Background: The Doppler measurement of middle cerebral artery peak systolic velocity (MCA-PSV) is considered the gold standard for the noninvasive detection of moderate to severe anemia. However, the accuracy of this test has not been evaluated so far, specifically beyond 34 weeks.
Objectives: To assess the accuracy of MCA-PSV to detect moderate to severe fetal anemia and to identify risk factors associated with false-positive and false-negative MCA-PSV values after 34 weeks.
Study design: We studied a retrospective cohort of 150 pregnant women with severe alloimmunization who delivered between 2010 and 2014 and correlated MCA-PSV and fetal or neonatal hemoglobin levels.
Results: Sensitivity to predict severe anemia was 69%, with a false-negative rate of 3.6%. When MCA Doppler assessment was normal, the identification of serosal effusions increased the detection rate of severe fetal anemia to 94%, with a false-negative rate of 0.8%. False-positive MCA-PSV measurements were more frequent in fetuses with 1 previous intrauterine transfusion (p = 0.0002), but were not associated with MCA resistance index, intrauterine growth restriction and fetal heart rate.
Conclusions: Between 34 and 37 weeks, sensitivity of MCA-PSV Doppler assessment alone is 69% and increases to 94% when also considering signs of hydrops. False-positive MCA-PSV measurements are more frequent in case of former fetal transfusion.
Keywords: Alloimmunization; Anemia; Doppler ultrasound; Doppler velocimetry; Fetal transfusion; Intrauterine transfusion; Middle cerebral artery Doppler assessment.
© 2017 S. Karger AG, Basel.