Anatomical and pathophysiological features of fetal circulation in the umbilical-portal venous system

Being facilitated in recent years by the advent of high-resolution gray-scale, color Doppler and three-dimensional ultrasound, prenatal visualization of venous vessels has improved much and well contributed to a better understanding of the value of fetal venous circulation. The fetal liver plays an important role in ensuring normal fetal blood circulation, receiving up to 7080% of venous return from the placenta. Of particular importance is its role in the regulation of intrauterine growth. Venous inflow to the fetal liver is significantly influenced by maternal factors. Ultrasound evaluation of the fetal venous system remains to be not an easy task. This article discusses the significance and features of the anatomical and functional development of the fetal intrahepatic venous system.