Twin-to-twin transfusion syndrome: from pathophysiology to long-term outcome-a narrative review

Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies caused by unbalanced placental vascular anastomoses. Fetoscopic laser photocoagulation (FLP) is the standard treatment, although neonatal outcomes remain variable. This review aimed to summarize immediate, short-term, and long-term neonatal outcomes following FLP for TTTS. A narrative review of published clinical trials, cohort studies, and meta-analyses was conducted, focusing on survival, neurological, cardiovascular, and renal outcomes in neonates following FLP, including comparisons between selective and Solomon techniques. FLP significantly improves survival rates, with at least one twin surviving in 80-90% of cases. However, prematurity remains frequent, with median delivery at 32-34 weeks. Short-term brain injury occurs in 2-8% of cases, and long-term neurodevelopmental impairment affects 3-14% of survivors. Cardiovascular complications, such as pulmonary stenosis and aortic coarctation, develop at follow-up in 8% of cases, while renal dysfunction, primarily in donors, is reduced after FLP compared with expectant management.

FLP substantially enhances survival in TTTS, but neonatal morbidity remains a subject of concern. Persistent neurological, cardiac, and renal complications warrant multidisciplinary, long-term follow-up to optimize developmental outcomes for survivors.

• Fetoscopic laser photocoagulation improves survival in severe twin-to-twin transfusion syndrome compared with amnioreduction.

• Despite improved survival, long-term neurological, cardiac, and renal morbidities remain significant, emphasizing the need for multidisciplinary, prolonged postnatal follow-up of TTTS survivors.