SHORT-TERM MATERNAL OXYGEN ADMINISTRATION IN FETUSES WITH ABSENCE OR REVERSAL OF END-DIASTOLIC VELOCITY IN UMBILICAL ARTERY - PATHOPHYSIOLOGICAL AND CLINICAL CONSIDERATIONS
L. Caforio et al., SHORT-TERM MATERNAL OXYGEN ADMINISTRATION IN FETUSES WITH ABSENCE OR REVERSAL OF END-DIASTOLIC VELOCITY IN UMBILICAL ARTERY - PATHOPHYSIOLOGICAL AND CLINICAL CONSIDERATIONS, Acta obstetricia et gynecologica Scandinavica, 77(7), 1998, pp. 707-711
Background. The aim of our study was to evaluate the hemodynamic respo
nse to acute maternal hyperoxygenation (O-2 test) in a group of growth
retarded fetuses with absence or reversal of end-diastolic velocity (
AREDV) in the umbilical artery (UA) and to correlate this response to
a series of fete-placental velocimetric parameters and clinical variab
les. Methods. In 25 singleton pregnancies, fete-maternal Doppler veloc
imetry was performed before and after acute maternal hyperoxygenation.
Results. Ten fetuses (40%) exhibited an increase of middle cerebral a
rtery Pulsatility Index (PI) >20% after O-2 (Responders), while in 15
fetuses PI did not change relevantly (Non-responders). Non-responder f
etuses showed a higher prevalence of reverse flow in umbilical artery
(6/15 vs 0/10; p<0.03) and a slight, but not significant, higher perce
ntage with reversed flow in inferior vena cava (% of A). Also the prev
alence of a % of A greater than 95(th) confidence interval was higher
in Non-responders (13/15 vs 4/10; p<0.04). Finally the Responder fetus
es showed higher peak velocities in the cardiac outflows, even if the
difference reached a statistical significance only for the pulmonary a
rtery. The outcome of the two groups did not differ significantly. Con
clusions. Our results seem to prove an ability of O-2 test in selectin
g a group of AREDV fetuses characterized by a higher degree of hemodyn
amic deterioration and hence 'placed' in a more advanced step of the p
athological process leading to overt cardiac decompensation, even if t
he clinical application of such a test seems to be still of limited va
lue.