First described by Quintero and collaborators in 1994, umbilical cord occlusion may be required for the treatment of complicated monochorionic twins. Our physicians perform this procedure in the least invasive and safest way to maximize the likelihood of a good pregnancy outcome. Umbilical cord occlusion is only offered as a last resort when no other plausible alternative is available. The procedures are done in the Hospital in the main Operating Room, under maximum antiseptic technique.