There is only one method proven to be effective when it comes to choosing the sex of a baby, but in many countries, it is only allowed for medical reasons.
What determines the sex of the child?
The sex of a baby depends on which particular sperm ends up fertilizing the egg. If it carries the sex chromosome X, a girl will be conceived. If it’s a Y chromosome, the baby will be born a boy. As a rule, sperm contains roughly the same amount of X and Y chromosomes carriers [1].
So the chances of conceiving a girl or a boy are 50-50?
According to the United Nations Population Fund, there are 102-106 boys per 100 newborn girls [2]. So the chances of having a male child are slightly higher. Reproductive experts confirm this pattern, as 51% of babies conceived through IVF are boys [3].
Are there any old wives’ tales that work when trying to plan a baby’s sex?
Probably not. Since the middle of the last century, the Shettles method has been especially popular. Allegedly, sex during ovulation leads to the conception of a girl and sex a few days before ovulation to that of a boy. The doctor who created the method gave scientific-sounding explanations, which were partially confirmed by research [4]. But scientists quickly abandoned the notion, concluding that there were more important things to study.
Is it true that with IVF, you can choose the sex of the child?
In classic IVF, neither parents nor doctors know the sex of the embryo transferred to the uterine cavity. There is one technology that allows you to determine the sex in advance, it’s called preimplantation genetic testing (PGT-A). Several cells are taken from the embryo and their chromosome set is examined. This method allows for the detection of a range of issues, and at the same time, doctors can find out the sex of the embryo.
In most countries, PGT-A can't be ordered just for the sake of favoring one sex over the other; there has to be a medical reason for conducting the procedure, for example, in the likelihood of a genetic disease passed to the baby by either the male or female line. In such cases, choosing the gender increases the possibility of having a healthy child [5]. If PGT-A is performed, but there is no connection between gender and genetic disease, the parents can decide whether they want to know the sex of the embryo before the transfer.
Countries such as the United States and Mexico do not specifically regulate gender selection of this sort, and some of their IVF clinics are widely chosen by people from other countries with stricter laws when trying to conceive either a boy or a girl. The bioethics of gender selection is debatable and often controversial [6].
