Management of Late Twin-to-Twin Transfusion Syndrome beyond 26 Weeks: Comparison between Fetoscopic Laser Therapy versus Traditional Management.

INTRODUCTION: A proportion of monochorionic diamniotic (MCDA) twin pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) can present after 26 weeks of gestation. The aim of this study was to compare perinatal outcomes of late TTTS treated by fetoscopic laser coagulation versus traditional management with amniodrainage and/or emergency preterm cesarean delivery (CD).

METHODS: Retrospective cohort from January 2012 to January 2023 of consecutive MCDA twin pregnancies complicated by TTTS after 26 weeks and evaluated in our referring centers. We analyzed perinatal outcomes of cases treated with fetoscopic laser surgery at our national referral fetal surgery center in Queretaro, Mexico, and compared them with those managed with traditional management (amniodrainage and/or emergency preterm CD). The primary outcome was survival at discharge and the secondary outcome was gestational age (GA) at birth.

RESULTS: Among the study population, 46 TTTS cases were treated by fetoscopy at 27+6 (26+0-31+0) weeks+days and were compared with a group of 39 cases who underwent emergency preterm CD. In comparison to the group who underwent traditional management, the group treated by laser fetoscopy showed a significantly higher GA at birth (32+3 vs. 29+1 weeks+days, p < 0.001), lower frequency of preterm delivery below 37 weeks (91.3% vs. 100%, p = 0.06), 34 weeks (63.0% vs. 100%, p < 0.001), 32 weeks (50% vs. 74.4%, p = 0.02), or 30 weeks (28.3% vs. 53.8%, p = 0.01), and significantly higher perinatal survival (89.1% vs. 71.8%, p < 0.05 of at least one twin; and 65.2% vs. 38.5%, p = 0.01 of both twins, respectively).

CONCLUSION: MCDA twins complicated with TTTS can be treated with fetoscopic laser surgery between 26 and 31 weeks of gestation, which is a feasible and safe option, and such cases are associated with a higher GA at birth and better perinatal survival than those managed with amniodrainage and/or emergency preterm CD.