Abstract:

Objective To investingate the predictive value of a grading system based on the anteroposterior diameter of the renal pelvis (APD) combined with renal cortex thickness (RCT) for fetal renal pelvis dilation and neonatal renal function. Methods A retrospective study was conducted on 186 fetuses diagnosed with renal pelvis dilation by prenatal ultrasound at Qinhuangdao Maternal and Child Health Hospital. Based on postpartum follow-up, they were divided into the normal renal function group (n=146) and the abnormal renal function group (n=40). Logistic regression was used to analyze risk factors, and a combined APD-RCT grading standard was established. The predictive efficacy and consistency were evaluated using ROC curves and Kappa test. Results There were significantly higher APD, higher proportion of renal parenchyma echo enhancement, bladder wall thickening and oligohydramnios, while RCT was significantly lower in the abnormal renal function group (P<0.05). Multivariate Logistic regression analysis showed that increased APD, decreased RCT, renal parenchyma echo enhancement, bladder wall thickening and oligohydramnios were independent risk factors for abnormal renal function [OR(95%CI): 2.369 (1.753-3.204), 0.734 (0.557-0.968), 3.394 (1.696-6.793), 2.089 (1.344-3.247), 2.774 (1.938-3.971), respectively]. With the increase of APD-RCT grade (from I to IV), the rate of renal dysfunction increased progressively (2.6%, 10.5%, 40.0%, 92.9%, P<0.01). ROC analysis showed that the APD-RCT grading system predicted abnormal renal function with an AUC of 0.922. The weighted Kappa value was 0.86, indicating high consistency. Conclusion The combined APD-RCT grading system can effectively predict neonatal renal function abnormality in fetuses with renal pelvis dilation and demonstrate good clinical application value.

Key words: pyelectasis, kidney function tests, ultrasonography, prenatal, anteroposterior diameter of renal pelvis, renal cortex thickness