Endosonographic Doppler flow measurement of the embryonic and fetal umbilical cord

: The blood flow in the umbilical cord was examined via endovaginal Doppler sonography in 30 cases of early pregnancy. For the first time it was possible to examine by Doppler sonography the arterial blood flow in the completed 6th week of pregnancy p.m. With increased duration of gestation there was a continuous increase in arterial blood flow until establishment of a constant flow over the entire cardiac cycle with a constant presence of a diastole in the 14th pregnancy week. Venous blood flow also showed from the 7th pregnancy week p.m. onwards a constant development until attainment of a continuous Doppler flow profile in the 10th pregnancy week. Since the doppler curves of the same gestation period agree with one another, the Doppler profiles obtained in each case can be considered to be both typical and representative. The course of the Doppler flow curves shows the improving performance of the heart of the embryo in the direction of an increasing metabolic exchange between embryo and mature placenta via the increasingly efficient vascular systems.