Reference values of fetal peak systolic blood flow Velocity in the middle cerebral artery at 12-41 weeks Of gestation in Jos, North Central, Nigeria
Objectives: The objectives of this prospective cross sectional study are (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 (ii) to correlate peak systolic velocity with gestational age and (iii) to establish regression prediction model of MCA-PSV for our population.
Patients and Methods Cross-sectional data were obtained from 480 low risk pregnant women and cross validated by 120 high risk pregnant women between 12 and 41 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. A comparison was made between the reference ranges produced in our study and those of Caucasians.
Results: Tables of mean values of peak systolic velocity and percentile with regression equations of MCA-PSV are resented, with suggested limits of 2.5th as lower borderline and 97.5th values representing the upper borderline of normal. Foetal middle cerebral artery peak systolic velocity demonstrated simple continues increase and strong positive correlation with gestational age. Calculated values of z were higher than critical values for PSV of subjects and Caucasian values;p<0.05
Conclusions: We have constructed reference ranges for MCA-PSV of gestation 1241week period and because the methodological flaws of published study have been eliminated, cross validated by a control group including larger sample size drawn from our population we therefore consider this to be useful for clinical practice.
Keywords:Infant mortality,Doppler ultrasound,peak systolic velocity,reference values,pregnancy