Donald School Journal of Ultrasound in Obstetrics and Gynecology

Register      Login

VOLUME 3 , ISSUE 3 ( July-September, 2009 ) > List of Articles


Fetal Aortic-cerebral Doppler Resistance Index Ratio: An Indicator of Physiologic Blood Flow Distribution

Zoltán Tóth, János Aranyosi, Tamás Deli, Péter Bettembuk, Bence Kozma, Tamás Kovács, Olga Török

Keywords : Fetal blood flow,descending aorta,middle cerebral artery,Doppler index ratio

Citation Information : Tóth Z, Aranyosi J, Deli T, Bettembuk P, Kozma B, Kovács T, Török O. Fetal Aortic-cerebral Doppler Resistance Index Ratio: An Indicator of Physiologic Blood Flow Distribution. Donald School J Ultrasound Obstet Gynecol 2009; 3 (3):91-96.

DOI: 10.5005/jp-journals-10009-1025

License: CC BY-NC 4.0

Published Online: 01-06-2010

Copyright Statement:  Copyright © 2009; The Author(s).



To interpret the physiologic fetal arterial blood flow distribution by relating the vascular impedance of the fetal descending aorta (DA) and middle cerebral artery (MCA) and to establish the reference ranges for the aortic-cerebral Doppler resistance index ratio (ACRI).

Study design

Ninety-six patients with uncomplicated pregnancies were recruited for the cross-sectional assessment of the Doppler resistance index (RI) in the fetal DA and MCA between the 38rd and 40th weeks of gestation. The normal ranges of the ACRI were calculated. A cut-off value was designed to facilitate the clinical application of the ACRI.


Between the 38th and 40th weeks of gestation in normal pregnancies the ACRI of healthy fetuses is constant, the overall mean is: 1.062 (+/– 0.087). A single cut-off value of 1.2 is recommended to assist separating normal and pathologic arterial blood flow patterns.


The normal ACRI reflects the identical vascular resistance of the descending aorta and the cerebral vessels, which maintains the physiologic fetal central arterial blood flow. Additional clinical studies are necessary to assess the diagnostic efficacy of the abnormal ACRI (>1.2) as a potentially useful marker of the centralized arterial circulation indicating the early stage of fetal hypoxemic jeopardy.

PDF Share
  1. Fetal nutrition and cardiovascular disease in adult life. Lancet 1993;341:938-41.
  2. Doppler ultrasound for fetal assessment in high risk pregnancies. Cochrane Database Syst Rev 2000;(2):CD000073.
  3. Blood flow to fetal organs as a function of arterial oxygen content. Am J Obstet Gynecol 1979;135:637-46.
  4. Do we now understand the control of fetal circulation? Eur J Obstet Gynecol Reprod Biol 1997;75:55-61.
  5. The “brain-sparing” effect: Antenatal cerebral Doppler findings in relation to neurologic outcome in very preterm infants. Am J Obstet Gynecol 1993;169:169-75.
  6. Cerebral-Umbilical Doppler Ratio As a Predictor of Adverse Perinatal Outcome. Obstet Gynecol 1992;79:416-20.
  7. Fetal arterial Doppler-IUGR and hypoxia. Eur J Obstet Gynecol Reprod Biol 1997;75:51-53.
  8. Doppler measurement of fetal and uteroplacental circulations: Relationship with umbilical venous gases measured at cordocentesis. Am J Obstet Gynecol 1990;162:115-20.
  9. Application cliniques de l'examen Doppler transcutane. In Velocimetrie Ultrasonore Doppler (Perroneau P. ed.), Seminaire INSERM, Paris 1974;213-40.
  10. Normal values of pulsatility index from fetal vessels: A cross sectional study on 1556 healty fetuses. J Perinat Med 1990;18:165-72.
  11. Fetal blood velocity waveforms in normal pregnancies. A longitudinal study. Acta Obstet Gynecol Scand 1989;68(2):171-78.
  12. Longitudinal Doppler ultrasonographic assessment of alterations in regional vascular resistance of arteries in normal and growth-retarded fetuses. Gynecol Obstet Invest 1995;39:171-79.
  13. Fetal venous, intracardiac, and arterial blood flow measurements in intrauterine growth retardation: Relationship with fetal blood gases. Am J Obstet Gynecol 1995;173:10-15.
  14. Doppler colour flow imaging of fetal intracerebral arteries and umbilical artery in the small for gestational age fetus. Br J Obstet Gynaecol 1995;102:174.
  15. Assessment of fetal compromise by doppler ultrasound investigation of the fetal circulation arterial, intracardiac, and venous blood flow velocity studies. Circulation 1995;91:129-38.
  16. Fetal arterial redistribution indicating true umbilical cord knot. Eur J Obstet Gynecol Reprod Biol Feb 2003;10;106(2):225-26.
  17. Antenatal Doppler measurements and early brain injury in very low birth weight infants. J Pediatr 2007;150(1):51-56.
  18. Normative values of Doppler velocimetry of five major fetal arteries as determined by color power angiography. Acta Obstet Gynecol Scand 2005;84(3):230-37.
  19. Fetomaternal Doppler sonography nomograms. Clin Exp Obstet Gynecol 2003;30(4):211-16.
  20. Fetal arterial and venous Doppler pulsatility index and time averaged velocity ranges. Prenat Diagn Dec 2007;27(13):1251-57.
  21. New Doppler index for prediction of perinatal brain damage in growth-restricted and hypoxic fetuses. Ultrasound Obstet Gynecol Sep 2007;30(3):303-11.
  22. A combination of umbilical artery PI and normalized blood flow volume in the umbilical vein: Venous-arterial index for the prediction of fetal outcome. Eur J Obstet Gynecol Reprod Biol Feb 2009;142(2):129-33.
  23. Effects of different sampling points on evaluation of fetal descending aortic flow. Osaka City Med J Jun 2006;52(1):39-45.
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.