Z-scores analysis of kidney volume in normal fetuses in second and third trimester
10.3760/cma.j.cn131148-20200109-00019
- VernacularTitle:孕中晚期正常胎儿双肾体积Z-评分研究
- Author:
Ying JIN
1
;
Ran XU
;
Qichang ZHOU
;
Yan DENG
;
Jiawei ZHOU
;
Shi ZENG
Author Information
1. 中南大学湘雅二医院超声科，长沙 410011
- From:
Chinese Journal of Ultrasonography
2020;29(6):483-488
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the variation of renal volume with gestational age(GA), biparietal diameter(BPD), abdominal circumference(AC), femur length (FL) and the Z value calculation formula.Methods:Five hundred and eighty singleton pregnancy women from 20th to 38th gestational weeks in Second Xiangya Hospital of Central South University were enrolled. Two dimensional ultrasound was performed to record fetal growth parameters and renal longitudinal, transverse, anteroposterior diameters. Renal volume was calculated using ellipsoid volume equation: Volume =6/π×length×width×thickness. Using GA, BPD, AC, FL as independent variables and renal volume as dependent variables, the regression analyses of the mean and the standard deviation(SD) for each parameter were calculated separately. The Z-scores were calculated by the formula: Z-scores=(actual measurements of renal volume-predictive value of renal volume)/SD of predictive value.Results:Five hundred and forty-three cases of normal singleton fetuses were involved.The left and right renal volume were increased along with GA, BPD, AC, FL. Quadratic polynomial regression equations were each fitted to the models( r=0.775, 0.771, 0.811, 0.738, P<0.001; r=0.747, 0.735, 0.754, 0.745, P<0.001, respectively). The SD increased with the increases of independent variables and could be modeled with a simple linear regression( r=0.146, 0.225, 0.071, 0.155, P<0.001; r=0.091, 0.157, 0.091, 0.123, P<0.001, respectively). Z-scores were calculated and proved normally distributed after Shapiro-Wilk test( P>0.05). Conclusions:The normal Z-score reference range of fetal renal volume is established to help assess the normal renal growth and identify fetal renal abnormalities.
