Functional anatomy of the liver of the human fetus: applications to ultrasonography.

The anatomy of the liver of the human fetus was established on the basis of cadaveric techniques, but its study has been transformed by obstetric ultrasonography. This work is based on a personal study of the normal morphology of the liver of the human fetus and on a review of the current literature, particularly with regards to vascularization. The liver is the digestive organ whose rudiments appear earliest and which develops most rapidly. The development of the liver and its functional segmentation are determined by the oxygenated blood flow in the umbilical vein. The extent of each hepatic territory depends on the quantity of umbilical flow, which determines its development and ensures its function. The fetal liver occupies a very large proportion of the abdominal cavity. It is a vascular organ, closely moulded to the walls of the abdominal cavity and the viscera in contact with it. The left liver is a little more bulky than the right liver and is developed mainly transversely. The morphology of the normal fetal liver appears quite uniform. The intrahepatic umbilical vein and the venous axis prolonging it to the right have a remarkably constant arrangement, well demonstrated by ultrasonography. An assessment of the anatomic features of the afferent veins, the ductus venosus and the efferent veins gives some idea of the conditions of the intrahepatic venous circulation in the human fetus that remain to be demonstrated. At birth, ligature of the umbilical v. brings about a sudden change in the hepatic circulation, resulting in temporary morphologic and functional modifications in the liver.(ABSTRACT TRUNCATED AT 250 WORDS)