Fetal urinary tract obstruction: Fetal cystoscopy

Introduction: Congenital anomalies of the urinary tract are relatively common, affecting approximately 1:500 pregnancies in which obstructive uropathies account for the majority of cases [1–4]. Obstruction may be at different levels, at the ureteropelvic junction (upper level) or ureterovesical junction (mid level) or urethral (lower level). The upper and mid urinary tract obstructions may be unilateral or bilateral with different consequences depending on the laterality. When the obstruction is bilateral or at the level of urethra (bladder outflow obstruction known as lower urinary tract obstruction or LUTO), the perinatal prognosis is poor due to the consequences of reduced fetal micturition and urine retention, leading to severe oligohydramnios and renal damage [1–3]. According to a British study, LUTO affected 2.2 cases in 10 000 births in a northern region of England between 1984 and 1997 [5]. Despite the low incidence, LUTO has the greatest impact on perinatal and child health among the congenital uropathies [6]. The natural history of LUTO is dependent on the degree of bladder outflow obstruction (complete or partial) and gestational age at presentation. These two factors may be inter-related since complete bladder obstruction is associated with earlier manifestations of the obstructive uropathy.