Reference values of fetal peak systolic blood flow velocity in the middle cerebral artery at 19-40 weeks of gestation.
OBJECTIVE
The objectives of this prospective study were (i) to establish new reference values of peak systolic blood flow velocity measurement in the fetal middle cerebral artery (MCA-PSV) following validated methodological guidelines and (ii) to develop a method to calculate Z-scores of MCA-PSV.


METHODS
Cross-sectional data were obtained from 331 pregnant women between 19 and 40 weeks' gestation. Reference ranges for MCA-PSV were constructed and for each measurement linear regression models were fitted separately to the mean and standard deviations (SD) as a function of gestational age. An application to calculate Z-scores was developed. A comparison was made between the reference ranges produced in our study and those of a previous one.


RESULTS
A new chart, table of centiles and regression equations of MCA-PSV are presented. Comparison of our reference ranges with ones produced in a previous study showed similar 5th centile values. However, the values for the 50th and 95th centiles between 19 and 28 gestational weeks were lower in our study.


CONCLUSIONS
We have constructed reference ranges for MCA-PSV which, because they are derived from a larger number of examinations in the 15-20-week period and because the methodological flaws of the previously published study have been eliminated, we consider to be more accurate and therefore more useful for clinical practice.
Perinatal Research Unit, Department of Obstetrics, Zurich University Hospital, Frauenklinikstrasse 10, 8091 Zurich, Switzerland.
J
J
Kurmanavicius
A
A
Streicher
E M
EM
Wright
J
J
Wisser
R
R
Müller
P
P
Royston
R
R
Huch
A
A
Huch
R
R
Zimmermann
D001783:Blood Flow Velocity; D005260:Female; D005333:Fetus / Q000098:blood supply*; D005865:Gestational Age; D006801:Humans; D016014:Linear Models; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging* / Q000196:embryology; D011247:Pregnancy; D011446:Prospective Studies; D012016:Reference Values; D018615:Ultrasonography, Doppler, Color; D016216:Ultrasonography, Prenatal