Related Experiment Video
Updated: Jul 31, 2026
08:04
Murine Fetal Echocardiography
Published on: February 15, 2013
Left ventricular hemodynamics in anemic fetal lambs
M D Kilby1, R Szwarc, L N Benson
1Academic Department of Obstetrics & Gynaecology, University of Toronto, Canada.
Journal of Perinatal Medicine
|May 22, 1998
Summary
Fetal anemia significantly increases left ventricular (LV) stroke volume by reducing afterload, not affecting preload or contractility. This study reveals how fetal lambs compensate for anemia, offering insights into cardiovascular adaptation.
Area of Science:
- Fetal Physiology
- Cardiovascular Research
- Anemia Studies
Background:
- Fetal lambs were studied to understand cardiac output determinants.
- Anemia is a condition affecting oxygen transport and cardiovascular function.
Purpose of the Study:
- To assess left ventricular (LV) determinants of cardiac output in fetal lambs.
- To compare anemic fetal lambs with non-anemic controls.
Main Methods:
- 12 instrumented fetal lambs were used, with 6 developing induced isovolemic anemia.
- Left ventricular (LV) volumes and pressures were measured using a conductance catheter.
- Data were collected prospectively at 131-134 days of gestation.
Main Results:
- Anemic fetuses showed decreased hematocrit and oxygen content but similar blood gases, heart rate, preload, and mean arterial pressure.
- LV stroke volume increased by 75% in anemic fetuses due to a 61% decrease in LV afterload.
- LV contractility and relaxation showed no significant changes, though contractility approached statistical significance.
Conclusions:
- This study provides the first absolute LV volumes in anemic ovine fetuses.
- The observed increase in LV stroke volume is primarily attributed to decreased afterload.
- The model successfully replicated moderate, non-hydropic, isovolemic fetal anemia.
