Prasad, S.Sileo, F. G.Binder, J.Brunelli, E.Chianchiano, N.Coutinho, C. M.D'Antonio, F.Döbert, M.Fichera, A.Gielchinsky, Y.Hecher, K.Iacovella, C.Malone, S.Martinez-Varea, A.Nørgaard, L. N.Rodo, C.Simões, T.Slaghekke, F.Yinon, Y.Khalil, A.Bahlmann, F.Carreras, E.Alletti, S. G.Yaghi, O.Lopriore, E.Okido, M. M.Markovich, A.Mohammed, D.Moreno-Perez, E.Prefumo, F.Queirós, A.Rosello, J. M.Sundberg, K.Yeoh, M.Youssef, A.Ulusoy, C. O.2026-03-112026-03-112026-020960-7692PURE: 154943889PURE UUID: 9c0ec02e-ac1a-4ee6-8be6-67b60e5d3607Scopus: 105030227685http://hdl.handle.net/10362/201251Publisher Copyright: © 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.Objective: Data on early-onset twin-to-twin transfusion syndrome (TTTS) are scarce and, therefore, evidence-based counseling and management of these pregnancies are challenging. This study aimed to investigate survival rates and establish predictors of survival after fetoscopic laser surgery (FLS) for early-onset TTTS. Methods: This was an international multicenter retrospective cohort study of monochorionic diamniotic twin pregnancies complicated by TTTS diagnosed before 18 + 0 weeks' gestation that underwent FLS. The primary outcome was dual-twin survival at 28 days after birth. Secondary outcomes included survival of at least one twin and dual-twin demise at 28 days after birth. Monoamniotic twin, triplet and higher-order multiple pregnancies, pregnancies with chromosomal or structural fetal anomaly and TTTS cases not treated by FLS were excluded. Pre-, intra- and postoperative characteristics were analyzed using multivariable logistic regression analysis. Discriminative performance was assessed using receiver-operating-characteristics-curve analysis. Results: A total of 485 cases of early-onset TTTS that underwent FLS were included. The rates of dual-twin survival and survival of at least one twin at 28 days after birth were 51.5% (250/485) and 76.7% (372/485), respectively, while 23.3% (113/485) of cases resulted in dual-twin demise. Multivariable logistic regression analysis showed that absent or reversed end-diastolic flow (AREDF) in the donor umbilical artery (adjusted odds ratio (aOR), 0.487 (95% CI, 0.273–0.867)) and absent or reversed a-wave in the donor ductus venosus (aOR, 0.299 (95% CI, 0.110–0.810)) at the time of TTTS diagnosis were associated independently with decreased odds of dual survival, while higher gestational age at birth was associated with increased odds of both dual-twin survival (aOR, 1.172 (95% CI, 1.117–1.229)) and survival of at least one twin (aOR, 2.053 (95% CI, 1.699–2.481)). The model for dual-twin survival showed modest discriminative performance with poor overall fit. Conclusions: The presence of AREDF in the donor umbilical artery and absent or reversed a-wave in the donor ductus venosus, at the time of diagnosis of TTTS, and lower gestational age at birth were independent adverse predictors for dual-twin survival following FLS in cases of TTTS diagnosed before 18 weeks. Future studies should explore the impact of surgical technique on survival rates.394094engearlyintrauterine demiselaserMCDAmonochorionic diamnioticsurvivalTTTStwintwin-to-twin transfusion syndromeRadiological and Ultrasound TechnologyReproductive MedicineRadiology Nuclear Medicine and imagingObstetrics and Gynaecologyjournal article10.1002/uog.70178https://www.scopus.com/pages/publications/105030227685