Document Detail

Uterine flow velocity waveform shape as an indicator of maternal and placental development failure mechanisms: a model-based synthesizing approach.
MedLine Citation:
PMID:  8590189     Owner:  NLM     Status:  MEDLINE    
High pulsatility indices (PIs) and/or notches on the Doppler flow velocity waveforms of the uterine artery have been interpreted as indications of high placental flow impedance, and are known to be associated with poor fetal outcome. A software model of the uteroplacental blood path and its use to investigate possible interactions within the uteroplacental unit in more detail are described. Increasing transcotyledonary resistance to represent intervillous obstruction raised the cotyledonary core pressure and spiral artery PI. Increased spiral artery flow resistance, representing failed spiral artery invasion, reduced the cotyledonary core pressure and reduced the spiral artery PI. In vivo, such changes in cotyledonary core pressure would modify the transplacental water balance, promoting oligohydramnios for spiral artery invasion failure and polyhydramnios for villous obstruction. Both mechanisms increased the uterine and arcuate PI, but failed to produce a notch. It was found that notch formation depended on terms representing increased compliance (distensibility) of the uterine and/or arcuate artery walls, which have no direct effect on uteroplacental mean flow. The same mechanism steepened and increased uterine artery peak systolic flow, contributing to increased PI. The notch phenomenon seems to be an indicator of abnormal maternal artery wall status, independent of placental obstructive mechanisms, which can mask obstructive PI changes. Computer analysis of the frequency index profile should allow separation.
D G Talbert
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology     Volume:  6     ISSN:  0960-7692     ISO Abbreviation:  Ultrasound Obstet Gynecol     Publication Date:  1995 Oct 
Date Detail:
Created Date:  1996-03-28     Completed Date:  1996-03-28     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  9108340     Medline TA:  Ultrasound Obstet Gynecol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  261-71     Citation Subset:  IM    
Institute of Obstetrics and Gynaecology, Royal Postgraduate Medical School, Queen Charlotte's and Chelsea Hospital, London, UK.
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MeSH Terms
Computer Simulation*
Placental Circulation* / physiology
Ultrasonography, Doppler*
Ultrasonography, Prenatal*
Vascular Resistance
Comment In:
Ultrasound Obstet Gynecol. 1995 Oct;6(4):237-9   [PMID:  8590185 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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