The postnatal outcome and prognostic cut-off value of fetal pyelectasia

Choi, Jae Sung; Won, Hye Sung; Shin, Hye Jin; Kim, So Ra; Chung, Ji Youn; Lee, Pil Ryang; Lee, In Sik; Kim, Am

Abstract

OBJECTIVE
The purpose of our study was to evaluate the postnatal outcome of fetal pyelectasia and to assess the cut-off value for prediction of renal pathologic processes and surgical intervention.
MATERIALS AND METHODS
Seventy-seven cases of pyelectasia were identified during the study period (1996 through 2000). Fetuses with antero-posterior pelvic diameter (APPD) >or=7 mm after 28 weeks were included. Postnatal evaluation included renal sonogram, voiding cystourethrogram, and renal flow and function studies.
RESULTS
Renal pathologic processes after birth were found in 38 of 77 cases (49%). Ureteropelvic junction obstruction (19 cases, 50%) was the most common, followed by 4 cases of duplicated kidney, 3 cases of ureterovesical junction obstruction, 2 cases of primary vesicoureteral reflux, dysplastic kidney, extrarenal pelvis respectively and 1 case of ureterocele. Surgical intervention was performed in 21 cases (55%); pyeloplasty (13), nephrectomy (including partial) (3), transurethral incision of ureterocele (2), uretero- ureterostomy (1), uretero-cystostomy (2). Using cut-off value derived from receiver operating characteristic (ROC) curve, renal APPD >or=10.5 mm, >or=13.6 mm after 28 weeks gestation could predict the fetuses who would have renal pathologic processes and need surgical intervention, with sensitivity and specificity of 77.5%, 79.4% and 90.5%, 89.3%, respectively.
CONCLUSION
It is possible to predict the fetuses who would require appropriate urologic evaluation and surgical intervention after birth, with determining the renal pelvic diameter in the third trimester of pregnancy.