Hello, * As per my clinical experience, the swollen kidney in fetus does indicate severe obstruction at distal pathway through which the kidney gets bigger and bigger. * The most common cause is pelvi ureteric junction ( PUJ ) obstruction, the part where kidney opens into the pelvis for drainage through cluster of glomeruli and nephrons. * As there is severe narrowing at the junction, the kidney swells enormously. * Second less common condition is vesicoureteric junction narrowing, where the ureter enters one side of the urinary bladder. However, this condition is associated with kinking of whole ureter. * There are particular interventions available in eary phases of the obstruction where there is mild to moderate hydronephrosis, but in advance stage , there is nothing to get much out of any intervention. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr. Bhagyesh V. Patel