Long-term renal and neurodevelopmental outcome in infants with LUTO, with and without fetal intervention.

Congenital lower urinary tract obstruction (LUTO) is a heterogeneous group of pathologies, the most common being posterior urethral valves (PUV) or urethral atresia. The bladder neck obstruction in utero leads to a spectrum of disease including mild oligohydramnios with normal renal function to a picture of severe oligohydramnios associated with chronic obstructive macro/microcystic renal parenchymal disease leading to chronic renal impairment. These anomalies may be isolated or complex; the latter being associated with other structural or chromosomal abnormalities. If isolated, the congenital bladder neck obstruction may be amenable to in-utero therapy. In a significant proportion of babies affected by LUTO there is severe oligohydramnios (occurring before 20 weeks gestation) and associated with pulmonary hypoplasia, a scenario almost always associated with perinatal death. For those babies that survive the perinatal period there is a significant risk of renal impairment, often necessitating renal dialysis or transplantation in childhood. In addition, there may be other morbidities such as chronic filling anomalies of the bladder that may require treatment.