For generations, couples hoping for a baby boy have tried everything from special diets to carefully timing intercourse around ovulation.
The internet has made these theories even more popular. Search for “how to have a boy” and you will find countless calendars, calculators, foods and techniques claiming to influence whether the next baby will be male or female.
But there is an important distinction between popular theories and methods supported by reproductive medicine.
In natural conception, the egg contributes an X chromosome, while sperm can contribute either an X or a Y chromosome. An embryo with XX chromosomes typically develops as female, while XY typically develops as male.
That means the sperm determines the chromosomal sex of the embryo.
Does timing intercourse help conceive a boy?
One of the best known theories suggests having intercourse as close as possible to ovulation.
The idea is that sperm carrying a Y chromosome may reach the egg faster but survive for less time than sperm carrying an X chromosome. Under this theory, intercourse immediately before or during ovulation would supposedly favor a boy.
It sounds convincing, but there is no reliable clinical evidence that couples can use intercourse timing to predictably choose their baby's sex.
Tracking ovulation can certainly help couples identify their fertile window and improve their chances of conception, but it should not be considered a proven method for conceiving a boy.
What about sexual positions?
Another popular claim is that positions allowing deeper penetration favor Y carrying sperm because they are deposited closer to the cervix.
Again, there is no convincing scientific evidence showing that sexual position changes the probability of having a boy.
The same applies to claims involving female orgasm or the time of day when intercourse occurs.
Can food increase the chances?
Online advice frequently recommends foods rich in potassium and sodium, including bananas, potatoes and certain meats, for couples trying to conceive a boy.
Other theories suggest changing the mother's vaginal pH or following highly specific diets before conception.
These methods have not been demonstrated to reliably determine a baby's sex. Couples should also be cautious about extreme diets or supplements, particularly when preparing for pregnancy.
Good nutrition before conception matters for the health of the mother and developing baby, but it is not a proven natural sex selection technique.
What about the Chinese gender calendar?
The famous Chinese gender calendar attempts to predict a baby's sex using the mother's age and month of conception.
It can be entertaining to try, but there is no established biological mechanism that would allow such a calendar to determine whether conception produces a boy or girl.
The same applies to lunar calendars and many traditional prediction methods used around the world.
Is there actually a medical way to choose?
Modern reproductive medicine changes the answer.
With IVF and preimplantation genetic testing, doctors can obtain information about an embryo's chromosomes before it is transferred to the uterus. This can reveal the chromosomal sex of embryos and potentially allow selection of an embryo for transfer.
The American Society for Reproductive Medicine confirms that PGT can make the sex of embryos known before transfer. However, using IVF specifically for nonmedical sex selection remains ethically controversial, and availability depends on clinic policies and local laws.
IVF is also a significant medical procedure with costs and risks. ASRM says sex selection for nonmedical reasons should not be encouraged and stresses that patients considering it need appropriate counseling about the procedure.
So, can you naturally increase your chances of having a boy?
This is where many viral articles give couples false hope.
There is currently no scientifically proven natural technique that can reliably make a couple conceive a boy.
Ovulation timing, sexual positions, special diets and traditional calendars may be interesting theories, but none provides a dependable way of choosing a baby's sex.
For couples conceiving naturally, whether the next child is a boy or girl remains largely a matter of biology and chance.
And perhaps that is why the question continues to fascinate parents around the world.
