title: [Doppler velocimetry of the aorta in materno-fetal blood incompatibility].
abstract: The underlying pathogenesis of erythroblastosis fetalis is hemolysis of fetal red blood cells mediated by maternal antibodies. The resulting destruction of erythrocytes leads to progressive fetal anemia, and a hypervolemic condition develops in the fetus. The amount of maternal antibodies, real-time ultrasound, amniocentesis and/or cordocentesis can all be used to evaluate the degree of fetal anemia. The work presented here attempts to show that Doppler ultrasound can be used to detect the hypervolemic condition of anemic fetuses. One hundred fifty Doppler examinations were carried out on the aorta in 37 fetuses to evaluate the blood flow velocities and compare these with the fetal hematocrit. For the Doppler analysis, along with bidimensional echography, a Kranzbühler duplex scanner was used. In addition to the usual indices, the ratio of the median velocity to the maximum systolic velocity and an index of resistance using the maximum velocities 1/2 and 2/3 of the way through the cardiac cycle were calculated. Our examinations showed a significant increase in the temporal average of spatial average velocities (TASAV) and in the temporal average of maximum velocities (TAMV or M). The appearance of a spectral window was characteristic and a dicrotism in the curve was often observed. Much experience with the Doppler technique as well as a knowledge of factors influencing the blood flow velocity (caffeine, theine, nicotine, beta-sympathicomimetics) are necessary before attempting an interpretation of Doppler ultrasound results. Although the use of Doppler ultrasound does not yet permit a reduction in the number of invasive examinations, it does allow an improvement in the quality of surveillance of the fetal condition.
authors.affiliation: Département de Gynécologie-Obstétrique, Hôpital de Zurich.
authors.forename: Y
authors.initials: Y
authors.lastname: Favre
authors.forename: K
authors.initials: K
authors.lastname: Vetter
authors.forename: R
authors.initials: R
authors.lastname: Huch
authors.forename: A
authors.initials: A
authors.lastname: Huch
mesh_terms: D001011:Aorta; D001783:Blood Flow Velocity; D001787:Blood Group Incompatibility / Q000503:physiopathology; D004899:Erythroblastosis, Fetal / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D014463:Ultrasonography
vernacular_title: Vélocimétrie Doppler de l'aorte lors d'incompatibilité sanguine materno-foetale.