Purpose: The aim of this study was to evaluate whether the dual hepatic blood supply is altered in healthy pregnant women compared with that in nonpregnant women.
Materials and methods: Flow wave-forms in common hepatic artery and portal vein were obtained in 67 healthy pregnant women at 10-40 weeks gestation and 22 nonpregnant women by using Doppler ultrasonography.
Results: In the nonpregnant group, the mean (SD) hepatic arterial blood flow, portal venous blood flow, and total liver blood flow were 0.57 (0.31) L/min, 1.25 (0.46) L/min, and 1.82 (0.63) L/min, respectively. In the healthy pregnant group, the portal venous blood flow and total liver blood flow significantly increased after 28 weeks gestation. However, the hepatic arterial blood flow remained unchanged during pregnancy. There was no relationship between the hepatic arterial blood flow and the portal venous blood flow.
Conclusion: The results demonstrated that the hepatic perfusion increased during third trimester compared to nonpregnant level. Because the hepatic arterial blood flow remained unchanged during pregnancy, major determinant of the increase in the hepatic perfusion was the portal venous return. The data suggest that the hepatic arterial and portal venous vascular territories have regulatory mechanisms that allow for independent changes during pregnancy.