In current obstetrics practice what is the best test for monitoring sensitized Rh negative mother?

Best test for monitoring senstitized Rh negative mother isMiddle cerebral aery doppler wave forms Serial Doppler study of middle cerebral aery (MCA)-peak systolic velocity (PSV) is the mainstay to assess fetal anemia. A value >1.5 multiples of the median (MOMs) for the corresponding gestational age, predicts moderate to severe fetal anemia. This value (between 24 weeks and 35 weeks of gestation), is an indication for cordocentesis and fetal transfusion