Noninvasive diagnosis of fetal anemia in RH-alloimmunized pregnancies by color Doppler

摘要

Introduction. Fetal anemia is usually diagnosed by invasive procedures, such as amniocentesis and cordocentesis. As these procedures carry a substantial risk for pregnancy loss, a nonivasive method for diagnosing fetal anemia is needed. Doppler allows measurement of blood flow velocity in fetal vessels. In anemic fetuses increased velocities in medial cerebral artery (MCA) are registered. The aim of our study was to evaluate if there were changes in blood flow waveforms in anemic fetuses' MCA, and if these changes correlated with values of fetal hematological parameters. Material and methods. A clinical study evaluated 172 pregnancies of gestational age between 28 and 32 weeks, in which cordocentesis was performed due to maternal Rh-alloimmunization. During sonographic examination we evaluated blood flow velocities and pulsatility index (Pi) in MCA. We registered hematological parameters such as hemoglobin and hematocrit. Based on hemoglobin levels, all fetuses were divided into four groups: nonanemic (140 g/l); mild anemia (120-139.9 g/l); moderate anemia (100-119.9 g/l) and severe anemia requiring intrauterine transfusion (99.9 g/l). We compared mean systolic velocities and Pi between groups and studied the correlation between MCA mean systolic velocities and hemoglobin and hematocrit values. Statistical analysis was done using AN OVA test and parameter linear correlation. The difference was considered to be significant if p