[Significance of Doppler blood flow studies in twin pregnancies].

Twin pregnancies are characterized by similar uteroplacental but different fetoplacental haemodynamics at the same gestational age. The aim of this study was to investigate the correlation between Doppler blood flow measurements of fetal vessels and the morphological findings of the placenta, fetal growth and signs of fetal hypoxia. The study group consists of 18 twin pregnancies with operative delivery. In all cases the placenta was examined morphologically. We found similar discordancies in the pulsatility index (PI) or the mean blood flow velocity (Vmean) of the fetal aorta (measurements less than 7 days before delivery) and the birth-weight. In twin pregnancies with operative delivery due to fetal indication in 11 out of 12 cases the twin with suspected hypoxia had a relatively lower Vmean and a higher PI value. The association of pathological blood flow velocity waveforms of the umbilical artery, the fetal aorta and the fetal common carotid artery and histomorphological findings of the placenta could be demonstrated.