Beti Ki Paidaish Kiyun Hoti Hai: The Genetics, Explained Simply
A mother is blamed at the in-laws’ dinner table for having “only daughters,” as if she chose it, as if she could have chosen otherwise. She could not have. High school biology settled this question decades ago, and it settled it in a direction nobody expects to hear out loud: the father’s chromosome decides it, not the mother’s.
Beti ki paidaish kiyun hoti hai: the basic science, plainly
Every human cell carries 23 pairs of chromosomes. One pair determines biological sex: two X chromosomes make a female, one X and one Y makes a male. A mother’s egg always carries an X chromosome, since she only has X chromosomes to give. A father’s sperm carries either an X or a Y, since he has one of each. Whichever sperm fertilises the egg decides the outcome: an X-carrying sperm plus the mother’s X makes XX, a daughter; a Y-carrying sperm plus the mother’s X makes XY, a son.
That is the entire mechanism. There is no dietary trick, timing method, position, or prayer ritual that reliably tips this odds toward one sex over the other, and there is certainly nothing the mother’s body does to “decide” it. The coin, so to speak, is flipped entirely on the father’s side, at the moment of fertilisation, by chance.
In brief
- Who determines the baby’s sex: the father, through the X or Y chromosome in his sperm
- The mother’s contribution: always an X chromosome, the same for every pregnancy
- The odds each pregnancy: roughly close to 50-50 for a son or daughter, independent of previous children
- What does not change the odds: diet, timing of intercourse relative to ovulation by folk methods, position, prayer, or “trying harder”
- Legal note: sex determination and sex-selective practices are restricted or banned in much of the region precisely because of this pressure
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Why “she keeps having girls” is not a pattern that means anything
Because each pregnancy is an independent event, a family having three, four or five daughters in a row is unusual but not remotely impossible or meaningful. It is the same as flipping a coin and getting several heads in a row: unlikely for any specific family to notice, common enough across an entire population that plenty of families experience it. Nothing about a previous pregnancy changes the odds of the next one. There is no accumulating tendency, and there is nothing a woman did, ate or failed to do that caused it.
Rare biological conditions can shift these odds slightly in either direction for some couples, related to specific sperm or reproductive health factors, but these are uncommon, medically diagnosed, and never something to assume or blame a woman for without any testing at all.
The chromosome that decides a baby’s sex was never in the mother’s body to begin with.
Where the myth comes from, and why it persists
Historically, in many cultures, a woman’s fertility and a household’s honour were tied together in ways that made someone need to be at fault when a pregnancy did not produce a desired outcome. Since the mother carries and delivers the child, and since the father’s biological role was not understood or was simply overlooked, blame settled by default on the person who was visibly present through the pregnancy. Modern genetics did not exist to correct this for most of human history, and by the time it did, the social habit of blame had already outlived the ignorance that created it. It survives now mostly through repetition, from mother-in-law to grandmother to auntie, rather than through any real belief that would hold up if someone simply asked a doctor.
Traditional systems including much of classical Unani and Ayurvedic thought, writing centuries before modern genetics, often proposed theories linking a child’s sex to the mother’s diet, the timing of conception, or the “heat” and “cold” balance of the parents at conception. These theories are historically interesting as a record of how earlier scholars tried to explain what they could not yet see, but they do not match what is now known about chromosomes, and none of the associated dietary or timing advice changes a baby’s sex.
What actually affects a pregnancy’s health, since that is the real concern
Families worried about a healthy pregnancy have real, useful things to focus on instead of sex prediction folklore: iron and folic acid supplementation before and during pregnancy, using iodised salt for proper iodine intake, regular antenatal checkups, adequate protein and calorie intake, avoiding smoking and unsupervised medication, and managing existing conditions like diabetes or thyroid disease with a doctor. None of these change a baby’s sex. All of them genuinely change the odds of a healthy baby and a healthy mother, which is the outcome that actually matters.
Sex-selective practices, including using ultrasound to determine sex for the purpose of selective abortion, are illegal in Pakistan, India and Bangladesh, and rightly so, since they cause real harm to families and to women specifically. If a woman is facing pressure, blame or mistreatment over the sex of her children, that is a social and, in some cases, a safety issue, not a medical one, and support from family elders, a doctor, or a local women’s welfare organisation is worth seeking rather than staying silent.
What a doctor actually checks, if something feels genuinely wrong
Occasionally a couple has real, medically relevant difficulty conceiving or carrying pregnancies, which is entirely separate from the sex of previous children and deserves proper medical attention rather than folk explanation in either direction. A doctor investigating fertility looks at both partners: hormone levels, general reproductive health, and in the case of recurrent pregnancy loss, a wider set of tests. None of that workup ever involves “why do we only have daughters,” because that question, medically, already has its answer. Bringing a real fertility concern to a doctor gets it addressed properly; treating it as a sex-selection question wastes time and adds guilt to a couple who have done nothing wrong.
Talking about this without starting a family argument
- Lead with the fact, not the accusation: “the father’s chromosome decides it, it is basic biology” lands better than “you are wrong to blame her.”
- If useful, mention that even doctors explain this the same way in every biology textbook, which removes it from being “your opinion versus theirs.”
- Redirect the conversation toward what genuinely helps a pregnancy: checkups, nutrition, rest, rather than staying stuck on sex prediction.
- If the pressure is repeated and unkind rather than a one-off comment, it is fair to say plainly that the topic is closed for discussion in your home.
Questions people actually ask
Can a man’s diet or health affect whether he has a boy or girl?
Not in any reliably proven way for typical healthy men. A few rare, medically diagnosed sperm-related conditions can shift the odds slightly, but this is uncommon and requires proper testing, not assumption.
Is there any truth to timing intercourse to choose a baby’s sex?
Folk timing methods are not reliable. Some clinical sex-selection techniques exist in fertility medicine for specific medical reasons, done under strict regulation, and are not the same as a home timing method.
Why do some families really have more of one sex than the other?
Chance. With repeated independent 50-50 events, some families will land on a run of the same outcome purely by probability, the same way repeated coin flips sometimes produce several heads in a row.
Is checking a baby’s sex during pregnancy legal?
In Pakistan, India and Bangladesh, laws restrict or criminalise sex determination specifically when linked to sex-selective abortion, due to the serious social harm this has caused. Rules and enforcement vary; check current local regulation.
For pregnancy nutrition basics, see our guide on Desi Remedies for related household health topics covered on this site.