Objective: To determine the clinical outcome of isoimmunized pregnancies managed by middle cerebral artery peak systolic velocity (MCA-PSV) in an intention-to-treat study.
Method: Rhesus isoimmunized pregnancies were managed with serial ultrasound and Doppler studies at 7-day intervals up to 34 weeks of gestation, between 2001 and 2005. Invasive diagnostic and therapeutic procedures were carried out when MCA-PSV was indicative of moderate or severe anemia.
Results: The overall sensitivity in detecting moderate to severe fetal anemia at less than 34 weeks was 100% (95% confidence interval, 54.1-100.0 L). Twenty-two cases were managed with MCA-PSV. Twelve cases needed fetal blood sampling and 6 cases needed intrauterine transfusion. Cordocentesis revealed a hematocrit of more than 26% in 6 fetuses.
Conclusion: Management by MCA-PSV Doppler at weekly intervals is a highly sensitive method for detecting fetal anemia. It reduces the number of fetal blood samples needed and significantly lowers interventional procedures.