The aim of this work was to study the reaction of coagulation hemostasis in response to hypoxia in rats young and mature, exposed to hypoxia in the embryonic, prefetal and fetal stages of prenatal ontogenesis. With the help of some hematological tests, a comparative analysis of blood coagulation indices was performed, both of males and females of experimental and control rats. To assess the general condition of the blood coagulation system, the time of clot formation, the time of plasma recalcification, and the concentration of fibrinogen were determined to assess the final stage. A comparative analysis of the data showed that intrauterine hypoxia of the fetus causes a significant change in blood coagulation. The opposite effect of prenatal hypoxia depending on the degree of development was revealed. So, in one-month-old rats, a hypocoagulation shift was established. Since weakened blood coagulability was detected in experimental animals. And in six-month-old experimental rats, a hypercoagulable shift in the system was observed, an increase in blood coagulation was recorded compared with control animals. The degree of severity of the changes occurring in the body during hypoxia (regardless of the cause), determined by the duration, intensity of oxygen deficiency, and in what period of embryonic development the same as its effect. It turned out that the embryonic period of fetal development is more susceptible to the effects of hypoxia. It is assumed that prenatal hypoxia forms a new ratio of hemocoagulation factors. We can say that the level of these shifts was determined by the severity of hypoxia, and the observed changes were associated not with an increase or decrease in the concentration of one coagulation factor, but with a shift in the dynamic equilibrium of the entire system.