Laser coagulation of placental anastomoses with a 30 degrees 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 degrees fetoscope in mid-trimester severe twin-to-twin transfusion syndrome (TTTS) with completely anterior placenta compared with the regular 0 degrees 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 degrees fetoscope (study group) and 125 placental locations permitted use of the 0 degrees 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 degrees 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 degrees fetoscope is used in cases of more favorable placental location.