Troubles with twins: fetoscopic therapy

Monochorionic twin gestations present challenges in perinatal management not seen in dichorionic twins or singleton pregnancies. Monochorionic twin gestations may be complicated by (1) a monoamniotic presentation, (2) a structurally anomalous cotwin, (3) twin reversed arterial perfusion sequence, (4) and the twin-twin transfusion syndrome. Each of these conditions is associated with increased morbidity and mortality rates. Although a variety of therapeutic interventions are available, fetoscopic surgery is a promising new approach to these conditions. Advances in microinstrumentation have allowed for the wider application of fetoscopy for a variety of prenatally diagnosed conditions, including "troubles with twins." This article examines the natural history, pathophysiology, diagnosis, and indications for fetoscopic surgery in complicated monochorionic twin gestations.