The objectives of the study are groups of women with a gestation period of 16 to 34 weeks. The first group consisted of 100 women with the threat of miscarriage. 82% (82 women) of them were under threat of preterm delivery, 15% of them (15 women) were under the threat of abortion and 3% (3 women) were undergoing abortion. The second group included 20 women with normal pregnancy that underwent routine examinations. The aim of the research work is to study the anatomical and physiological features of vascular and fetoplacental systems as predisposing factors for the development of the threat of miscarriage. The study was carried out with the help of ultrasound, morphometry, statistical method using a PC soft Statistica 10. To study the correlation relationships the Spearman coefficient was... used. The results of the study have shown that uterine artery in women with threatened miscarriage are larger in comparison to women with normal pregnancy. First the correlation of morphometric indices of uterine arteries in pregnant women with threat of miscarriage, both among themselves and with the sizes of the foetus, as well as fetometric parameters with thickness of the placenta, and fetal presentation was shown. It was shown that the anatomical features of the uterine arteries have a direct impact on the development of the foetus. The localization of the placenta in the most blood-supplied part of the uterus is a prerequisite for the normal course of pregnancy, while the attachment of the placenta in the uterine wall, which is characterized by less blood supply, contributes to the development of the threat of miscarriage. Also, the placental thickness as a predisposing factor to miscarriage was shown. The economic efficiency and importance of the work is extremely high, because knowledge of anatomical prerequisites for the threat of miscarriage will allow in the early stages to identify the risk groups of pregnant women, to include them in the prevention program and thereby reduce the risk of miscarriage. This, in turn, can increase fertility, reduce reproductive losses and have a beneficial effect on the demographic situation. We are planning to continue research on this topic and aim to establish the anatomical prerequisites for violations of fetal development.