GSTM1 and anemia: Accordingly, MCA-PSV is more commonly used, currently, as a non-invasive method in the assessment of fetal anemia in clinical practice [25], especially in the evaluation of Rh alloimmunization, fetal Hb Bart’s disease, parvovirus B19, etc. In addition to increased MCA-PSV, this study provides evidence that there was also a decrease in MCA-PI or an increase in end diastolic flow, probably caused by autoregulation to increase cerebral circulation in response to anemic hypoxia.