Objective A high-quality multi-centre randomised controlled trial (RCT) with the following objectives:

Primary objective

• ▶ To determine if intrauterine vesico-amniotic shunting for fetal bladder outflow obstruction, compared to conservative, non-interventional care improves pre-natal and perinatal mortality and renal function.

Secondary objectives

• ▶ To determine if shunting for fetal bladder outflow obstruction improves perinatal morbidity.

• ▶ To determine the safety and long-term efficacy of shunting.

Methods All pregnancies where there was a singleton, male fetus with ultrasound evidence of lower urinary tract obstruction and no other major congenital or structural anomalies were eligible. Following an initial ultrasound diagnosis of fetal bladder outflow obstruction, eligibility and baseline characteristics were confirmed including standard assessments of renal function, a detailed ultrasound examination to exclude other co-existing anomalies (and ideally fetal karyotyping). Following consent the fetus was randomized to receive either a fetal vesico-amniotic shunt or continue with conservative management without a shunt. The primary outcome measures were perinatal mortality and serum creatinine at 6 weeks of age. Long-term follow-up of continence and assessment of childhood development and quality of life is planned at 5 years.

Results 31 women have been randomised, 43 registered and 68 have had a termination of pregnancy. Completion of follow-up and analysis of primary outcome data will be complete by May 2011 and presented. These data will be compared with previously published data from systematic review and meta-analysis.

PLUTO is an international RCT funded by Wellbeing of Women and the HTA.