Efficacy of renal ultrasound screening among 4-month-old infants in Sammu City for detecting congenital abnormalities of the kidney and urinary tract

Abstract

Renal ultrasound screening was performed on 1018 apparently healthy 4-month-old infants in Sammu City to detect congenital abnormalities of the kidney and urinary tract (CAKUT). Ultrasound findings included hydronephrosis greater than grade 3 by the Society for Fetal Urology classification, and grade 2 with apparent or fluctuating renal calyceal dilatation, a renal length less than 42 mm, and a renal length discrepancy greater than 8 mm. Twenty-three infants (2.3%) had positive ultrasound findings and were referred to hospital. Of these, 11 (1.1%) had hydronephrosis, 5 with grade 3 and 6 with grade 2, respectively. Seven infants (0.69%) had a renal length less than 42 mm. Finally, 7 infants with CAKUT (0.69%) were identified. Bilateral grade III and IV vesicoureteral reflux (VUR) with small kidney requiring surgery, pelviureteric junction obstruction, and megaureter with ureterocele were detected in 3 infants with grade 3 hydronephrosis and renal length discrepancy. Bilateral grade IV VUR was detected in 1 infant with grade 2 hydronephrosis with fluctuating pyelocalyceal dilatation. Ultrasound was effective for the early detection of CAKUT. Clear criteria for positive ultrasound findings without excessive screening of hydronephrosis would enable renal ultrasound screening by general pediatricians and medical technologists, reduce first positive screening rate, and improve medical cost-benefits.