Monozygotic Twinning

This article discusses pathologies found in monozygotic twinning. Detailed information is provided regarding the development during monozygotic twin formation: embryo development, twin-to-twin transfusion syndrome, acardiac twinning, vanishing twins, conjoined twins, and Beckwith-Weidmann syndrome twins. An algorithm describing the approach for identifying pathology in a placenta with multiple pregnancies is presented.