Doppler measurements of blood flow in the middle cerebral artery for the diagnosis of fetal anemia

OBJECTIVES: This paper presents a possibility of non-invasive diagnosis of fetal anemia based on the Doppler assessing of peak systolic velocity (PSV) in the fetal middle cerebral artery. The results of Doppler measurements were compared with fetal peripheral blood count estimated after cordocentesis. MATERIALS AND METHODS: Doppler measurements of blood flow velocity in the fetal middle cerebral artery were performed in years 2000 and 2001 in 22 pregnancies complicated by maternal blood group alloimmunisation. Gestation age varied from 27 to 36 weeks, the mean gestation age was 32 weeks. Depending on hemoglobin concentration in the fetal blood sample the severity of anemia was divided into three groups: severe anemia (Hb = 12 g%). The results were statistically analyzed to estimate correlation between the Doppler blood flow indexes (PI, RI, SD and PSV) in the middle cerebral artery and the peripheral blood count (Hb, Ht, erythrocyte count) of fetal blood received by cordocentesis. Using T-Student-test the differences of average maximal blood flow velocities and mean Doppler indexes in the group of fetuses with severe anemia (Hb 12 g%) were compared. RESULTS: Highest (negative) correlation was found between the peak systolic velocity and the fetal hemoglobin concentration. The correlation index was -0, 85, which means the higher the peak systolic velocity the lower the hemoglobin concentration. The difference between the mean peak systolic velocity in the group of fetuses with severe anemia and the group without anemia was statistically significant (p 12 g%). CONCLUSIONS: Doppler ultrasonography with the measurement of peak systolic velocity in the middle cerebral artery is a good method in evaluating of fetal peripheral blood count. Non-invasive peak systolic velocity measurements in the middle cerebral artery allow to assess the fetal hemoglobin concentration and also to reduce the count of diagnostic cordocentesis.