Congenital lower urinary tract obstruction (LUTO) comprises a heterogeneous group of pathologies causing obstruction to the urethra, the most common being posterior urethral valves. Such pathology is often associated with high perinatal mortality and varying degrees of perinatal and infant morbidity. A high proportion of LUTO may be visualised during routine second trimester (and first trimester) ultrasound giving rise to the possibility of determining individual fetal prognosis and treatments such as vesico-amniotic shunting, with a view to altering pathogenesis. The aims of the percutaneous shunting in low urinary tract obstruction (PLUTO) trial are to determine the effectiveness of these treatments and accuracy of the investigations with the primary outcome measures being perinatal mortality and postnatal renal function.