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2011-08-15-12 Case of the week #307 © Deblieck

Answer to the case of the week #307

November 24, 2011 - December 8, 2011

Case report

A 24-year-old woman with non-contributive history presented to our unit at 29th week of pregnancy. Our examination revealed following findings:
  • two vessel umbilical cord (single umbilical artery type IV)
  • persistent right umbilical vein (PRUV)
  • duplication of the fetal gallbladder
The newborn was delivered at 39 weeks (male, 4020 g, 55 cm, Apgar score: 09, 10, 10) and the prenatal findings were confirmed. Postnatal course of the newborn was normal.

In our case the finding of the single umbilical artery was associated with doubled gallbladder. According Boyden's classification [1] following types of the gallbladder duplications exist:

According to older study of Blackburn and Cooley [2] four types of single umbilical artery exist (Table 1):

Table 1: Plausible types of single umbilical artery according to Blackburn and Cooley [1].
TYPE Frequency Number of umbilical cord vessels Origin of single umbilical artery (SUA) Umbilical vein Associated anomalies
I Most common (98%) 2 Allantoic derivation; SUA originates from either the left or right common iliac artery Left Abnormalities of the central nervous system, lower genitourinary tract, short umbilical cord syndrome, acardia
II 1,5% 2 Vitelline derivation; SUA originates from the superior mesenteric artery Left Severe fetal malformations - sirenomelia, caudal regression, anal agenesis. Normal fetal development was also reported.
III Rare 3 1 SUA - of allantoic or vitelline origin 2 umbilical veins - left and persistent right Poor prognosis, anomalous pulmonary venous return, renal agenesis, ipsilateral limb reduction, unicornuate uterus, hydranencephaly.
IV Rare 2 1 SUA - of allantoic or vitelline origin Right Embryonic lost before prenatal or pathological assessment was possible

As the table 1 shows, our case represents a rare type of the single umbilical artery (type IV). Normal course and outcome of the pregnancy is in contradiction with Blackburn and Cooley work.

Newer review (Weichert et al., 2011 [4]) reports 0.08% incidence of the persistent right umbilical artery and found it as an isolated finding in nearly 75% of cases, while 25.6 % were associated with other anomalies (cardiovascular, gastrointestinal, renal, cerebral, limb abnormalities).  7.9% of non-isolated persistent right umbilical veins had aneuploidies (trisomy 18, Turner syndrome) and so in these cases karyotype examination might be reasonable [4].

In the review of Weichert et al [4], only two cases (0.7%) had association of the persistent right umbilical vein with sigle umbilical artery - type IV (as it was in our case), but the outcome was excellent, which is again in contradiction with previous studies (Blackburn and Cooley [2]).
Images 1, 2, 3, 4: Images show slightly oblique transverse abdominal scans at the level of the initial inlet portion of the umbilical vein into the fetal abdomen. The inlet is on the right side of the doubled gallbladder (which is also clearly visible) and further direction of the umbilical vein is oriented towards the fetal stomach.



Images 5, 6: Image 5 shows a cross section of the umbilical cord with just two vessels (single umbilical artery and umbilical vein). Image 6 shows normal flow within the ductus venosus.


Images 7, 8: Images represent drawings comparing normal arrangement of organs at the level of transverse section of fetal abdomen (Image 7) and abnormal arrangement presented in our case (Image 8). Small part of the images in their right upper corner depicts transverse section of the umbilical cord - normal three-vessel cord (Image 7) and abnormal two-vessel cord - right umbilical vein and single umbilical artery (Image 8) - type IV of the single umbilical artery. Doubled gallbladder and its position is also depicted on the Image 8.
UV - umbilical vein; RUV - right umbilical vein; GB - gallbladder; IVC - inferior vena cava; Ao - aorta.

Videos 1, 2: Videos show slightly oblique transverse abdominal scans at the level of the initial inlet portion of the umbilical vein into the fetal abdomen. The inlet is on the right side of the doubled gallbladder (which is also clearly visible) and further direction of the umbilical vein is oriented towards the fetal stomach.


Postnatal findings

Videos 3, 4: The videos show postnatal finding of the doubled gallbladder.



1. Boyden EA. The accessory gall-bladder—an embryological and comparative study of aberrant biliary vesicles occurring in man and the domestic mammals. Am J Anat 1926;38:177-231.
2. Blackburn W, Cooley W. Umbilical cord. In: Stevenson, Hall and Goodman (eds.). Human Malformations and related anomalies, vol II, pp.1275. New York: Oxford University Press.
3. Persutte WH, Hobbins J. Single umbilical artery: a clinical enigma in modern prenatal diagnosis. Ultrasound Obstet Gynecol. 1995 Sep;6(3):216-29.
4. Weichert J, Hartge D, Germer U, Axt-Fliedner R, Gembruch U. Persistent right umbilical vein: a prenatal condition worth mentioning? Ultrasound Obstet Gynecol. 2011 May;37(5):543-8. doi: 10.1002/uog.7764. Epub 2011 Mar 25. Review.
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