Fig. 4: Left: This represents an optimal “umbilicus anterior” view of two umbilical arteries (orange) coursing around the fetal bladder (b) by color Doppler ultrasound. Note that the iliac crests (IC) can be seen bilaterally in this 16.5-week fetus. Right: Another axial color Doppler scan at the level of the fetal bladder (b) which is associated with single umbilical artery (orange) in a 16-week fetus.
The prognostic clinical significance of identifying a two-vessel umbilical cord (either as an isolated finding or when associated with other anomalies) during the antenatal period requires further investigation. We routinely screen all fetuses (greater than 16 weeks) for umbilical cord anatomy at our imaging facility. Nonetheless, the identification of this problem should prompt a thorough search for other associated abnormalities. Accurate diagnosis should minimize the number of mothers subjected to unnecessary detailed studies and anxiety in cases of “suspected” but not confirmed SUA. This report documents the appearance of umbilical cord vessels around the bladder by color Doppler ultrasound and correlates this information with normal fetal anatomy. This technique can also be applied to cases where bladder location may be unclear (e.g., bilateral renal agenesis or cloacal exstrophy). Future work at this institution will concentrate upon improving the accuracy of antenatal SUA diagnosis through the supplemental use of color Doppler ultrasound.
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