People, and parents-to-be in particular, have always been interested in the gender of a child even before it is born.

Few people don't think about the subject at all, because at the latest when you are asked by the outside world what you prefer, you have to show your colours. Even if the answer is something like "it doesn't matter, the main thing is that it's healthy", expectant parents often find themselves thinking or daydreaming about the shape or gender of their baby.

The fact that Mother Nature intended that you only find out the sex of your child at birth has long since been circumvented by the invention of ultrasound examinations. From around the 20th week, and in some cases earlier, a doctor can use ultrasound to determine with some certainty whether the baby is a boy or a girl.

However, it would not be the first time that such predictions have led to errors, or that the child has kept its secret to the end by consistently adopting positions that do not make a determination possible.

There have been parents who were absolutely convinced that they had chosen the right girl's or boy's name, only to have to improvise because the name didn't fit after all.

To avoid this, particularly eager parents try to take control even before the birth or conception of their offspring. According to some studies, male sperm with the Y chromosome for boys are said to be smaller, faster and shorter-lived, which makes fertilisation by them just before or on the day of ovulation more likely. Furthermore, the more frequent sexual intercourse around the day of ovulation, the better.

For girls, their X chromosome sperm are larger, slower and longer-lived, and should therefore ideally be sent on their journey to the uterus and fallopian tubes a few days before ovulation so that they can arrive there on time, while the Y chromosomes fall by the wayside.

It is now even possible to determine the sex by blood test, but doctors are not allowed to disclose the result before the 12th week, as this is intended to prevent abortions of children of the "wrong" sex, which could still be carried out legally in many places up to three months. This test is not freely available and is currently only offered by a few doctors.

The age of the mother is also said to have an influence on the sex of the child. It has been shown that more girls are born as the age of the mother increases, and then more boys are born from the mid-forties onwards, although there are generally fewer births then.

But even during pregnancy, there are supposed to be some indicators that point to gender. These often originate from old wives' tales and are by no means scientifically proven, but are nevertheless very popular.

It is claimed, among other things, that the belly takes on a different shape in boys and girls, with the former having a pointed shape, set high up, and the latter being wide and round at the bottom.

The pendulum should also be able to provide information: if it swings in a circle, it is a girl, if it swings back and forth, it is a boy.

If you have an appetite for sweets, it will be a girl, if you have an appetite for sour and savoury food, it will be a boy.

But the father also has to serve as the basis for some of these old wives' tales: if he puts on weight with the pregnant woman, he will have a boy; if he doesn't, the couple will have a girl.

Whether you believe this or not is up to you. It is interesting to see whether there might be a grain of truth in it.