Marcos Roberto Taveira

Transfusão Intra-uterina na Isoimunização Materna pelo Fator Rh

Purpose: to evaluate the intrauterine treatment of anemic fetuses that underwent intrauterine transfusions due to rhesus isoimmunization. Methods: the authors studied sixty-one fetuses undergoing intrauterine transfusions by the intravascular, intraperitoneal or both routes. The hydropic fetuses (19.7%) received only intravascular intrauterine transfusions. There was an overall number of 163 intrauterine transfusions with a mean of 2.7 procedures for each case. The indications for intrauterine transfusions were high values of bilirubin in amniotic fluid analyses by the Liley method or a hemoglobin concentration of cord blood below 10.0 g/mL. Results: the overall perinatal survival rate was 46% for hydropic fetuses and 84% for the nonhydropic ones. There were no maternal side effects related to the procedures. Half of the intrauterine transfusions were performed by the intravascular route. The mean gestational age at the delivery was 34.8 weeks. Conclusions: despite better perinatal results with intrauterine transfusions guided by ultrasound, especially using intravascular procedures, rhesus isoimmunization remains as an important cause of high rates of perinatal morbidity and mortality.

Avaliação da Velocidade Média na Aorta Torácica Descendente em Fetos com Anemia

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.

Assessment of the Correlation Between Hemoglobin Concentration and the Echographic Measurement of Biventricular Outer Diameter in Anemic Fetuses of Isoimmunized Women

OBJECTIVE To assess whether a significant correlation exists between the echographic measurement of biventricular outer diameter and the pretransfusional serum concentration of fetal hemoglobin and whether that echographic measurement can be used as a noninvasive marker of fetal anemia. METHODS A prospective cross-sectional study was carried out comprising 65 cordocenteses performed in 36 anemic fetuses of mothers with isoimmunization to the Rh antigen. The biventricular outer diameter (BOD) was obtained by M-mode evaluation. Previous to the transfusion, a 0.5-mL fetal blood sample was obtained for hemoglobin measurement with spectrophotometry in the Hemocue device. The minimum square regression was used with p < 0.05 and multivariate analysis were used as statistical analysis. RESULTS An inverse correlation was observed between the fetal hemoglobin concentration before transfusion and the BOD measurement, and a direct correlation was observed between the BOD measurement and gestational age. In addition, multivariate analysis showed that fetal hemoglobin concentration decreases as BOD increases, independently of the influence of gestational age on that parameter. CONCLUSION An inverse correlation exists between fetal hemoglobin concentration and BOD measurement, regardless of gestational age. The findings suggest that BOD may become an echographic predictor of the hemoglobin level of fetuses of isoimmunized pregnant women.

Diagnóstico não invasivo da anemia fetal pela medida do pico de velocidade sistólica na dopplervelocimetria da artéria cerebral média

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 c2 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.