Niddah 38a ~ How Long Does A Pregnancy Last?

If you have ever stayed up all the way to the end of a Pesach Seder, you will have sung the following:

תשעה מי יודע
תשעה אני יודע
תשעה ירחי לידה

Who knows Nine?

I know nine.

Nine are the months of a Pregnancy.

Well I have some news - it ain’t necessarily so. It all begins on today’s page of Talmud:

נדה לח,א

 אמר שמואל אין אשה מתעברת ויולדת אלא למאתים ושבעים ואחד יום או למאתים ושבעים ושנים יום או למאתים ושבעים ושלשה 

Shmuel says that a woman becomes pregnant and gives birth only after 271 days, which is a full nine months, or after 272 days or after 273 days.

As Rashi explains, nine (thirty day) months is 270 days following intercourse. On day 271, the start of the tenth month of pregnancy, the baby is born. Sometimes though, the egg is not fertilized for 24 or even 48 hours, in which case birth happens on day 272 or 273 after intercourse.

Today’s question is, was Shmuel, the famous second century Babylonian physician-rabbi (and head of the yeshiva of Negardea) actually correct?

“
The length of human gestation varies considerably among healthy pregnancies, even when onset of pregnancy is measured by an accurate marker of ovulation. This variability is greater than suggested by the clinical assignment of a single ‘due date’.”

— Jukic A.M. et al. Length of human pregnancy and contributors to its natural variation Human Reproduction 2013. 28 (10): 2848–2855

The length of gestation calculated by the time from the last menstrual period

Generally speaking, studies that examined the length of gestation have estimated gestational age either by the mother’s last menstrual period (LMP) or by ultrasound, both of which are imperfect measures. Based on the first date of the LMP, the end of gestation is 280 days later. But that is not the length of time to which Shmuel referred. He was very precise, and calculated the duration (or received a tradition that was) based on the number of days post conception, Shmuel assumed conception would be on the date of intercourse, or no no more than two days later.

Estimated Due Date (EDD) Calculator. Based on the standard 280 days after the first day of the mother’s last menstrual period.

The actual median length of gestation

In 2013 a study funded by the National Institutes of Health measured things a little differently. It calculated the length of gestation beginning at ovulation or conception in 125 naturally conceived, singleton live births, and determined the exact date of ovulation and implantation by measuring urinary hormone measurements. What they found was very close to Shmuel’s length of gestation. The median time (which is not the average time) from ovulation to birth was 38 weeks and 2 days, or 268 days. That’s a difference of only two days! That’s strong work from Shmuel, who figured it out without the resources of the National Institutes of Health (annual budget, about $32 billion).

Smoothed distribution of length of gestation (accounting for medical interventions that shortened gestation) derived from 125 singleton live births. Solid line: ovulation-based length of gestation. Dashed line: LMP-based length of gestation. From Jukic A.M. et al. Length of human pregnancy and contributors to its natural variation Human Reproduction 2013. 28 (10): 2848–2855.

There is an important caveat, however. The study found that the gestational length varied by 37 days (even after excluding preterm births or pregnancies with medical conditions). This means that the length of human pregnancies can vary naturally by as much as five weeks, and - this is important- that much of this reflects natural variation.

But other factors can influence the length of a pregnancy. For example, older women deliver later on average, with each year of age adding roughly one day to their pregnancy. And women who had themselves been heavier at their own births had longer gestations, with each 100g in the mother's own birth weight corresponding roughly to a one-day longer pregnancy.

The practice of early pious ones

All of which leads us to question the practice of the early pious ones, as they are called by the Talmud. Today’s page of Talmud describes how this group was so convinced by the tradition that gestation was exactly 270 days that they would only have intercourse on a Wednesday, Thursday or Friday. They did this to avoid the risk of the baby being delivered on the Shabbat, and any desecration of it, albeit legally permitted, that might occur to care for the infant or its mother.

Their thinking went like this: 270 days is 38 complete weeks and four days. This meant that delivery would occur four days later in the week than had conception. So if the baby was conceived on a Wednesday, it would be delivered on a Sunday, or a Monday (if fertilization was delayed by 24 hours) or a Tuesday (if fertilization was delayed by 48 hours.) Similarly, a baby conceived on a Thursday could only be born on a Monday, Tuesday or a Wednesday. A baby conceived on a Friday could only be born on a Tuesday, Wednesday or a Thursday. But if the baby was conceived on a Sunday, Monday or Tuesday, they ran the risk of it being born on a Shabbat.

דתניא חסידים הראשונים לא היו משמשין מטותיהן אלא… מרביעי ואילך

As we know, nature does not always cooperate; gestation may on average be about 270 days after conception, but that is an average (or more precisely a median). Some pregnancies are naturally shorter and some longer. Dr Jukic, the lead author of the paper that recalculated the length of human gestation noted that “natural variability may be greater than we have previously thought.” And that is certainly the case for Shmuel and the early pious ones, who calculated the length of gestation with great precision, but alas, not great accuracy.

Niddah 36 ~ Fever

נדה לו, ב

חלש רב אסי עיילוה בחמימי אפקוה מקרירי עיילוה בקרירי אפקוה מחמימי נח נפשיה דרב אסי

Rav Assi became ill. When he had a fever his chills were relieved, and when he had chills his fever ended. Eventually, Rav Assi died.

We have previously discussed fevers in the Talmud, when we read the tractate Nedarim.

נדרים  מא, א–ב

אמר רבא האי אישתא אי לאו דפרוונקא דמלאכא דמותא מעלי כחיזרא לדיקלי חד לתלתין יומין

Rava said about a fever: "Were it not for the fact that it is an agent of the Angel of Death, it would be beneficial for a person as a prickly foliage is for palm trees, if it is experienced once every thirty days...(Nedarim 41a-b).

As an emergency physician I've treated hundreds and hundreds of patients who came to the ER with a fever.  In fact fever is the third most common reason in the US for which people visit the ER - accounting for over 5 million visits each year. At virtually every visit they'd be given a medicine to reduce their fever, as if by doing so we were achieving something medically important. But here we read that according to Rava, fever is actually beneficial to a person (at least when it does not kill you as it did poor Rav Assi).  Was Rava, a Babylonian sage who died around the year 352 CE, correct when he claimed that a fever might be good for you? He was, as it turns out. Here's why.

Fever 101

Here are some basic things to know about fever. First, it is usually defined as a core temperature in humans above 38.3 C, or 101 F.  Second, there are lots of reasons why people get a fever, of which bacterial and viral infections are the most common, but not the only causes.  Third, and this is really important, not all fevers mean the same thing in terms of their seriousness.  Fever in a baby less than a month old requires an urgent and extensive evaluation. The same fever in a healthy toddler does not.  Fever in a healthy teenager is not the same as fever in an elderly patient on chemotherapy.  Finally, fever is not caused by the infection, at least not in the way you might think. It is the body's response to that infection that produces a fever.  Here's how.

The Biochemical Pathway to Fever

When bacteria infect the body, their foreign structure is recognized by white cells in the blood called macrophages. These macrophages then release a prostaglandin E2, interleukin-1, interleukin-6, and tumor necrosis factor. These act on a region deep in the brain called the hypothalamus, which acts as a thermostat for the body. Under the influence of interleukin-1 the hypothalamus releases a hormone called cyclooxygenase 2 (COX-2) which resets the body's thermostat, causing the temperature of the body to rise by a few degrees.  

How a fever is caused by a bacterial infection. From Evans, Repasky and Fisher. Fever and the thermal regulation of immunity: the immune system feels the heat. Nature Reviews Immunology June 2015: 15: 337.

It's not just people who get fevers. Dogs and cats do too, as do mice (and all mammals), reptiles, and even goldfish. Why would so many animals respond to an infection by developing a fever?

The Benefits of Fever

The reason is simple. The immune system fights infections better when the body is hotter. The way it does this is now well-understood but very complicated; here are just the highlights. 

Under what immunologists call "thermal stress" (and the rest of us call "a fever",) neutrophils, the white cells that are needed to fight infection, are released in greater numbers from the bone marrow.  These neutrophils also do a better job of fighting bacteria at the site of the infection when the body is warmer.  Fever also improves the killing ability of another group of blood cells called natural killer cells, and it increases the ability of the macrophages to ingest and destroy the invading bacteria. As last month's excellent review of fever and the thermal regulation of immunity in Nature Reviews concluded, "[t]he picture that emerges is one in which febrile temperatures serve as a systemic alert system that broadly promotes immune surveillance during challenge by invading pathogens."  

So your body does a better job of fighting bacteria when it is hotter.  Why then, do doctors give medicines that reduce a fever?  Good question. The truth is, they really shouldn't.

Don't Reach for That Tylenol/Paracetomol/AcAmol 

If you are the parent of a child with a fever, you are likely to give your sick offspring a medicine that interferes with the immune system, like Tylenol if you are in the US, Paracetamol if you are in the UK or South Africa, or Acamol in Israel (though they are different words for the same medicine.)  But if, as we have seen, the body does a better job of fighting infection when it is a few degrees hotter, might reducing the fever lead to a worse outcome for the child?

This question was recently examined by a group from McMaster University in Canada. They looked at the side effects of reducing a fever in those who are sick from a population level . What happens in a large group of people when some of them - infected with, say, influenza - take medicines to reduce their fever? The answer is that more of them transmit the virus and so more of them fall ill.  On a population level the effect is rather drastic:

Putting together our estimates of the treatment probability p and the individual transmission enhancement factor fi ...we conclude that the current practice of frequently treating fevers with antipyretic medication has the population-level effect of enhancing the transmission of influenza by at least 1% (95% CI: 0.04–3%)...This estimate does not take into account the known effect that the infectious period of influenza is also increased by antipyresis, nor does it take into account the potentially large effect of increasing the rate of contact among infectious and susceptible individuals because antipyresis makes infectious individuals feel better...To put our lower bound...into perspective, consider that approximately 41,400 ...deaths per year are attributed to seasonal influenza epidemics in the United States (and an order of magnitude more worldwide). Taken at face value, our results indicate, for example, that...at least 700 deaths per year ... could be prevented in the US alone by avoiding antipyretic medication for the treatment of influenza...

“In the absence of meaningful evidence for the beneficial effects of fever reduction, the commonplace reduction of fever in critically ill patients must be called into question.”

— Ryan and Levy. Clinical Review: Fever in intensive care patients. Critical Care 2003, 7:224.

The Canadian investigators concluded that "...the use of antipyretics can have subtle and potentially important negative effects at the population level. Any medical intervention that aims to relieve the symptoms of an infectious disease in an individual should also be evaluated in light of potentially harmful effects at the population level..." And it's not just populations that can suffer; individual patients are at risk too. In a 2011 paper looking at the treatment of fever in very ill patients with sepsis in the ICU,  a French team looked at the beneficial and detrimental effects of fever, and concluded that "...the widespread use of antipyretic methods in ICU patients is not supported by clinical data and fever control may be harmful, particularly when an infectious disease is progressing..."

From Lainey Y. et al. Clinical review: Fever in septic ICU patients - friend or foe? Critical Care 2011:15:222

The Death of Rav Assi - from Fever

So Rava's teaching found on Nedarim 41b is scientifically accurate.  Fever is indeed beneficial for the body, though it is a sign that something bad is going on.  Which is what happened on today’s page of Talmud when another Babylonian Amora, Rav Assi, died from a fever accompanied with chills - the classic description of sepsis (and a lot else besides, too). It is interesting to note that according to the Soncino translation of today’s passage of Talmud, Rav Assi's attendants tried to reduce his fever.  Perhaps they not aware of the tradition that Rava - who was born two generations later - would later teach.

R. Assi fell ill and they had to put him in hot [blankets] to relieve him from chills, and in cold [compresses] to relieve him from heat,[but] his soul departed to its eternal rest.

Fever may be beneficial, but the underlying infection of which it is a sign never is.  Which is why Rava's teaching was not accepted by by Rav Nachman bar Yitzchak who retorted (Nedaraim 42,): לא היא ולא תירייקה:  "Give me neither fever, nor its antidote!" Rav Assi probably thought the same thing.

[Mostly a repost from here.]

Niddah 35b ~ The Zov, and Gonorrhea

נדה לה, ב

אמר רב הונא זוב דומה למי בצק של שעורים זוב בא מבשר המת שכבת זרע בא מבשר החי זוב דיהה ודומה ללובן ביצה המוזרת שכבת זרע קשורה ודומה ללובן ביצה שאינה מוזרת

Rav Huna says: The discharge of ziva is similar to water of barley dough. Whereas the discharge of ziva comes from dead flesh, i.e., when one’s penis is flaccid, semen comes from living flesh, when one’s penis is erect. Moreover, the discharge of ziva is runny, and is similar in appearance to the white of a unfertilized egg. By contrast, semen is viscous, and it is similar in appearance to the white of an egg that is not unfertilized, i.e., a fertilized egg.

The Zov in The Torah...

In Leviticus chapter 15 the laws of the זב – Zov - a man who experiences a discharge from his penis - are outlined.

ויקרא טו, ב–ג

אִישׁ אִישׁ כִּי יִהְיֶה זָב מִבְּשָׂרוֹ זוֹבוֹ טָמֵא הוּא. וזֹאת תִּהְיֶה טֻמְאָתוֹ בְּזוֹבוֹ רָר בְּשָׂרוֹ אֶת־זוֹבוֹ אוֹ־הֶחְתִּים בְּשָׂרוֹ מִזּוֹבוֹ טֻמְאָתוֹ הִוא

When any man has a discharge issuing from his member, he is unclean. The uncleanness from his discharge shall mean the following—whether his member runs with the discharge or is stopped up so that there is no discharge, his uncleanness means this…

If a man experiences this discharge on two days he becomes impure (טמאי), and must undergo a process of spiritual recovery that includes isolation from others and immersion in running water. If he has a third day of penile discharge he is required to bring an offering to the Temple. (The laws differ in their application to a woman who is infected, but the basic idea is the same. To keep it simple, we'll just focus on the male Zov.)

“ אין כל צורך להביא ראיות ומופתים להוכיח, כי במחלה מתדבקת ידועה
Gonorrhoe הכתוב מדבר, במחלה הנקראת אצלינו היום

There is no need to bring any proofs to prove that the verse in the Bible is referring to a well known infection, which today we call Gonorrhoe [sic]...”

— י.ל קצנלסון. התלמוד והכמת הרפואה. הוצאת חיים ברלין תרפ׳ח. 378

...And in the Talmud

The rabbis of the Mishnah thought that if the discharge was due to an external factor, then the person so afflicted did not become a Zov. Here is the list of those external causes of genital discharge, as outlined in Nazir 65b:

נזיר סה, ב

בשבעה דרכים בודקין את הזב עד שלא נזקק לזיבה במאכל ובמשתה במשא ובקפיצה ובחולי ובמראה ובהירהור

A Zov is examined in seven ways…about food and drink [certain foods such as cheese and wine could have caused the discharge], about carrying a load, jumping and illness [strenuous physical activity could also do so], sight and thought [he is asked whether he has been thinking about or looking at women, which could have caused his discharge]…

In modern Hebrew, zivah (זיבה) is the term for gonorrhea, a sexually transmitted disease caused by the bacterial species Neisseria gonorrhoeae.  Preuss, in his famous Biblical and Talmudic Medicine has this to say about the Zov:

“It is clear forthwith that the only illness we know that can be referred to here is gonorrhea” (354).

Abraham Steinberg, in his more recent three volume Encyclopedia of Jewish Medical Ethics, also identifies the disease described in Leviticus as gonorrhea, (though he notes that some rabbis identified the discharge as being sperm, rather than pus. More on that below).  If a Zov is indeed a man suffering from gonorrhea, that would explain “the laws of isolation and impurity in regard to people with flux [=discharge] as being hygienic rules to prevent the spread of the disease” (Vol  II, p452).

More than you wanted to know about gonorrhea

According to the Centers for Disease Control and Prevention, there are about 330,000 new cases of gonorrhea in the US. That makes it the second most common sexually transmitted disease, with first place going to chlamydia- and the two are frequently found together. The World Health Organization estimated a global total of  106 million cases in 2008 (and that’s an increase of 21% compared to 2005).  Gonorrhea is most common in women age 15-19, and infections in women are usually asymptomatic. In contrast, gonorrheal infection in men is nearly always symptomatic, with the most common symptoms being pain on urination (dysuria) and purulent penile discharge. (Think of what comes out of your nose when you get a bad cold. Now think of that coming out of another orifice.)   But gonorrhea is not just a disease of the genital tract. It may involve the eyes, pharynx and anus, and if it is not treated it may (rarely) progress to disseminated disease that includes endocarditis and meningitis. In women, untreated gonorrhea can cause pelvic inflammatory disease and sterility.

While the Zov in Temple times had to remove himself society and hope for an end to the symptoms, in the era of antibiotics things are different. Gonorrhea is generally easy to treat – a single shot of ceftriaxone in the muscle and a swig of oral azithromycin and you are on the mend. The problem is that drug resistant gonorrhea is now emerging worldwide, and consequently some infections are difficult to treat. 

Don't Touch That Chair...

As outlined in the Torah, the Zov imparts ritual impurity to the bed on which he lies and the chair on which he sits. Preuss wrote that “the hygienic value of these regulations… is obvious.” If the disease that is described in the Torah is indeed gonorrhea, well, then we now understand enough to say that the hygienic value of these regulations is, contra Preuss, really not that obvious at all. We now know that you cannot catch gonorrhea from sitting on a chair or lying on a bed that an infected person had touched.  But in fairness, such beliefs were not uncommon even a century age. We’ve had occasion to review the theories prevalent in early twentieth century America about the transmission of gonorrhea. Back then, doctors claimed girls were susceptible to infection from gonorrhea “from everyday nonsexual objects, including their mothers’ hands, bed linens…and toilet seats.” It is hardly surprising, therefore, to read in the Torah, that the Zov contaminates all he touches. But it is not so. You need sexual or oral contact to transmit the disease, (which can also be caught by the innocent new-born baby passing through its mother's infected genital tract).  

Maimonides on the Nature of the Zov

In his Mishneh Torah, Maimonides identified the Zov as suffering from a physical disease – and not a spiritual one [הלכות מחוסרי כפרה 2:1]:

The Zov that is described in the Torah, is a form of semen that results from an infection in the tubes [of the genital tract]. When the discharge of the Zov flows, it does not do forcefully like ejaculate, and there is no pleasure associated with it. Rather it flows passively like dough…

(Maimonides was following the best medicine of his time when he described the discharge as a form of semen. The word gonorrhea is from the Greek roots gone meaning seed and rhein, meaning flow.)

In an era that did not have antibiotics, removing the infected person and isolating him was really all that could be done. Today, we have alternatives: antibiotics to treat the infection, and condoms to prevent its spread.   But we lack the self-reckoning that the infection might encourage. I’ve treated many, many cases of gonorrhea, and every patient encounter was centered on diagnosing and treating the infection. I do not recall any discussions about changing the behavior that allowed infection to take place in the first place. Perhaps I bear responsibility for not having had that conversation, and perhaps I should have followed the example of the biblical text. That text was mistaken in some of the details of how the disease is spread, but accurate in requiring the Zov to leave his social network, and perhaps reflect on the kind of behaviors that led to his infection in the first place.

[Repost from here.]

Niddah 30-31 ~ Talmudic Obstetrics

Let’s go back to some of the Talmud we studied last week in the daf yomi one-page-a-day cycle, and catch up with some topics we didn’t have a chance to cover.

1. Which fetus grows quicker, Male or Female? (The male)

In the Mishnah (30a) there is a dispute between Rabbi Yishmael and the rabbis about the length of time it takes for a fetus to reach a milestone of completion.

רבי ישמעאל אומר יום מ"א תשב לזכר ולנדה יום פ"א תשב לזכר ולנקבה ולנדה שהזכר נגמר למ"א והנקבה לפ"א וחכ"א אחד בריית הזכר ואחד בריית הנקבה זה וזה מ"א

Rabbi Yishmael said…the formation of the male offspring concludes on the forty-first day and the formation of the female offspring concludes on the eighty-first day. And the Rabbis say: both a male and female fetus concludes on the forty-first day.

In one respect, both the rabbis and Rabbi Yishmael were incorrect: the fetus is not fully formed, or fully anything by the forty (ot the forty-first day). Here is what a human embryo looks like at about four weeks (28 days), six weeks (42 days) and seven weeks (49 days). Does one stage look any more “complete” than another?

Human embryo at about 28 days.

Human embryo at about 40 days. It is about 11mm long.

Human embryo at about 46 days. All images are from From Nilsson, Lennart. A Child is Born. Delacorte Press/Seymour Lawrence. 1990.

But in another respect Rabbi Yishmael was certainly correct and the rabbis were wrong: the male and female fetus do grow at different rates. Back in the late 1960s scientists suggested that the greater the antigenic differences between mother and fetus, the greater is the fetal growth rate. In other words an (XY) male fetus grows at a quicker rate than a (XX) female fetus because an XY fetus is more different from its XX mother than is an XX fetus.

It is well known that, on average, boys weigh slightly more than girls at birth. Less known is the fact that when in utero, boys grow at a quicker rate than girls. For example the diameter of the fetal head (called the biparietal diameter) is larger in male fetuses than in the female, and this difference becomes statistically significant at 24 weeks. Head circumference is also larger for males and becomes significantly greater than that of the female fetus at 24 weeks' gestation.

Head circumference (centimeters) as a function of gestational length (weeks) in both male (•) and female (o) fetuses. From Parker A et al. The ultrasound estimation of sex-related variations of intrauterine growth. Am. J. Obstet. Gynecol 1984. 149:665-669.

To conclude: the evidence supports Rabbi Yishmael to the degree that later in utero boys do grow at a slightly quicker rate. However, there is no difference between growth rates before about 24 weeks, and certainly at a forty day cut-off both male and female fetuses are identical. With a generous reading, that supports the opinion of the rabbis.

Very much related to this topic is the story told on the same page of Talmud about Cleopatra and her cruel experiments on young women.

נדה ל, ב

אמרו לו לר' ישמעאל מעשה בקליאופטרא מלכת אלכסנדרוס שנתחייבו שפחותיה הריגה למלכות ובדקן ומצאן זה וזה למ"א אמר להן אני מביא לכם ראייה מן התורה ואתם מביאין לי ראייה מן השוטים 

They said to Rabbi Yishmael: There was an incident involving Cleopatra, Queen of Alexandria. Since her maidservants were sentenced to death by the government, she took advantage of the opportunity and experimented on them to determine the amount of time it takes for an embryo to develop. She had her maidservants engage in intercourse and operated on them following their execution in order to determine the stage at which an embryo is fully formed, and found that both in this case, when the embryo is male, and that case, when it is female, the formation is complete on the forty-first day after conception. Rabbi Yishmael said to them in response: I bring you proof from the Torah, and you bring me proof from the fools?

Not really. A forty day male and a forty female embryo are visually indistinguishable. The reproductive tract begins to develop in the sixth week of the embryonic period, and external genitalia develop during the 8th-14th weeks of gestation. However, external determination of sex is not possible before urogenital modeling is complete, which also occurs between the 8th and 14th weeks. In the hands of an expert ultrasound operator, sonographic determination of fetal sex has been reported as early as 11 weeks’ menstrual age, “but it may be obtained reliably only as early as 12 to 13 weeks.” (The challenge is distinguishing “between a small penis and a prominent clitoris and between minimally edematous labia and a small scrotum filled with spongy connective tissue.” Now you know.)

In the course of a series of challenges to the opinion of Rabbi Yishmael, the Talmud cites the forth century sage Abaye. He suggests that by examining certain of their anatomical characteristics we can determine if two fetuses were a similar age (“אמר אביי בסימניהון שוין”).  He does not define those “characteristics” but Rashi, the eleventh century commentator does.

בסימניהון שוין - נקבה שנמצא ליום פ"א לא היו אבריה ושערה וצפורניה אלא כשיעור של זכר ליום מ"א

Identical characteristics: The limbs, hair, and nails of an 81 day-old female fetus are as developed as those of a 41 day-old male fetus.

There is a problem here. Fingernails only begin to start to develop around day 70 and toenails around day 100. Neither are present at day 40. Hair develops between weeks 7-12. So the claim that either was clearly present in a 40 or 80 day embryo is not possible.

2. How does the uterus grow?(It stretches)

נדה לא, א

תנו רבנן שלשה חדשים הראשונים ולד דר במדור התחתון אמצעיים ולד דר במדור האמצעי אחרונים ולד דר במדור העליון וכיון שהגיע זמנו לצאת מתהפך ויוצא וזהו חבלי אשה 

The Sages taught in a baraita: During the first three months of pregnancy, the fetus resides in the lower compartment of the womb; in the middle three months, the fetus resides in the middle compartment; and during the last three months of pregnancy the fetus resides in the upper compartment. And once its time to emerge arrives, it turns upside down and emerges; and this is what causes labor pains…

Here is what actually happens. The fetus does not occupy different parts of the uterus as it grow. Instead, the uterus itself expands to accommodate the fetus. In a woman who has never been pregnant, the uterus is about 7-8cm long, around the size of a fist. It grows as the fetus develops, reaching up into the abdominal cavity. At 24 weeks’ gestation, the top of the uterus is at the approximate height of the umbilicus, and by the end of pregnancy it may be felt a little below the lower end of the breast bone.

In contrast, the Talmudic description of the baby turning is correct. The baby floats in a heads-up position until the very last couple of weeks of the pregnancy, when it does a 180 degree flip. About 4% of babies refuse to undertake these gymnastics, and remain heads-up, in what is called a breech presentation.

3. who causes worse labor pains, boys or girls?(They are equal OFFENDERS)

נדה לא, א

היינו דתנן חבלי של נקבה מרובין משל זכר 

 The labor pains experienced by a woman who gives birth to a female are greater than those experienced by a woman who gives birth to a male…

…מאי שנא חבלי נקבה מרובין משל זכר זה בא כדרך תשמישו וזה בא כדרך תשמישו זו הופכת פניה וזה אין הופך פניו 

…The Gemara asks: What is different about the labor pains experienced by a woman who gives birth to a female, that they are greater than those experienced by a woman who gives birth to a male?The Gemara answers: This one, a male fetus, emerges in the manner in which it engages in intercourse. Just as a male engages in intercourse facing downward, so too, it is born while facing down. And that one, a female fetus, emerges in the manner in which it engages in intercourse,i.e., facing upward. Consequently, that one, a female fetus, turns its face around before it is born, but this one, a male fetus, does not turn its face around before it is born.

It wasn’t just the rabbis of the Talmud who believed girls caused their mothers more pain during childbirth. Here is Aristotle (d. 322 BCE), in his Historia Animalum (Book 7 Chapter 4):

As a general rule women who are pregnant of a male child escape comparatively easily and retain a comparatively healthy look, but it is otherwise with those whose infant is female; for these latter look as a rule paler and suffer more pain…nevertheless the rule is subject to exceptions.

LEFT: Face down (OA) presentation. Right: Face up (OP) presentation. From here.

When a baby is born face down, that is to day facing the mother’s back, it is said to be in the occipital anterior (OA) position. This is the most common presentation. When the baby is born face up, that is to say facing the mother’s front, it is said to be in the occipital posterior (OP) position. That presentation is less common. In 2005 a group from the Departments of Obstetrics and Gynecology at the Brigham and Women’s Hospital and Boston Medical Center conducted a prospective cohort study of 1,562 women to evaluate changes in baby’s position during labor. They reported that 80% of the babies were delivered OA, 8% were OP and 12% were in the in-between transverse position. Now what about the Talmud’s suggestion that girls are not born face down, or as an obstetrician would say, in the OA position, but rather face up? Take a look for yourself at the results of the study:

Demographic and Pregnancy Characteristics of 1,572 births. From Lieberman E. Davidson K, Lee-Parritz A. Shearer E. Changes in Fetal Position During Labor and Their Association With Epidural Analgesia. Obstetrics & Gynecology 2005. 105 (1): 974-982.

As you can see, boys made up 58% of the face down births and only 49% of the face up births. So although the Talmud’s suggestion that all boys are born face down is not correct, it is certainly the case that slightly more boys than girls are born in this presentation, at least according to this study. However a 2017 Israeli study (which looked at babies with large heads) found that boys made up 51% of the face down births, and 49% of the face up births, which was a statistical wash.

What about pain? If the Talmud is correct, then the face-up (supposedly female) presentation should be more painful than the face-down (supposedly male) one. Is it? Well, no. The Boston study found that mothers face up baby at delivery did not report more painful labors. They had a mean pain score of 4.9 out of 10, compared with 5.2 for other positions - a non statistical difference.

4. Is intercourse during pregnancy harmful?(No)

נדה לא, א

תנו רבנן שלשה חדשים הראשונים תשמיש קשה לאשה וגם קשה לולד אמצעיים קשה לאשה ויפה לולד אחרונים יפה לאשה ויפה לולד שמתוך כך נמצא הולד מלובן ומזורז 

The Sages taught in a baraita: During the first three months of pregnancy, sexual intercourse is difficult and harmful for the woman and is also difficult for the offspring. During the middle three months, intercourse is difficult for the woman but is beneficial for the offspring. During the last three months, sexual intercourse is beneficial for the woman and beneficial for the offspring; as a result of it the offspring is found to be strong and fair skinned.

תנא המשמש מטתו ליום תשעים כאילו שופך דמים מנא ידע אלא אמר אביי משמש והולך (תהלים קטז, ו) ושומר פתאים ה' 

The Sages taught in a baraita: With regard to one who engages in intercourse with his wife on the ninetieth day of her pregnancy, it is as though he spills her blood.The Gemara asks: How does one know that it is the ninetieth day of her pregnancy? Rather, Abaye says: One should go ahead and engage in intercourse with his wife even if it might be the ninetieth day, and rely on God to prevent any ensuing harm, as the verse states: “The Lord preserves the simple” (Psalms 116:6).

Contrary to the Talmud’s assertion, there is no association with the frequency of intercourse during pregnancy and the danger of a miscarriage. Here is what the Mayo Clinic tells patients:

Your developing baby is protected by the amniotic fluid in your uterus, as well as by the strong muscles of the uterus itself. Sexual activity won't affect your baby, as long as you don't have complications such as preterm labor or placenta problems…

Having sex during pregnancy won't provoke a miscarriage. Most miscarriages occur because the fetus isn't developing normally.

“יש ניהגיס כשנכנסה אשתו בחדש ט׳ לעיבורה לעשות בחדש ההוא מצות פתיחת ההיכל והוא מנהג יפה

There is a custom during the ninth month a woman’s pregnancy to give her husband the mitzvah of opening the ark. And this is a good custom”

— כף היים ס ׳ קלד, יב By Rabbi Yaakov Chaim Sofer, (1870-1939).

You may have heard about a Jewish folk remedy (a segulah) believed to help start the process of labor in a woman ready to give birth. It is to give her husband the honor of opening the ark during the service in the synagogue. I am not aware of any randomized clinical trial of the belief, but there have been randomized trials of another claim, this one perhaps a little more widespread. That claim is that intercourse late in pregnancy will induce labor.

It goes way back to Aristotle in the fourth century BCE, who wrote that “women who have a connection with their husbands shortly before childbirth are delivered all the more quickly.” However Soranus, another Greek physician who lived in the third century CE (and about 500 years after Aristotle) believed that any intercourse during pregnancy was harmful. Here is what he wrote in his textbook of gynecology:

Sexual intercourse however is always harmful to pregnant women both on account of the tossing motion and because the uterus is forced to submit to a movement which is contrary to the progress of pregnancy. And even more so in the last months lest because of it the chorion burst and the fluid which has been prepared for use in parturition be evacuated before the proper time.

“It is important to find a scientific answer to this issue” wrote a team of researchers in Portugal, “because if it is proven to be true, a decrease in the number of medical interventions for post-term pregnancy can occur.” So they randomized pregnant women to two groups: “vaginal intercourse at least twice a week or abstinence.” Yes, you read that correctly. 63 women and their lucky partners were assigned to the intervention group and 60 to the control. And there were no significant differences between the rates of spontaneous onset of labor in the two groups. A 2019 review from the School of Medicine in Naples Italy concluded that “in women with singleton [i.e. not twins], cephalic [head down], low-risk pregnancies, sexual intercourse at term does not significantly increase the incidence of spontaneous onset of labor.” So that myth is now officially busted.

Next time, on Talmudology: The Zov and Gonorrhea.