What does the sex of the child depend on?

The sex of the child – what does it depend on?

The sex chromosomes are responsible for the human gender, the genetic sex. Every healthy person has 1 pair of sex chromosomes. In women it is the XX pair and in men the XY pair. This means that the child always receives an X chromosome from the mother (or more precisely from her egg cell). It is the father who in a way determines the sex of the child. If the X chromosome is also transferred from him (the sperm), a girl is born, if the Y chromosome is transferred, a boy is born. This article is only about genetics and normal inheritance. It is important to think about the occurrence of an abnormal number of chromosomes, e.g. Turner syndrome (a girl with an X chromosome).

How to find out the sex of your baby

Society describes “ways” to determine the sex of the intended child. Many people believe in a theory related to the survival time of certain sperm. According to this theory, sperm with an X chromosome are slower but can survive longer in the vagina. This means that if sexual intercourse took place a few days before ovulation, the chance of giving birth to a girl is theoretically greater. This is because sperm with the Y chromosome are faster and have a shorter lifespan. So to give birth to a boy, the couple should have sexual intercourse on the day of ovulation or the day before. However, there are no scientific studies that confirm the effectiveness of this technique. There is also a method that refers to the difference in the electrical potential of the sperm. However, it can be assumed that the chance of meeting the desired sex of the child is always 50 %, regardless of the methods used.

The only medical ways to determine the sex of a child are the IVF procedure and sperm clustering. This is most often used for inherited sex-linked diseases. To avoid their occurrence in the child, it is then necessary to “plan” the sex of the child.

When can you tell the sex of the baby?

The sex of the baby is determined by the sperm when the egg is fertilised. Up to a certain point, however, the embryos develop in the same way and it is not possible to distinguish the sex on the ultrasound. Usually, however, this is possible from the 12th week of pregnancy. Much depends on the quality of the equipment, the experience of the doctor, but above all on the position of the baby in the uterine cavity. In many cases, babies do not want to show their sex for a long time. In case of doubt, the 3D technique of ultrasound can be helpful. The sex of the baby is also determined in non-invasive prenatal tests and with 100 per cent certainty in a karyotype test after an invasive test such as diagnostic amniocentesis.

The sex of the child – myths

A few decades ago, when ultrasound examinations were not as common and accurate as they are today, the sex of the baby often remained a mystery until birth. Therefore, all kinds of theories were developed to predict the sex of the baby. The most popular was the method related to judging the shape of the future mother’s belly. It was believed that a round belly stood for a daughter and a pointed belly for a son. The beauty of the pregnant woman was also analysed. A boy was attributed to her and a girl was subtracted. What the expectant mother craved – sweet or sour – was also important. However, these are myths that have been repeated over the years and mainly stemmed from the desire at the time to predict gender without the modern technologies available today.