Prenatal and postnatal findings in monochorionic, monoamniotic twins discordant for bilateral renal agenesis-dysgenesis (perinatal lethal renal disease).

We report on a male twin born with no functional renal tissue and without the extrarenal manifestations of Potter facies, skin changes, club feet and pulmonary hypoplasia. The monoamniotic co-twin had normal renal function, thereby maintaining sufficient amniotic fluid to avoid the classic presentation of Potter's syndrome. Prenatal diagnosis of this condition allowed prompt confirmation of these findings and support for the parents without unnecessary intervention. This experiment of nature demonstrates the necessity of normal renal function in the maintenance of amniotic fluid and its relationship to the proper development of the pulmonary and integumentary systems.