Perinatal outcomes of twin pregnancies complicated by early twin‐to‐twin transfusion syndrome treated with fetoscopic laser surgery

Objective: The aim of this study was to evaluate the perinatal outcomes of monochorionic diamniotic (MCDA) twin pregnancies complicated by early twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic laser surgery (FLS), and to compare rates of fetal survival across Quintero stages. Methods: This was a multicenter retrospective cohort study of MCDA pregnancies complicated by TTTS diagnosed ≤ 18 weeks' gestation (early TTTS) that underwent FLS from January 2007 to August 2023. Monoamniotic twins, triplets or higher-order multiple gestations, and pregnancies complicated by genetic or structural anomalies were excluded. Demographic data, gestational age at diagnosis and at FLS, Quintero stage at diagnosis and details of management of the pregnancy, including complications and perinatal outcomes, were obtained from patient records at each participating center. The primary outcome was survival at 28 days after birth. Results: In total, 678 MCDA pregnancies with early TTTS were identified, of which 550 underwent FLS. Of these, 485 cases had a known pregnancy outcome and were therefore included. The median gestational age at diagnosis was 17 + 0 (interquartile range (IQR), 16 + 3 to 17 + 4) weeks, and median gestational age at FLS was 17 + 4 (IQR, 17 + 0 to 17 + 6) weeks. The most common Quintero stage at diagnosis was Stage III (46.0% (223/485)). At least one postoperative complication occurred in 36.5% (177/485) of cases, including preterm prelabor rupture of membranes, intrauterine fetal demise of the cotwin, vaginal bleeding, septostomy and pregnancy loss. Dual-twin survival was reported in 51.5% (250/485) of cases, while survival of at least one twin was reported in 76.7% (372/485). There were no surviving fetuses in 23.3% (113/485) of pregnancies. When considering cases diagnosed ≤ 16 weeks, the rate of survival of at least one twin was 87.5% for cases diagnosed at Quintero Stages I-II vs 59.5% for Stages III-IV (P = 0.019). Conclusions: The diagnosis and management of TTTS ≤ 18 weeks are more complex than those of TTTS diagnosed > 18 weeks. More early-TTTS cases were diagnosed at Quintero Stage III, but the overall survival rate was not significantly different between cases diagnosed at Quintero Stages I-II vs Stages III-IV, except when the diagnosis was made ≤ 16 weeks, in which case the survival rate was higher among cases diagnosed at Stages I-II. Revisions to the diagnostic criteria for early TTTS should be considered. © 2026 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.