Figure 3.

Features of the monochorionic placenta include separate placental cord insertions with presence vascular anastomoses (circles and placental dye injection image) that link the fetal circulation. The natural line along the placenta where the vessels from each twin meet is the vascular equator (dotted line). Volume and substance shift from the donor to the recipient twin is responsible for development of twin to twin transfusion syndrome. Fetoscopic laser surgery is performed by coagulating the individual anastomoses and the intervening chorionic plate to dichorionize the placenta (dotted line).