Feasibility of Measuring 3‐Dimensional Renal Parenchymal Volume to Predict Postnatal Renal Function in Near‐Term Fetuses With Congenital Hydronephrosis

Objectives The purposes of this study were to evaluate the feasibility of predicting kidney function using the fetal renal parenchymal volume as determined by prenatal 3‐dimensional (3D) sonography and to determine the association among the prenatal renal pelvic diameter, renal parenchymal volume, and postnatal renal function in near‐term fetuses with unilateral hydronephrosis. Methods This retrospective study included 42 kidneys (21 normal and 21 hydronephrotic) from 21 fetuses between 30 and 39 weeks' gestation. We used the extended imaging virtual organ computer‐aided analysis (XI VOCAL; 10 planes) technique for the prenatal volumetric measurements, and postnatal renal function was estimated using renal scintigraphy. An independent‐samples Student ttest, Spearman's rank correlation, and simple linear regression were used for the statistical analyses. Reproducibility was confirmed with a paired Student t test and intraclass correlation coefficients. Results The renal pelvic diameter correlated well with the renal parenchymal volume Spearman ρ = 0.765; P < .001). The postnatal renal function correlated with the adjusted 3D renal parenchymal volume (Spearman ρ = −0.321; P = .043) but did not correlate with the prenatal renal pelvic diameter (Spearman ρ = −0.291; P = .062). Conclusions This preliminary study showed that 3D renal parenchymal volume could be a coparameter for predicting postnatal renal function with the renal pelvic diameter. Further studies in a larger population are required to obtain robust results.