Twin Reversal Arterial Perfusion Syndrome

In this research study, the investigators want to learn more about the role of new innovative surgical devices, the Karl Storz Curved and Straight Fetoscopes for in-utero surgery. A fetoscope is like a small telescope that can see inside of the uterus (womb) during minimally invasive surgery. The curved scope is used for patients with an anterior placenta (front of uterus), while the straight scope is used for patients with a posterior placenta (back of uterus). The scopes will be used to assist in procedures involving fetoscopic laser photocoagulation (FLP), which is a minimally invasive surgery that uses a small camera (fetoscope) to locate abnormal blood vessel connections in the placenta and seal them off using laser energy. These fetoscopes will be utilized in the diagnosis and management of various fetal conditions that can arise during pregnancy. Outcome data will be reported in a descriptive statistical analysis. The investigators will assess the surgical outcomes, short and long-term morbidity, complications, and gestational age of participants in order to evaluate the benefit of using these devices.

Multi-center open-label randomized controlled trial to assess if early intervention (12.0-14.0 weeks) (study group) improves the outcome of TRAP sequence as compared to late intervention (16.0-19.0 weeks) (control group). The investigators will randomly assign women diagnosed with TRAP sequence diagnosed between 12.0 and 13.6 weeks to an early or late intervention group (1:1), using a web-based application and a computer-generated list with random permuted blocks of sizes 2 or 4 (www.sealedenvelope.com), stratified by gestational age (GA) at inclusion (11.6 -12.6 weeks versus 13.0-13.6 weeks). Analysis will be by intention to treat.