Because the adverse effects to the AGA twin of the spontaneous demise of the SIUGR twin are mediated through placental vascular anastomoses, we have proposed obliterating such anastomoses via endoscopic fetal surgery. We have developed a technique that allows us to identify the vascular anastomoses present in monochorionic placentas. Briefly, deep AV communications are identified on the surface of the placenta by noting that the terminal end of the artery of one of the fetuses does not have a corresponding returning vein to the same fetus. We have speculated that the separation of the circulations may be of benefit in monochorionic twins affected by SIUGR by preventing the adverse effects that may result from the spontaneous demise of the IUGR twin. Our goal is to evaluate with a randomized clinical trial the outcome of SIUGR managed either expectantly or with SLPCV.