Improvement in Twin Survival After Fetoscopic Laser Photocoagulation in Monochorionic Diamniotic Pregnancies with Twin-to-Twin Transfusion Syndrome: A Retrospective Cohort Study.

Twin-to-twin transfusion syndrome (TTTS) affects 10-15% of monochorionic diamniotic (MCDA) twin pregnancies and is associated with high perinatal mortality if left untreated. Selective Fetoscopic Laser Photocoagulation (SFLP) is the current standard of care for advanced-stage TTTS. This retrospective cohort study aimed to assess survival outcomes following SFLP and evaluate the learning curve associated with its implementation. It included 300 MCDA twin pregnancies with TTTS treated by SFLP from October 2018 to December 2024. Patients were chronologically divided into three equal groups (n = 100 per group) based on the order of procedure to assess outcome trends over time. Primary outcome was dual survival at birth; secondary outcomes included survival of at least one fetus, gestational age at delivery, birth weight, and neonatal complications. Multivariable logistic regression was used to assess clinical and procedural factors associated with dual survival, while CUSUM analysis was employed to evaluate the learning curve. Among 300 cases, dual survival was achieved in 57% of pregnancies. In multivariable logistic regression, clinical factors, including Quintero stage, placental orientation, and gestational age, were not significantly associated with outcomes (p > .05). The treatment cohort remained the sole independent predictor of survival, with significantly lower odds of success in Group 1 (OR 0.041; 95% CI [0.004, 0.429]) and Group 2 (OR 0.051; 95% CI [0.005, 0.492]) compared to Group 3 (p < .01). CUSUM analysis demonstrated that procedural competence, defined by sustained adequate survival rates, was achieved after the 141st procedure. This study demonstrates improved survival outcomes in TTTS cases treated with SFLP over time, confirming a significant institutional learning curve. The findings highlight the importance of surgical experience and procedural standardization. In resource-limited settings, establishing structured training and mentorship is essential to optimize outcomes and safely expand access to fetal therapy.