Posterior Urethra Valve (PUV)/ Bladder Outlet Obstruction

At 20 weeks we were told our son had NO amniotic fluid and his kidneys and bladder and urethers (hope I spelled that right) are full of urine and dilated due to PUV. Because of the amount of fluid he is a severe case. We cant make out any images on ultrasounds due to lack of fluid. Has this been the case for any other parents here where there was NO fluid, not low fluid, at 20 weeks with a total blockage? If so, how long did you carry before you delivered and what was the outcome of your pregnancy/delivery/birth/child?