In this study we compared the distribution of blood flow to the liver in growth-retarded fetuses whose estimated weight was < 5th centile with normal-weight fetuses. As expected, the relative venous blood flow to the liver was reduced, with blood flowing preferentially through the ductus venosus. However, the total blood supply seemed to be maintained by a concomitant, significant increase in arterial blood flow through the hepatic artery. Absolute flow velocities such as the peak, minimum diastolic and temporal average velocities were changed, as was the flow waveform. Effectively, the deficiency in venous supply was made up for by an increase in arterial blood flow. This compensatory effect may be crucial for maintaining liver function in times of low portal venous blood supply. It thus makes sense to regard the liver as the fourth preferential organ for arterial blood supply in the compromised fetus, besides heart, brain, and adrenals.