Ultrasound screening of the kidneys and urinary tract in 11.887 newborn infants: A 10-year experience

Objective: To determine the usefulness of sonographic screening of the newborn kidneys and urinary tract over a 10-year time period. Methods: Ultrasound screening of the kidneys and the urinary tract was performed between the third and tenth day after birth on 11.887 newborn infants. The classification of renal pyelectasis (RPE) according to the Society for Fetal Urology (SFU) was used. We evaluated infant renal pathologies and correlated them with the gestational age and weight at birth. Results: Renal pyelectasis (grades 1-4) was detected in 179 cases (1.5%); it was significantly more common in male (vs female) infants (p < 0.001). One(vs two-) sided dilatation of the renal pelvis was more common, with the left side dominating (p < 0.05). Renal pyelectasis was occasionally associated with parenchymal and positional anomalies, such as nephrocalcinosis (0.27%), double kidneys (0.24%), horseshoe kidneys (0.11%), pelvic kidneys (0.08%), multicystic (0.07%) and polycystic (0.025%) kidneys. In infants with renal pyelectasis grade 4 (n = 36), gestational diabetes mellitus of the mother and birth weight > 4.000 g were the most significant risk factors (p < 0.01). Conclusions: Renal pyelectasis grades 1-4 was detected in only 1.5% of 11.887 consecutive infants subjected to sonographic screening of the kidneys and the urinary tract within the first 10 days after birth. Sonographic screening of the kidneys and the urinary tract is a non-invasive and effective screening method after birth. It allows planning for appropriate diagnostic tests and therapeutic procedures in a timely fashion.