Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(8):649-653
DOI 10.1590/S0100-72032004000800009
PURPOSE: to assess the correlation between middle cerebral artery peak systolic velocity and umbilical cord blood hemoglobin concentration and to determine its diagnostic value. PATIENTS AND METHODS: a cross-sectional prospective study was performed from January 2000 to May 2003. Forty-four isoimmunized pregnant women underwent a protocol for the identification of fetal hemolysis. When intrauterine transfusions were indicated, the umbilical cord blood hemoglobin concentration was measured at the beginning of the procedure. Each intrauterine transfusion preceded by Doppler velocimetry of the middle cerebral artery was regarded as one case, summing up eighty-three procedures. In all cases, the middle cerebral artery Doppler examinations were performed within the three hours preceding fetal blood sample collection. The systolic velocity peak was recorded and considered abnormal when its value was above 1.5 times the median for the corresponding gestational age. Hemocue® (B-Hemoglobin Photometer Hemocue AB; Angelholm, Sweden) was the device used to measure fetal hemoglobin concentration. The relationship between middle cerebral artery peak systolic velocity and cord blood hemoglobin was obtained by the chi2 test, considered significant at p<0.05. RESULTS: in thirty-three cases the cord blood hemoglobin concentration was below 10.0 g/dL. There was a strong correlation between the two measured variables (p<0.001). The middle cerebral artery peak systolic velocity with values above 1.5 times the median was associated with cord blood hemoglobin concentration below 10 g/mL (p<0,001). The sensitivity of an increased middle cerebral artery peak systolic velocity was 75.8% for the detection of a cord blood hemoglobin level of 10 g/dL or lower. CONCLUSION: the middle cerebral artery peak systolic velocity can be used as a noninvasive method for the diagnosis of fetal anemia.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(10):653-657
DOI 10.1590/S0100-72032001001000007
Purpose: to verify if there is an association between the mean blood velocity in the descending thoracic aorta and fetal anemia diagnosis. Methods: this is a prospective, cross-sectional study in which the mean blood velocities in the fetal aorta, in 66 fetuses at risk for severe anemia due to severe Rh immunization, and cord blood hemoglobin levels were analyzed comparatively. The hemoglobin level was obtained by cordocentesis if an intravascular transfusion was performed for severe anemia, however, if the fetus received an intrauterine transfusion by the intraperitoneal route or if the fetus did not receive a transfusion at all, hemoglobin level was measured at the time of pregnancy termination by umbilical cord puncture. The authors made a statistical association between the mean blood velocity in fetal descending thoracic aorta and the diagnosis of fetal anemia. The c² test was used for statistical analysis and a p value <0,05 was used to indicate significance. Results: there was a significant and indirect association between the mean blood velocity in the descending thoracic aorta and the detection of fetal anemia. The mean blood velocity in fetal thoracic aorta had a sensitivity of 47.4% for the diagnosis of moderate fetal anemia (Hg<10.0 g/dL), with a p value <0.01 by the Fisher exact test, and a sensitivity of 54.5% for severe Rh isoimmunization (Hg<7.0 g/dL), with a p value =0.01. Conclusion: this study revealed a significant indirect correlation between mean blood velocity in the descending thoracic aorta and the detection of fetal anemia due to Rh isoimmunization.