Monoamniotic twin discordant for bilateral renal agenesis with normal pulmonary function

A 22-year-old G4P3 woman with a twin pregnancy underwent an uncomplicated delivery at 35 weeks of gestation of normal-appearing twin boys. One of the boys returned 24 hours later with no voiding since birth. He was doing well with no respiratory difficulties and normal physical examination findings. Renal/bladder ultrasonography and computed tomography of the abdomen and pelvis revealed no evidence of kidneys. The admission laboratory values were consistent with renal failure. A peritoneal dialysis catheter was inserted and peritoneal dialysis started. Our patient died at 2 months old secondary to complications from the peritoneal dialysis. We describe the unusual case of a monoamniotic twin discordant for bilateral renal agenesis with normal pulmonary function. This case shows the importance of normal renal function in the production of amniotic fluid and its relationship to the proper development of the pulmonary system.