[Umbilical blood flow relations in different segments of the umbilical cord. Part 1. Physiologic index constellation].

Based on a collective of 500 women with normal singleton pregnancies we examined the indices of flow resistance along the umbilical cord. Measurements were taken at the foetal abdominal side of the Aa. umbilicales on the one hand and at the placental insertion of the vessels on the other. According to our results we were able to establish a physiological constellation of the indices for each week of gestation, and - subsequently - for the whole duration of pregnancy. These constellations could be considered physiological. They may serve as a basis for the definition of pathological conditions.