The 31 last women 28-35 years were studied at a gestation period of 35-37 weeks with arterial pressure of 140/110-180/120 mm. Hg. The comparison group included 10 successions of women of the same age with a pressure of 110/80-120/80 mm. Hg. in the physiological course of pregnancy. The mass of the afterbirths in both cases was 450-650 g. Histological, histochemical, immunohistochemical and morphometric methods were used to study the arteries of the chorionic plate of the placenta. Clinical studies included dopplerometry and pulsed doppler echocardiography on the Combison-530 Kretztechnik (a sensor with a frequency of 3.5 MHz, a filter frequency of 100 Hz). The quantitative data were processed by the method of variational statistics. Conducted clinical functional studies allowed to establish in pregnant women with hypertension an increase in the pulsation index of the umbilical cord and at the same time a decrease in the minute volume of blood (the cardiac output of the mother). Registered changes in blood flow indicate the development of fetal hypoxia. In conditions of increased pressure, hypertrophy of the wall of the chorion arteries develops, the number of arteries with a functional layer of smooth myocytes in the middle shell increases, as well as vessels of the closing type with intimal muscles actively participating in the regulation of the organ circulation. n arteries with a hypertrophic wall, a high proliferation index of Ki-67 major cell populations were revealed. The level of proliferation of smooth myocytes in the arteries of the chorionic plate in the case of hypertension exceeds by a factor of 1.5 the values of the index of the comparison group. The significant development of smooth myocytes in tunica internal leads to a narrowing of the arteries' lumen, in which only a sliced space is left for the flow of blood, and in some cases-to complete obliteration of the lumen. In conditions of arterial hypertension in the vascular wall, dystrophic changes of smooth myocytes, stromal edema and intravascular thrombi are detected. Identified structural changes lead to a significant decrease in blood volume, the development of acute or chronic placental anemia and, therefore, placental insufficiency and hypoxic conditions in the fetus.