Angle correction can be used to measure peak systolic velocity in the fetal middle cerebral artery.

Abstract

The objective of the study was to compare Doppler ultrasound measurements of the fetal middle cerebral artery peak systolic velocity (MCA-PSV) obtained at a 0 degrees angle of insonation to assessment at 30 degrees and 30 degrees with angle correction. Patients between 14 and 36 weeks' gestation were enrolled (n = 66). MCA-PSV measurements were assessed at 0 degrees , 30 degrees , and 30 degrees with angle correction. The data were analyzed using a mixed model adjusted for gestational age. Pairwise comparisons of mean MCA-PSV measurements were made using the Tukey multiple comparison test. All measurements were obtained for 50 fetuses (76%). Mean MCA-PSV measurements were statistically different between 0 degrees vs 30 degrees (P = .03 to < .001) but not between 0 degrees vs 30 degrees with angle correction (P = .34-.99) at each of the 5 gestational age groupings. Assessment of the MCA-PSV at 0 degrees and 30 degrees with angle correction provides comparable measurements during the second and third trimester of pregnancy.