ANTEPARTUM RUPTURE OF DIAMNIOTIC MEMBRANES SEPARATING MONOZYGOTIC TWINS - A CASE-REPORT

The partitioning membrane of a monochorionic, diamniotic twin gestatio n was visualized by ultrasound at weeks 18 and 22. The pregnancy progr essed without difficulty to week 37. Delivery by cesarean section was warranted when intrapartum fetal heart rate decelerations were detecte d in one of the twins. Cord entanglement was noted at the time of deli very. Ultrasonography at week 29 had failed to demonstrate a partition ing membrane but as late as week 36 did not visualize cord entanglemen t. The diamniotic environment became monoamniotic from an unknown even t some time in the fate second or third trimester of pregnancy. This r eport emphasizes that ultrasonographic visualization of a partitioning membrane does not preclude future cord accidents.