The effect of intravascular transfusion for rhesus haemolytic disease on umbilical artery Doppler flow velocity waveforms |
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| Authors: | KEVIN P. HANRETTY Research Fellow MARTIN J. WHITTLE Consultant Obstetrician DAVID H. GILMORE Lecturer MARGARET B. McNAY Honorary Lecturer CATHERINE A. HOWIE Statistician PETER C. RUBIN Professor |
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| Affiliation: | Departments of Midwifery and Materia Medica, University of Glasgow;Department of Therapeutics, University of Nottingham |
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| Abstract: | Summary. To test the hypothesis that an increase in fetal blood viscosity is associated with an increase in resistance to flow, the effect on Doppler flow velocity waveforms of percutaneous umbilical blood sampling and intravascular transfusion was studied in 20 patients undergoing a total of 35 procedures. All but four of the 22 transfusions were associated with a decrease in resistance to flow, as shown by a reduction in the umbilical artery systolic/diastolic ratio, and this also occurred on 10 of the 13 occasions when blood sampling only was performed. These findings suggest that acute changes in blood viscosity following intravascular transfusion arc not associated with an increase in resistance to flow as assessed by Doppler velocimetry. Umbilical blood sampling per se may be associated with a Immorally mediated reduction in placental vascular resistance to flow. |
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