Those who have carefully studied biology at school know that a person's sex is determined by a set of chromosomes: in women it is XX, and in men it is XY. At conception, a woman always gives her X chromosome - she simply does not have another, and a man - X or Y. The sex of the child depends on which chromosome the man gives. Therefore, the exactingness and pretentiousness of some fathers - so that a boy must be born - is not scientifically substantiated in any way - what they gave is what they received!
Today, it is possible to determine the sex of the fetus already at 15 weeks of gestation using an ultrasound scan, and most accurately at 23-25 weeks. Usually this definition is reliable and depends only on the knowledge and experience of the doctor conducting the examination.
In addition, there are some folk methods dating back centuries and allowing to predict the sex of the unborn child with a fairly high level of probability. For example, if the belly during pregnancy is round and sticks out to the left, then this is for the girl, and the "cucumber" and to the right - for the boy, strong pigmentation of the skin of a pregnant woman - for the girl, and rapid hair growth - for the boy. Areoles at the nipple of the breast are dark - for a girl, light - for a boy.
There are some methods to predict the sex of the unborn child at conception, that is, to plan in advance your dream of a boy or girl. Of course, such methods do not give one hundred percent guarantee, but they cannot be called ineffective either. The Chinese, for example, calculate the prognosis of the sex of the child using a special ancient table, the Japanese calculate it from the sum of the years of the spouses at the time of conception.
The “blood renewal” planning method is based on the fact that a man's blood is renewed every 4 years in a man's body, while a woman’s blood is renewed every 3 years. Whose blood turned out to be younger, it is of this gender that the child will be conceived at this moment.
The day of the week method is the most modern known. It has been scientifically proven that sperm carriers of the X chromosome live longer than carriers of the Y chromosome, but they are more mobile. Therefore, having correctly calculated the day of ovulation, in order to get a boy, sexual intercourse should be carried out on that day, and for a girl - one or two days before ovulation, since sperm are active for about 3 days.
The pre-abstinence method will increase the chances of getting a girl, and daily intercourse - a boy. This is allegedly due to the fact that during abstinence, a man's body produces special antibodies that block sperm -Y-carriers. Naturally, all these methods are orders for the "stork", since they do not give a full guarantee, but in the end it is important that your child is desirable and healthy, and you can try to realize an unfulfilled dream of a boy or girl using the next chance!