Clinical perinatal urology

Abstract

In a large prospective Swedish study, the incidence of prenatally detected renal anomalies was 0.28 % in which two-thirds (0.18 %) were hydronephrosis. A British study, in which 99 % of the pregnant population in Stoke-on-Trent were scanned at 28 weeks’ gestation, demonstrated hydronephrosis prenatally in 1.40 % of cases, which was confirmed postnatally in 0.65 % [2]. Others have reported a 1–3% incidence of ANH [1–5]. These authors defined prenatal hydronephrosis as an anteroposterior (A-P) diameter of the renal pelvis greater than 5 mm but noted the lack of consensus on the definition of antenatal hydronephrosis [6–8]. With the rapid improvement of ultrasound technology, the incidence of detection of renal anomalies may be changing. In a more recent prospective cohort study (1999–2003), a 0.76 % incidence of urinary tract abnormalities was detected, which was increased as compared to an earlier cohort from the same institution (0.3 %, 1989–1993) [9]. Many variations in the definition and management of ANH exist in the literature and clinical practice, including method and frequency of in utero testing, radiographic documentation, classification, or postnatal management [10–16].