SINGLE UMBILICAL ARTERY - A DOPPLER FLOW VELOCITY STUDY OF 4 CASES

We measured the pulsatility index of the umbilical artery in four fetu ses identified as having a single umbilical artery. A pulsed color Dop pler ultrasound machine was used and measurements were performed at 4- week intervals following the first diagnosis of single umbilical arter y (week 22-34). The pulsatility index was derived from the mean of fiv e consecutive measurements at the umbilical insertion of the cord, tak ing care to obtain the Doppler signal with an incidence angle between +45-degrees and -15-degrees. All measurements were taken during period s of fetal inactivity. The pulsatility index at 22, 26, 30, 34 and 38 weeks in these pregnancies did not differ significantly from the mean values registered in normal pregnancies. The four women gave birth to babies of normal weight: two were healthy, one suffered from bladder e xtrophy and hemispondyly, the other had bilateral dilatation of the re nal pelves, megalocystis, megalourethra and an imperforate anus.