Een jongetje of een meisje? A boy or a girl?


A baby boy or a baby girl?



Without new technologies where one could possibly  manipulate the “preference for a boy or girl”

it is clear that only the Holy One decides who will come on this earth.  


But as there seems to be a hint / remez in the Torah -in past weeks parshat Tazria[-Metzora-] about the “mechanism” of which gender will be born, I would like to write you some fascinating insights about this issue.

[I could not have done this clearly without seeing the commentary on the second verse of Tazria [from the Artscroll book:

Sforno: commentary on the Torah by  Rav Pelcovitz ][ beautiful explanation of the  commentary of the Sforno]

As you may know Sforno was also a doctor  and lived in  Italy [ later in his life in Bologna ]  where he taught Torah and where he practiced medicine and was famous as a doctor till the end of his life [ 1550] .

Indeed about this issues of gender and time of tashmish [ intercourse] there have been written as far as I remember some popular works  in the past touching on the main principles and I suppose that there will be also quite a bit of Jewish literature about this which I am nor aware of.



I sent you a while ago an E-mail about some basic principle of genetics and I will try to send with this E-mail as an attachment of the “genetic article"[so that I don’t have to explain again too much about  chromosomes here]


I copy now the second verse of parshat Tazria


2 Speak unto the children of Israel, saying: If a woman conceives ["tazria in hebrew"], and bear a man-child, 

then she shall be unclean seven days; as in the days of the impurity of her sickness shall

she be unclean.

Our Rabbis interpreted this verse as to indicate that if a women first "emits seed”[zera,which is contained in the word tazri means : seed]  a baby-BOY is likely to be born.

Emits seed must mean here of course : ovulation [biutz]

The language of commentary of the S'forno on this verse is not easy to understand but it is beautifully explained by Rav Pelcovitz [where he acknowledge the assistance of Dr. Fred Rosner and Rav David Cohen]which I will explain now-with little changes-with my own words .


If the women ovulates first before the man emits its seed [sperm] then the egg of the women will already have lost some of its “vitality” when the man emits its seed[ejaculates] and the sperm of the man will be dominant[=stronger] in comparison to the "already a few hours/days older" egg.


If the women ovulates later -after the man emits his seed- then the opposite will be the case: the male seed [sperm] may loose some of its potency and the egg will be dominant.

What is known for long is that the vaginal fluid in the women is normally acid [low ph][chumtzit]

When she ovulates the vaginal fluid becomes [more] alkaline.

Now read carefully, please:

Remember that the “seed” of man and women are different:

The egg contains 2 X chromosomes and  sperm one X and one Y chromosome. The woman can only contribute an X , the man an X or Y.

An X from the woman may combine with an X from the man ……XX = a girl   or with anY from the man………XY = a boy  

[In other words: only the Y will give rise to a boy if it melts with the X chromosome of the woman but if the X chromosome from the man melts with one of the X chromosomes of the woman  a girl will be the result]


The Y chromosome is not very “happy” in an acid enviroment

If the vaginal fluid is acid [that is before the ovulation!] then there is a big chance that the male Y chromosome of the sperm [which decides if there will be a boy] will not survive in this acidity and that the surviving X chromosome from the man will join the X chromosome from the woman which will result in a baby-girl.


As we said before during ovulation the vaginal fluid becomes more alkaline and the Y chromosome [which prefers an alkaline environment] has suddenly a far bigger chance of surviving] so that it can join now with the X chromosome of the women and we get a boy [XY]

Now it becomes medically understandable what the Torah means if it states:



 If a woman conceives [tazria], and bear a man-child............Read as follow to understand the verse: If a women tazria[in Hebrew=gives off her seed  first = ovulates first................ the result will be [very likely] a male child!]

This is because the condition in the vagina after ovulation will give rise to an alkaline environment[caused by the ovulation] and the Y chromosome will have a far better chance to survive and  combine with the woman X chromosome [ XY = boy]


As this is a real  Torah subject, combined with medical ideas I would be happy to receive any comment from you which may enlighten things further .


B”H -time allowing and if I find further proper material I would like to write you may be some more about this subject in the future and I also would be happy to receive any articles from you- if you know about them- written on the "boy-girl" subject , as mentioned above.