Blood flow and oxygen delivery to fetal organs as functions of fetal hematocrit

Fred D. Fumia, Daniel I. Edelstone, Ian R. Holzman

Research output: Contribution to journalArticlepeer-review

71 Scopus citations


The purpose of our experiments was to relate blood flow and oxygen delivery (blood flow × arterial blood oxygen concentration) to fetal organs as functions of fetal hematocrit. In 12 chronically catheterized fetal lambs, we observed two patterns of responses of fetal organs and tissues to isovolemic alterations in fetal hematocrit from 12% to 55%. In group 1 organs (brain, heart, adrenal glands), blood flows increased as hematocrit was either raised or lowered from normal such that oxygen delivery to these organs was stable over the entire range of hematocrits studied. In group 2 organs (gastrointestinal tract organs, spleen, kidneys, placenta, and carcass), blood flows varied little over the range of hematocrits from 12% to 40% or 45% but decreased at hematocrits ≥ 40% to 45%. Because of these flow responses, oxygen delivery to these organs and tissues was maximal at hematocrits ranging from 32% to 38%. Our data indicate that the various organs of the unanesthetized fetal lamb respond in different ways to alterations in hematocrit. It is of particular interest that, in the great majority of the organs of the fetus, oxygen delivery is maximal at hematocrits considered normal for the fetal lamb in utero.

Original languageEnglish
Pages (from-to)274-282
Number of pages9
JournalAmerican Journal of Obstetrics and Gynecology
Issue number3
StatePublished - 1984
Externally publishedYes


Dive into the research topics of 'Blood flow and oxygen delivery to fetal organs as functions of fetal hematocrit'. Together they form a unique fingerprint.

Cite this