[Does vascularization of the fetal placenta modify end-diastolic blood flow velocity in umbilical arteries? A histometric contribution to the validation of Doppler ultrasound].

The foetal intravillous blood volume was approximately determined in 90 cases, using placental histiometry post partum. This was compared with the Doppler sonographic flow patterns in the umbilical arteries determined during the last week ante partum. A direct dependence was seen: The larger the peripheral vascular tree of the placenta fetalis, the lower the resistance against the blood flow in the umbilical artery, i.e. the higher the enddiastolic blood flow velocities and vice versa. There is a highly significant correlation between the foetal intravillous blood volume and the foetal risks of Caesarean section performed, because of intrauterine asphyxia, growth retardation or reduced foetal outcome.