title: A rare case of antepartum spontaneous septostomy in a monochorionic diamniotic twin pregnancy.
abstract: Spontaneous septostomy in a monochorionic diamniotic twin pregnancy is a rare phenomenon. We present a case of monochorionic diamniotic twin pregnancy with an intact dividing membrane seen in the 1st half of the pregnancy. At 26 weeks, when she was assessed for preterm contractions, the dividing membrane was not documented, which suggested spontaneous septostomy. There had been no invasive procedures during the pregnancy. She subsequently delivered at 29 weeks, secondary to preterm labor. No dividing membrane was noticed at the time of caesarian section. Spontaneous septostomy can complicate the management of monochorionic diamniotic twins by creating a pseudomonoamniotic environment resulting in cord entanglement, and difficulty in the diagnosis and management of twin-twin transfusion syndrome. We believe that such a case should be managed as monochorionic monoamniotic twin gestation.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Foothills Medical Center, Calgary, AB, Canada T2N 2T9.
authors.forename: Rati
authors.initials: R
authors.lastname: Chadha
authors.forename: Ian R
authors.initials: IR
authors.lastname: Lange
authors.forename: Lisa
authors.initials: L
authors.lastname: Bratz
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Cooper
authors.forename: Anne
authors.initials: A
authors.lastname: Roggensack
authors.forename: Jo-Ann
authors.initials: JA
authors.lastname: Johnson