Unique Complications of Monochorionic Twins: Diagnosis and Management

Monochorionic (MC) twins run the highest risk of complications and the wellbeing of one fetus crucially depends on that of the other because of vascular anastomoses in the common placenta. The management for unique complications of MC twins is also influenced by the vascular anastomoses on the chorionic plate. Those unique complications include twin-twin transfusion syndrome, twin reversed arterial perfusion, MC twin with selective intrauterine growth restriction, and MC twin with one anomaly. Diagnosis of the unique complications of MC twin pregnancy is heavily dependent on ultrasonography, and management would largely be dependent on the sonographic guide procedures. Such complications of MC twins are relatively rare but the management is somewhat complex; the obstetrician should be familiar with the diagnosis and the rationale of management.