P220: Middle cerebral artery peak systolic velocity in normal and high risk pregnancies: the impact of Doppler-gate-placement and correction of the angle of insonation

Abstract

and the Doppler-gate was placed at the origin of the MCA and in the distal, visualized part of the vessel. Measurements were performed with and without angle-correction and compared. We constructed new reference ranges for the PSV-values of the total population (N = 146) with angle correction. Results: There was a significant difference between the PSV-values at the proximal and the distal part of the MCA with higher velocities proximal. The measurements with angle correction also showed significantly higher velocities as those without. Between the normal and complicated pregnancies we couldn’t find a significant difference. Discussion: As we couldn’t show significant difference of the PSVACM between normal and complicated pregnancies the reference ranges can be applied also in complicated pregnancies. Our data show that placement and angle correction are relevant for a standardisized measurement, especially important because the decision for invasive testing for fetal anaemia depends on it.