When expecting an addition to the family, expectant mothers, in addition to the usual joys, often ask questions about the health of the future baby. blood group and Rh factor play an important role not only in the aspect of health, but can also predict the sex of the future child. in the early XX century, scientists established a system of blood groups, determining inheritance from parents.

Austrian scientist Karl Landsteiner made a significant contribution to the study of blood, revealing the specifics of its properties. his work resulted in the system of division by blood groups, which we use today. blood groups are designated by Roman numerals I, II, III, IV, and each of them is characterized by the presence or absence of A and B antigens.

According to Mendel's law, the inheritance of a child's blood type is determined by the genes passed on from the parents. thus, in parents with blood type I, the child will receive a group with the absence of antigens A and B. in the case of a union of spouses with groups I and II, the children will have the corresponding blood groups, and the situation is similar for groups I and III. the owners of group IV can have children with any blood type, except for I.

The inheritance of the Rh factor also obeys genetic laws. a Rh positive factor (DD or Dd) is a dominant trait and a Rh negative (dd) is recessive. a union of heterozygous parents (Dd) has a 75% chance of having a Rh positive child.

Genetics also provides insight into the inheritance of other traits such as eye color, hair color, and musical hearing. traits are divided into dominant and recessive traits, determining the likelihood of their manifestation in a child.

It is important to consider that some features are inherited less predictably, for example, in the union of the owners of blood groups II and III. the exception is the "Bombay phenomenon", when the presence of antigens is not manifested phenotypically.

Finally, the determination of the sex of the future child depends entirely on the chromosome set of the sperm that fertilized the egg. a male sperm can carry both the X and Y chromosome, determining the sex of the child. thus, the genetic contribution of the father is responsible for the sex of the baby.

While expecting a baby, future parents can have a genetic analysis that will help predict not only the blood type and Rh factor, but also other hereditary features of the future baby.