Study On The Association Of Fetal Thalassemia With The Middle Cerebral Artery Blood Flow Velocity

Objective:To investigate the association between the middle cerebral artery (MCA)blood flow velocity and fetal thalassemia.Methods:146 singleton pregnancies at risk due to fetal thalassemia,at 19-30 weeks' gestation,were performed with two-dimensional ultrasound and Doppler imaging.The MCA peak systolic velocity(PSV),mean velocity(Vmean), pulsatility index(PI)were measured.All fetuses were detected thalassemia genotypes by amniocentesis or cordocentesis.Hemoglobin determination was performed after cordocentesis.There are 109 thalassemia fetuses and 37 normal fetuses in this study.Among these thalassemia fetuses,20 had Hemoglobin Bart's Hydrops Fetalis Syndrome,5 had Hemoglobin H disease,38 hadα-thalassemia Trait,12 hadβ-thalassemia Major orβ-thalassemia Intermedia,34 hadβ-thalassemia Minor.Both MCA-PSV and Hemoglobin concentration were expressed as multiples of the median(MOM).These values on reference ranges had been established by Mari.The optimal threshold values for MCA-PSV were 1.29 times the median for fetal anemia.Fetal anemia was defined as hemoglobin concentration less than 0.84 times the median.Results:MCA-PSV,PI increased with increasing gestational age in All fetuses.The group of fetuses with Hemoglobin Bart's Hydrops Fetalis Syndrome had significantly higher MCA-PSV,Vmean compared to the other groups(P＜0.001);However,there were no statistical significant difference in the MCA-PSV,Vmean between the other groups(P＞0.05).There was no statistical significant difference in the MCA-PI between each group(P＞0.05) MCA-PSV＞1.29 MOM is better than cardiothoracic ratio in the prediction of Hemoglobin Bart's Hydrops Fetalis Syndrome(P＜0.05).All 5 fetuses with Hemoglobin Bart's Hydrops Fetalis Syndrome were confirmed severely anemic fetuses with a hemoglobin concentration＜0.55 MoM.Conclusion:Middle cerebral artery peak systolic velocity by Doppler ultrasound can be used to be a noninvasive tool to predict Hemoglobin Bart's Hydrops Fetalis Syndrome.Middle cerebral artery peak systolic velocity is a accurate parameter for the prediction of fetal anemia.Doppler evaluation of MCA-PSV is better than two-dimensional ultrasound in the prediction of Hemoglobin Bart's Hydrops Fetalis Syndrome.