OC116: Update on laser treatment in TTTS

Monochorionic twin pregnancies complicated by severe twin-to-twin transfusion syndrome at midgestation can be treated by either serial amnioreduction (removal of large volumes of amniotic fluid) or by selective fetoscopic laser coagulation of the communicating vessels on the chorionic plate. We conducted a randomized trial to compare the efficacy and safety of these two methods of treatment. Pregnant women with severe twin-to-twin transfusion syndrome before 26 weeks of gestation were randomly assigned to laser therapy or amnioreduction. We assessed perinatal survival of at least one twin (a prespecified primary outcome), survival of at least one twin at 6 months of age, and survival without neurologic morbidity at 6 months of age. The study was concluded early, after randomization of 72 women to the laser group and 70 to the amnioreduction group, based on results of a planned interim analysis demonstrating a significant benefit in the laser group. As compared with the amnioreduction group, the laser group had a higher likelihood of survival of at least one twin both in the perinatal period (76.4 percent vs. 55.7 percent; relative risk = 1.37 [95 percent confidence interval: 1.07–1.75]; P = 0.009) and at 6 months of age (P = 0.002). As compared with the amnioreduction group, infants in the laser group had a lower incidence of periventricular leukomalacia (5.6 percent vs. 14.3 percent; P = 0.02), and were more likely to be alive without neurological morbidity at 6 months (52.1 percent vs. 31.4 percent; P = 0.003). Endoscopic laser coagulation of anastomoses is a more effective first-line treatment of severe twin-to-twin transfusion syndrome diagnosed before 26 weeks' of gestation than serial amnioreduction.