Acute maternal obstructive renal failure in a twin gestation despite normal physiological pregnancy-induced urinary tract dilation.

Obstructive renal failure due to an overdistended uterus is a very rare complication of pregnancy. Most previously reported cases have involved twin gestations, the majority occurring in the presence of polyhydramnios. We describe a patient with a twin gestation who developed acute obstructive renal failure despite only very mild physiological pregnancy-induced dilation of the urinary collecting system in the absence of polyhydramnios. This case suggests that acute obstructive uropathy should be considered as a rare cause of acute renal failure even in cases with seemingly normal pregnancy-induced physiological urinary tract dilation.