The twin-to-twin transfusion syndrome is a lethal hemodynamic imbalance between identical fetal twins as a result of vascular anastomoses in the monochorionic plate. With a fetoscopic laser photocoagulation the communicating vessels are interrupted, eliminating the inter-twin blood exchange. Since the first instruments were straight and rigid, an anterior located placenta resulted in an impaired visualization of the chorionic plate and coagulation of the vascular equator. Over the years multiple instruments have been developed to reduce these complications. However, these problems still occur within the clinic and are quoted throughout literature. In order to obtain a better understanding of the impaired visualization and decreased coagulation effectiveness, these problems in relation to the clinically aplied instruments, placenta location and the insertion path are simulated within realistic anatomical models.