Correlation between middle cerebral artery peak systolic velocity and fetal hemoglobin after 2 previous intrauterine transfusions

The middle cerebral artery peak systolic velocity (MCA-PSV) has been successfully used for timing the first 2 transfusions in fetuses at risk for anemia because of maternal red cell alloimmunization. The objective of this study was to assess whether the correlation between the MCA-PSV and fetal hemoglobin is maintained in fetuses that had undergone 2 previous intrauterine transfusions. Doppler measurement of MCA-PSV was performed before cordocentesis in 39 fetuses. The timing of the third transfusion was based on traditional criteria. The values of MCA-PSV and hemoglobin were expressed as multiples of the median (MoM). Anemia was defined as mild (hemoglobin