Discordant Renal Agenesis in Monochorionic Diamniotic twins with Spontaneous Septostomy of the Dividing Membrane
ePoster
Authors: Ryan Lauzardo, University of Florida College of Medicine Frederick Ashby, University of Florida Abtahi Tishad, University of Florida College of Medicine Emily Allard-Phillips, University of Florida/Obstetrics and Gynecology Erica Smith, University of Florida Robert Egerman, University of Florida Mehmet Genc, University of Florida College of Medicine
Monozygotic twins are infrequent, accounting for 1:250 of spontaneous conceptions. Seventy percent of monozygotic pregnancies are Monochorionic Diamniotic (MCDA) and this determination is preferentially made during the first trimester ultrasound examination. Rarely MCDA gestations become a pseudo- monoamniotic pregnancy where upon spontaneous rupture of the amnion of one twin results in the MCDA pregnancy becoming Monochorionic Monoamniotic (MCMA). This unusual occurrence of membrane perforation is estimated at 1.8%. The importance of recognizing this finding involves the differences in fetal surveillance, timing of delivery and mode of delivery in MCDA versus MCMA pregnancies. Our case involves what was originally a MCDA pregnancy which spontaneously became MCMA. Confounding this was one twin having bilateral renal agenesis. The spontaneous septostomy was serendipitously lifesaving, providing the fetus exposure to normal volumes of amniotic fluid allowing for normal pulmonary development. We discuss the diagnostic and management challenges in this pregnancy and offer an approach for surveillance and management.