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23-09-2026
To create new life, an egg and a sperm cell are needed. An egg contains half of the mother's genetic material, and the sperm cell contains half of the father's genetic material.
All your genetic material is written on chromosomes. Normally, you have 46 chromosomes: you received 23 from your mother and 23 from your father. They determine the colour of your eyes, the colour of your hair, the size of your nose and so on. Your sex is also recorded on them: “XX” is a girl and “XY” is a boy.
A mother is “XX”; when she passes on half, you therefore always get an “X”, so an egg always contains an “X”. A father is “XY”. Half of this is therefore either “X” or “Y”. So it depends on whether an “X” sperm cell fertilises the egg or whether a “Y” sperm cell wins the race. From that moment on, it is settled whether you will be a boy or a girl. In short, the sperm cell determines the sex of the child.
Many people wonder whether you can influence the sex of your baby during pregnancy or before conception. There are various theories about methods that are said to increase the chance of a boy or a girl. But are these theories actually true?
The Y chromosome is slightly lighter than the X chromosome, which means that Y sperm cells may swim slightly faster than X sperm cells. However, this difference is minimal. Even so, it forms the basis of various hypotheses claiming that you can influence the sex by timing intercourse:
In practice, however, these methods do not work. With IUI treatment, for example, insemination always takes place around ovulation, and the number of boys and girls born is equally divided.
Scientists have tried to separate X and Y sperm cells using techniques such as centrifugation or microscopic analysis. To date, this has not proved successful.
Some people believe that a specific diet can help influence the sex of the baby during pregnancy. A healthy diet is essential for a healthy pregnancy, but there is no scientific evidence that diet has any effect on sex determination.
In some cases, there may be a medical reason to determine the sex, for example if a hereditary condition only occurs in boys. In such cases, embryos can be tested in a laboratory, but this method is not used for a sex preference without a medical reason.
At present, there are no proven methods of influencing the sex of your baby. The chance of a boy or a girl remains roughly 50/50. Although there are many theories about influencing the sex, it remains largely a matter of chance.
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