Related Experiment Video

Updated: Jul 7, 2026

In Vivo Real-Time Study of Drug Effects on Carotid Blood Flow in the Ovine Fetus
11:59

In Vivo Real-Time Study of Drug Effects on Carotid Blood Flow in the Ovine Fetus

Published on: April 28, 2023

Hepatic artery hemodynamics suggest operation of a buffer response in the human fetus

Cathrine Ebbing1, Svein Rasmussen, Keith M Godfrey

  • 1Department of Clinical Medicine, University of Bergen, Norway. cathrine.ebbing@molmed.uib.no

Reproductive Sciences (Thousand Oaks, Calif.)
|February 16, 2008
PubMed

After birth, the hepatic artery buffer response helps to maintain liver perfusion. Here, the authors establish a Doppler technique to measure fetal hepatic artery flow velocity and test the hypothesis that the buffer response also operates prenatally. Women with low-risk pregnancies were recruited to a longitudinal study (N = 161). Measurement techniques and reference ranges for hepatic artery velocities and pulsatility index (PI) were established. Ductus venosus peak velocity (V(DVps)) represented the portocaval pressure gradient, and umbilical venous flow (Q(UV)) represented portal flow. Reference ranges were established for the more accessible left hepatic artery branch. Hepatic artery PI was lower in fetuses with V(DVps) <10th centile (P < .05) and in those with Q(UV) <10th centile ( P < .0001). Conversely, hepatic artery PI was higher in those with Q(UV) >90th centile (P < .0001). The authors establish a method for measuring fetal hepatic arterial blood velocity, provide reference ranges, and show that the hepatic artery buffer response operates prenatally.

More Related Videos

Fetal Mouse Cardiovascular Imaging Using a High-frequency Ultrasound (30/45MHZ) System07:34

Fetal Mouse Cardiovascular Imaging Using a High-frequency Ultrasound (30/45MHZ) System

Published on: May 5, 2018

Hepatic Glucose Production, Ureagenesis, and Lipolysis Quantified using the Perfused Mouse Liver Model06:21

Hepatic Glucose Production, Ureagenesis, and Lipolysis Quantified using the Perfused Mouse Liver Model

Published on: October 6, 2023

Related Concept Videos

Fetal Circulation01:14

Fetal Circulation

Fetal circulation is a unique system that facilitates the exchange of gases, nutrients, and waste products between the developing fetus and the mother. This intricate process takes place through a special organ called the placenta.
Two umbilical arteries transport blood from the fetus to the placenta. At the placenta, the blood absorbs oxygen and nutrients while simultaneously eliminating waste products. This oxygen-enriched and nutrient-rich blood then returns to the fetus through one...
Development of Blood Vessels01:07

Development of Blood Vessels

The development of the vascular system in a fetus is a complex and intricate process that begins as early as 15 to 16 days post-conception. This process starts outside the embryo, specifically in the mesoderm of the yolk sac, chorion, and connecting stalk. Approximately two days later, the formation of blood vessels occurs within the embryo itself.
The initial formation of this system is facilitated by the small amount of yolk present in the ovum and yolk sac. Blood vessels originate from...
Autoregulation of Blood Flow01:17

Autoregulation of Blood Flow

Autoregulation mechanisms are characterized by their inherent capacity for self-regulation without necessitating specific nervous stimulation or endocrine control. These mechanisms facilitate the adjustment of blood flow and, therefore, perfusion specific to each tissue region. This self-regulation encompasses chemical signals and myogenic controls.
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation.