Z-score reference ranges of normal fetal middle cerebral artery peak systolic velocity / 中华超声影像学杂志

ABSTRACT

Objective:To construct Z-score ranges for normal fetal middle cerebral artery peak systolic velocity(MCA-PSV).Methods:From May 2017 to October 2019, 865 normal singleton fetuses of 10th to 40th gestational weeks underwent prenatal ultrasound in the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region. Using fetal biometric parameters as independent variables, and measurement of MCA-PSV on standard section as dependent variables, the regression analyses of the mean(M) and the standard deviation(SD) for each parameter were calculated separately and then the best fitting equation was selected. A group of diseases which might cause the abnormal MCA-PSV were assessed using these standards.Results:①Strong correlations were found between MCA-PSV and fetal biometric parameters ( r=0.935-0.939, P<0.001). ②Quadratic or cubic regression equations were fitted to the models of the means of the MCA-PSV, whereas linear equations were fitted to the SDs. ③In these case groups, intrauterine growth restriction, severe preeclampsia, intrauterine infection and homozygous α-thalassemia-1 demonstrated Z-score>2 reflective of increased MCA-PSV with varying degrees, especially with the homozygous α-thalassemia-1 fetus being the most significant (17/20, 85%). Conclusions:The calculation of Z-score for MCA-PSV as a function of fetal biometric parameters is intuitive and simple, it can be used as an important indicator especially for homozygous α-thalassemia-1.