Fetal Growth Restriction Is Associated With Prioritization of Umbilical Blood Flow to the Left Hepatic Lobe at the Expense of the Right Lobe

Department of Clinical Medicine, University of Bergen, Bergen, Norway.
Pediatric Research (Impact Factor: 2.31). 04/2009; 66(1):113-7. DOI: 10.1203/PDR.0b013e3181a29077
Source: PubMed


Eighty to 85% of the venous perfusion to the fetal liver is from the umbilical vein, the rest from the portal vein. Umbilical venous flow to the liver is essential for intrauterine growth, and is impaired in placental insufficiency. We hypothesized that in growth-restricted fetuses portal blood flow compensates for insufficient umbilical blood flow to the liver. In 29 fetuses with fetal growth restriction (estimated fetal weight < or =5th percentile), we used ultrasound to measure blood flows in the umbilical vein, ductus venosus, left portal vein, and main portal stem. Compared with normal fetuses, both absolute and normalized total venous liver blood flows were reduced in growth-restricted fetuses, related to the degree of placental compromise and equally affecting both liver lobes. However, portal replaced umbilical flow to the right lobe, in a manner graded according to placental vascular resistance; in extreme cases, the right lobe received no umbilical perfusion. In fetal growth restriction, the liver suffers from venous hypoperfusion, and portal blood partially replaces umbilical flow to the right lobe; this will result in right liver lobe hypoxemia. This striking prioritization in nutrient delivery of left over right lobes suggests an adaptive response to poor placental perfusion that may have functional consequences.

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Available from: Jörg Kessler
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    • "There is a finely tuned distribution between these sources with 85% umbilical blood as the main venous supply [4]. In cases of reduced umbilical circulation and fetal growth restriction, the portal contribution [5] and hepatic artery hemodynamics [6] suggest operation of a buffer response in the human fetus [7] which partially compensate the low umbilical flow, but with a reduced oxygenation of the right liver lobe as a consequence . Assuming that the fetal liver in such conditions is at increased risk of hypoxic injury, we hypothesize that alanine (ALT) and aspartate (AST) aminotransferases are increased in fetuses with IUGR. "
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