Umbilical and uteroplacental blood flow velocity waveforms in pregnancies with fetal growth retardation.

A 2 MHZ pulsed Doppler ultrasound was used to record blood flow velocity waveforms (FVW) in the umbilical and arcuate arteries of 129 singleton pregnancies where intra-uterine growth retardation (IUGR) was suspected at routine ultrasound screening in the 32nd week of gestation. All patients were examined once a fortnight, between 32nd week and delivery, the results presented being from the final examination before delivery. The FVW were characterized by the pulsatility index (PI). Sixty-six of the 129 newborns were growth-retarded at delivery (birthweight less than or equal to mean--2SD of the general population). Of the IUGR cases, 56% had an abnormal PI (greater than or equal to mean + 2SD of normals) in the umbilical artery and 47% in the arcuate artery. Significant relationships were found between abnormal umbilical artery PI and both IUGR (p less than 0.001) and operative delivery for fetal distress (ODFD) (p less than 0.001). No such relationship was found between abnormal PI in the arcuate artery and either IUGR or ODFD. Four placenta waveform classes (PWC), reflecting the FVW on either side of the placenta, are presented and compared with the outcome of pregnancy. The data show the umbilical artery FVW to be a good predictor of IUGR and intra-uterine fetal distress, whereas the arcuate artery FVW appears to have low predictive value for the above conditions.