Journal of Ultrasound in Medicine, Vol 13, Issue 10 763-766, Copyright © 1994 by American Institute of Ultrasound in Medicine
Transverse umbilical arterial diameter: technique for the prenatal diagnosis of single umbilical artery
W. H. Persutte and R. R. Lenke
Department of Obstetrics and Gynecology, University of Colorado Health Sciences Center, Denver 80262.
We investigated the relationship between the transverse umbilical arterial
diameter and the presence of a single umbilical artery. Further, we
speculated that fetal physiologic and hemodynamic limitations in
pregnancies complicated by a single umbilical artery would result in larger
umbilical arterial diameters than the typical three-vessel cord. The
identification of a sufficiently large umbilical artery may be
pathognomonic for single umbilical artery. The transverse umbilical
arterial diameter was obtained in 100 consecutive, uncomplicated singleton
pregnancies between 20 and 38 weeks' gestation. These measurements were
compared with the transverse umbilical arterial diameter of 23 pregnancies
in which a single umbilical artery was identified with ultrasonography and
postnatal examination. Transverse umbilical arterial diameter measurements
of the two groups were compared. Before 36 weeks' gestation, all
pregnancies with a single umbilical artery had a transverse umbilical
arterial diameter measurement > 4 mm and all pregnancies with two
umbilical arteries had a transverse umbilical arterial diameter measurement
< or = 4 mm. Because oligohydramnios, multiple pregnancy, or suboptimal
cord position may obscure the expeditious identification of the number of
umbilical cord vessels, measurement of the transverse umbilical arterial
diameter may prove useful in the identification of single umbilical artery.
On the basis of this preliminary evaluation, we suggest that a transverse
umbilical arterial diameter measurement > 4 mm is predictive of single
umbilical artery between 20 and 36 weeks' gestation.
