2007-04-24-09 Umbilical vein varix © Goubaa www.thefetus.net/
Umbilical vein varix
Mohamed Goubaa, MD.
Fetal intra-abdominal umbilical vein varix is a focal variceal dilatation of the umbilical vein. Its clinical importance has not yet been clearly established, but it has been reported to be associated with increased fetal malformations, chromosomal abnormalities and increased and death rate [1, 5].
We describe one case of dilation or varix of the umbilical vein appearing as a fetal intra-abdominal cyst at 28 weeks of pregnancy in a 21-year-old female (G2P1). Doppler or color flow examination indicated umbilical venous flow within the cystic area in the case. This infant was delivered at term without sequelae.
Images 1, 2: 28th week of pregnancy; transverse abdominal scans. Power Doppler (image 1) and color Doppler (image 2) images showing umbilical vein varix.
Images 3, 4: 28th week of pregnancy; transverse abdominal scans. Color Doppler (image 3) and gray-scale (image 4) images showing umbilical vein varix.
Image 5: 28th week of pregnancy; oblique transverse abdominal gray-scale image showing umbilical vein varix.
The umbilical vein was considered dilated when the measurement was above 2 standard deviation of the mean for gestational age [3, 4]. Association of the presence of umbilical vein varix and fetal anomalies and/or obstetrical complications has been reported in literature . Additional sonographic abnormalities were detected prenatally in 31.9%, most commonly anomalies of the cardiovascular system (including structural and functional abnormalities), hydropic features and anemia. Chromosomal abnormalities were detected in 12% and recently it has been suggested that this prenatal finding should be considered as a soft marker for aneuploidy. Mortality associated with the umbilical vein varix has been reported between 24-44% .
In presence of umbilical vein varix fetal echocardiography and detailed ultrasound study of fetal anatomy is needed to exclude associated anomalies. Isoimmunization should be ruled out, and consideration of karyotyping should be discussed. Serial follow-up scans are needed to exclude the onset of hydrops or thrombosis of the varix . A close fetal monitoring by serial color Doppler and ultrasonographic examinations should be performed [3, 4, 6].
Sepulveda  conclude that fetuses with varix of the intra-fetal umbilical vein should be considered at risk for poor outcome. However, if no other anomalies are present, the prognosis is generally good .
Differential diagnosis includes other abdominal cysts such as choledochal, mesenteric or urachal cysts. The presence of intra-abdominal umbilical vein varix can be confirmed by color Doppler finding of turbulent flow in the cystic mass.
A varix of intra-fetal umbilical vein is considered a poor prognostic sign; if no associated anomalies are present, the prognosis is generally good .
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