.

What Actually Happens -not from THE head or from the navel

Development of the Umbilical cord. A: The posterior body wall is established. B: the vitelline duct form as the cells form a head and tail end, fold inwards on their lateral sides. C: The umbilical cord forms as the yolk sac and vitelline duct fuse. From O'Donnell K. Glick P, Caty M. Pediatric Umbilical Problems. Pediatric Clinics of North America. 1988 24 (1) 792.

At its earliest stage the embryo consists of a sheet of cells, an amniotic cavity and a yolk sac. The sheet of cells develops a head (cranial) and bottom (caudal) end, and grows around most of the yolk sac. This enclosed yolk sac then grows into the gut of the embryo.  The part of the yolk sac that is not surrounded by the embryo is still connected to it by a thin tube called the vitelline duct.  This duct then fuses with the contained yolk sac, and forms a larger bundle of vessels we call the umbilical cord. This occurs between the 4th-8th week of gestation (calculated from the first day of the last menstrual cycle).  

It is clear then, that the embryo does not grow from the head or from umbilical cord.  As you can see from the diagram, the head develops from the early cells of the embryo as it takes on a cranial-caudal polarity, sometime around 3-4 weeks gestation, when the embryo is about 3mm in length. Neither does the embryo grow from the umbilical cord, as Abba Shaul claimed. In fact it is the umbilical cord that grows out from the early embryo, and not the other way around.

However well understood the process of fetal development may now be, pregnancy remains a time that is often fraught with uncertainty and insecurity. The rabbis of the Talmud articulated these fears with a prayer, that reminds us of the fragility of human development and the relief when it all goes well.

ברכות ס,א

שלשה ימים הראשונים יבקש אדם רחמים שלא יסריח משלשה ועד ארבעים יבקש רחמים שיהא זכר מארבעים יום ועד שלשה חדשים יבקש רחמים שלא יהא סנדל משלשה חדשים ועד ששה יבקש רחמים שלא יהא נפל מששה ועד תשעה יבקש רחמים שיצא בשלום

During the first three days after intercourse, one should pray that the seed not putrefy, [that it will fertilize the egg and develop into a fetus].

From the third day until the fortieth, one should pray that it will be male.

From the fortieth day until three months, one should pray that it will not be deformed, in the shape of a flat fish,

From the third month until the sixth, one should pray that it will not be stillborn.

And from the sixth month until the ninth, one should pray that it will be emerge safely.

---

Next time on Talmudology: When Is a woman most fertile?

Niddah 28a ~ Gender Determination

In the time of the Talmud and for centuries beyond, it was very important for a couple to produce male children. To this end, some rabbis suggested a technique to ensure that a boy was produced. We first read about it a couple of days ago, and here it is described in today’s page of Talmud:

נדה כח, א

וא"ר יצחק אשה מזרעת תחלה יולדת זכר איש מזריע תחלה יולדת נקבה

Rabbi Yitzchak said that if the woman emits seed first she gives birth to a male, and if the man emits seed first she gives birth to a female.

Today we will explore the topic of gender determination in the Talmud.

How to conceive a boy or a girl

In this tractate the statement about “emitting seed first” comes up several times, and in the name of a few different rabbis. And, as if emphasize its importance, the Talmud offers no fewer than four different supporting proofs for the principal. Here is the first, in the name of Rav Ami:

נדה לא, א

אמר רבי יצחק אמר רבי אמי אשה מזרעת תחילה יולדת זכר איש מזריע תחילה יולדת נקבה שנאמר (ויקרא יג, כט) אשה כי תזריע וילדה זכר 

Rabbi Yitzchak says that Rabbi Ami says:The sex of a fetus is determined at the moment of conception. If the woman emits seed first, she gives birth to a male, and if the man emits seed first, she gives birth to a female, as it is stated: “If a woman bears seed and gives birth to a male”(Leviticus 12:2). 

The suggestion from the verse is that “if a woman bears seed” first, then she will “give birth to a male.” A second proof text from the Torah is provided by Rabbi Tzadok, this time from the story of our matriarch Leah.

תנו רבנן בראשונה היו אומרים אשה מזרעת תחילה יולדת זכר איש מזריע תחלה יולדת נקבה ולא פירשו חכמים את הדבר עד שבא רבי צדוק ופירשו (בראשית מו, טו) אלה בני לאה אשר ילדה ליעקב בפדן ארם ואת דינה בתו תלה הזכרים בנקבות ונקבות בזכרים 

The Sages taught: At first, people would say that if the woman emits seed first she gives birth to a male, and if the man emits seed first, she gives birth to a female. But the Sages did not explain from which verse this matter is derived, until Rabbi Tzadok came and explained that it is derived from the following verse: “These are the sons of Leah, whom she bore to Jacob in Paddan Aram, with his daughter Dinah”(Genesis 46:15). From the fact that the verse attributes the males to the females, as the males are called: “The sons of Leah,” and it attributes the females to the males, in that Dinah is called: “His daughter,” it is derived that if the woman emits seed first she gives birth to a male, whereas if the man emits seed first, she bears a female.

בנדה לא ,א–ב

The Talmud brings a third proof text, this one from the Book of Chronicles:

ויהיו בני אולם אנשים גבורי חיל דורכי קשת ומרבים בנים ובני בנים וכי בידו של אדם להרבות בנים ובני בנים אלא מתוך שמשהין עצמן בבטן כדי שיזריעו נשותיהן תחלה שיהו בניהם זכרים מעלה עליהן הכתוב כאילו הם מרבים בנים ובני בנים והיינו דאמר רב קטינא יכולני לעשות כל בני זכרים 

“And the sons of Ulam were mighty men of valor, archers, and had many sons and sons’ sons”(I Chronicles 8:40). Is it in a person’s power to have many sons and sons’ sons? Rather, because they delay while lying on wives’ abdomen, initially refraining from emitting semen so that their wives will emit seed first, in order that their children will be male, the verse ascribes them credit as though they have many sons and sons’ sons. And this statement is the same as that which Rav Ketina said: I could have made all of my children males,by refraining from emitting seed until my wife emitted seed first. 

And finally, the fourth proof text. A later passage in this tractate (Niddah 70b-71a) cites a number of questions that the sages of Alexandria asked of Rabbi Yehoshua. One of them was how can a man ensure he has male children? Rabbi Yehoshua told them the man should do two things: marry a woman who is fit for him, and act modestly during sexual intercourse. Hold on, the sages of Alexandria replied. Many men have done that, and it didn’t help! Rabbi Yehoshua then qualified his answer, and explained that in addition to marrying an appropriate woman and being modest, a man needs to pray for a son. Rabbi Yehoshua then cited a proof text from Psalms (127:3):

הנה נחלת ה' בנים שכר פרי הבטן

Behold, children are a heritage of the Lord; the fruit of the womb is a reward

So far so good. To have male children a man needs to marry an appropriate wife, act modestly when he is intimate with her, and pray. But now the Talmud asks a question based on the proof text. What is the act for which the reward are children?

א"ר חמא ברבי חנינא בשכר שמשהין עצמן בבטן כדי שתזריע אשתו תחילה נותן לו הקב"ה שכר פרי הבטן

Rabbi Chama, son of Rabbi Chanina, says: In reward for men withholding their semen in their belly in order to allow their wives to emit seed first, the Holy One, Blessed be He, gives him the reward of the fruit of the womb, [that is, sons].

These are the four different proof texts from the Bible to support the claim that if a woman emits her seed first, she will give birth to a boy. Of course now we need to determine what, precisely, is meant by the phrase “if the woman emits seed first” (מזרעת תחילה).

Understanding THE PHRASE

(i) Ovulation

Perhaps it could refer to ovulation. This makes sense to us since we understand that fertilization requires two “seeds,” the egg, and sperm. But this would not have made sense to the rabbis of the Talmud. They, like everyone else at the time (and indeed until the beginning of the seventeenth century) had no concept of mammalian ovulation. In fact it was the blood that was lost at menstruation that was believed to be the mother’s contribution to her child’s formation, and not any eggs she may produce.

A classic example of this lack of understanding of ovulation is found in the early medieval commentary of Moses ben Nachman, known as Ramban (1194–1270) to Leviticus 12:2. Here is the key bit:

כי האשה אע"פ שיש לה ביצים כביצי זכר או שלא יעשה בהן זרע כלל או שאין הזרע ההוא נקפא ולא עושה דבר בעובר

For even though a woman has ovaries like the testes of a man, either they do not produce eggs at all, or else the egg jells and contributes nothing to the fetus.

(ii) Orgasm

The other possibility is that “emitting seed first” refers to orgasm. If you want to have a boy, the rabbis said, the husband should allow his wife to have an orgasm before himself. This interpretation is favored by the historian of all things medical and talmudic, Fred Rosner. Here is what he wrote in Medicine in the Bible and The Talmud (Ktav Publishing and Yeshiva University Press 1977, p175):

It seems obvious…that the meaning must be orgasm rather than ovulation, for otherwise it would not make sense to speak of the men restraining themselves during intercourse in order to allow their wives to “emit seed” first.

Theories of sex determination in Antiquity

In a fascinating paper in the Journal for the Study of Judaism, the scholar Pieter van Horst wrote “it is certain that ancient Greek concepts of embryogenesis influenced Jewish theories about the coming-into-being of a foetus.” So let’s look at some of those theories.

Aristotle (384–322 BCE) recorded the belief (with which he did not agree) that male offspring come from the right side of the male and females from the left side; an embryo that develops in the “right side” of the uterus (whatever that means) becomes male while that which develops in the left side becomes female. Aristotle himself believed that the mother’s contribution to the fetus was menstrual blood, and it had the same origin as male semen, although it was not as developed.

Another Greek, Empedocles (c. 494-434 BCE) thought that “heat” (whatever that means) gave rise to males and cold to females. But the view in the Talmud about editing seed first can be traced further back to another Greek, Democritus of Abdera (c. 460 - c. 370 BCE). Democritus believed that the gender depended on the parent whose semen predominated, “not the whole of the semen, but that which has come from the part by which male and female differ from one another.”

By the time we get to Galen, the Greek physician of the second century, there was an acknowledgement that the mother contributed her own seed, but, as van Horst notes the thought was that“…female sperm is by far less perfect, thinner, and colder than male sperm; it serves only as food for the male semen in its development into an embryo.

“The material surveyed so far covers the period of roughly 500 B.C.E. to 200 C.E. It has shown us that throughout this period a theory about female semen had its place side by side with a theory that denied females a contribution to embryogenesis. ”

— Pieter W. van Horst. Bitenosh's Orgasm. Journal for the Study of Judaism 2012. 43: 613-628.

A new understanding of a Dead Sea Scroll

It is with this background that van Hort explains an enigmatic passage in one of the Dead Sea Scrolls (1QapGen2:9-15), known as the Genesis Apocryphon. It is one of the original Dead Sea Scrolls discovered by Bedouin shepherds in 1946 and now held at The Shrine of the Book in Jerusalem.The scroll recounts a discussion between Noah and his father Lemech, who was worried that Noah was not really his own progeny. “I thought in my heart” says Lemech, “that the conception was the work of the Watchers, and the pregnancy of the Holy Ones, and it belonged to the Nephilim.” He suspects that his wife Bitenosh has committed adultery.

Then Bitenosh, my wife, spoke to me very harshly... (9) and said: 'Oh my brother and lord, remember my sexual pleasure!... (10) in the heat of intercourse, and the gasping of my breath in my breast.'" …(14) Remember my sexual pleasure!... (15) that this seed comes from you, that this pregnancy comes from you…

How, asks van Horst, could Bitenosh think that a reference to the pleasure she experienced when being intimate with Lamech would allay his suspicion? And here is his fascinating solution:

That could only be a convincing argument if that pleasure entailed the conception of their child at the moment the two of them (and no one else) were together. Since the author implies that Bitenosh's argument did convince Lamech, he must have meant her reference to her pleasure to be a conclusive argument. So "pleasure" must here definitely be something much more specific than just the fact that Bitenosh had a pleasant time with Lamech when they begot Noab. That is to say, most probably Bitenosh here refers to her orgasm on that occasion. The fact that not only Lamech but also Bitenosh had an orgasm at that moment is taken as a proof that it is the two of them, together who begot the child. That can only be the case if the female orgasm is here regarded as the event during which she emitted her own seed into her womb where it mingled with Lamech's seed so as to form the beginning embryo. It is only a double-seed theory that can explain why Bitenosh here takes recourse to an appeal to her moment suprême (to which Lamech was witness!) as a cogent argument…

It is fascinating to see how an originally Greek scientific concept here serves to allay the anxious suspicions of a biblical hero.

Yes. It is.

It wasn’t until the invention of the microscope and the work of Antonie van Leeuwenhoek (1632-1723) and Reinier de Graaf (1641-1673), that we began to understand what was really going on. The former described seeing sperm in semen, and the latter dissected pregnant rabbits and described the development of the egg in the ovary. (Fun fact: in his honor, the structure within which the egg matures is known to this day as a Graafian follicle.)

Other ways to have a baby boy

The scholar Moses Gastner who died in 1939 was a lifelong collector of Hebrew manuscripts. These later became part of the collectionso of both the Rylands Library in Manchester and the British Library in London. Gastner also translated the siddur, wrote a history of the Bible, and led the Spanish and Portuguese Congregation in London. Among his many works was a little-known entry (“Birth, Jewish”) in the two-volume Encyclopædia of Religion and Ethics published in New York in 1908. In the entry Gastner included material from his the vast collection of medical and magical manuscripts. Here is one, which Gastner does not date: 

If a woman is anxious to get sons, she must ask a shepherd to get the after-birth of a cow, dry it, and pound it, and drink the powder in wine.

If dried cow after-birth did not suit your tastes, there was this: 

Make a decoration of bear’s or wolf’s meat as much as a bean. If the animal is male the child will be male, and if it is female, the woman will give birth to a daughter.

The Talmud (Niddah 31b) suggested another, perhaps more palatable method to guarantee a baby boy:

אמר רבא הרוצה לעשות כל בניו זכרים יבעול וישנה 

Rava said: One who wishes to make all of his children males should engage in intercourse with his wife and repeat the act.

It’s not a secret any more

At the conclusion of his article on sex determination in the Talmud, Rosner wrote that the Talmud 

emphatically states that if a woman emits her semen first, she will bear a male, and if the man emits his semen first, she will bear a female. We have yet to understand what the Talmud means. The secret of sex predetermination remains hidden.

But this is not correct. We certainly do understand what the Talmud meant, where that meaning came from and what became of it. What once was certainly a mystery (but not a secret) is now well understood. The gender of offspring is determined by chromosomes, and nothing else. 

What actually determines the gender of a fetus

A human egg or sperm each contain 23 chromosomes. All eggs carry an X chromosome; each sperm carries an X or a Y chromosome. If a sperm with an X chromosome fertilizes the egg, the fetus grows into an XX female. If a sperm with an Y chromosome fertilizes the egg, the fetus grows into an XY male. That’s it. Simple.