Early detection of congenital anomalies of the kidney and urinary tract: cross-sectional results of a community-based screening and referral study in China

Objective: To establish an effective screening model of congenital anomalies of the kidney and urinary tract (CAKUT) using ultrasound among neonates in Shanghai, China.

Design: Cross-sectional study.

Setting: A three-level screening model for CAKUT in neonates based on the child healthcare system was established since 2010 in Minhang District, Shanghai, China.

Participants: During 2010-2015, neonates with criteria such as preterm, low birth weight and so on were eligible to participate in the study. Cases with renal pelvis dilatation (RPD) and other abnormal renal findings were managed based on presumed strategies.

Main outcome measures: The proportion of RPD and other renal and urinary tract anomalies; number of diagnosed CAKUT under integrated management, especially obstructive uropathy. The anterior-posterior renal pelvic diameter (APRPD) cut-off points for likelihood of obstructive uropathy and need for surgery.

Results: A total of 8827 infants were consecutively screened. Absolute and relative rates of different degrees of RPD classified by APRPD were: mild (5-9.9 mm), 984 (11.1%); moderate (10-14.9 mm), 176 (2.0%); severe (≥15 mm), 20 (0.2%). Of 639 followed cases with RPD, 11 were diagnosed as obstructive uropathies. Of these, nine patients underwent surgery, at median age 2 months. A total 85.4% of mild, 62.5% of moderate and 30.0% of severe RPD cases resolved spontaneously. Other renal and urinary morphological abnormalities were diagnosed in 15 (0.2%) patients. The APRPD cut-off points for significant obstructive uropathy and need for surgery were 9.7 mm and 13.5 mm, respectively.

Conclusions: This three-level screening model is an effective and feasible strategy for early detection and intervention of CAKUT in the early postnatal period, especially for patients with high-grade RPD and other renal and urinary malformations. This strategy could be useful in China and other developing areas with limited medical resources.