Laser coagulation of placental anastomoses with a 30° fetoscope in severe mid-trimester twin-twin transfusion syndrome with anterior placenta

Objective: To assess outcome after fetoscopic laser coagulation (FLC) of placental vascular anastomoses with the 30° fetoscope in mid-trimester severe twin-to-twin transfusion syndrome (TTTS) with completely anterior placenta compared with the regular 0° fetoscope in TTTS with other placental locations. Methods: This was a prospective study of 176 consecutive monochorionic twin pregnancies undergoing FLC for severe TTTS. Of these, 51 patients required use of the 30° fetoscope (study group) and 125 placental locations permitted use of the 0° fetoscope (controls). Results: The two groups had very similar outcomes. The median gestational age at FLC in the study group vs. control group was 21.0 (range, 17.4-24.6) weeks vs. 20.6 (range, 15.9-24.6) weeks. Both fetuses survived in 58.8% (30/51) of study patients vs. 66.4% (83/125) of controls. At least one fetus survived in 84.3% (43/51) of study patients and 88.8% (111/125) of controls (P = 0.45). Study patients delivered at a median of 34.1 (range, 25.0-38.4) weeks and controls at 34.0 (range, 25.0-40.3) weeks' gestation. Conclusions: Use of a 30° fetoscope for FLC in cases of technically challenging extensive anterior placentation is associated with an outcome that is very similar to that achieved when a 0° fetoscope is used in cases of more favorable placental location.