Management of twin-to-twin transfusion syndrome: update and current challenges.

Since a 2004 randomized trial established fetoscopy as the gold standard for the treatment for twin-to-twin transfusion syndrome (TTTS), advancements in surgical technique and expert training have considerably improved survival rates to 89% for at least one fetus and 65% for both fetuses. However, many challenges remain. This review provides an update on the current principles, issues, and debates. The Solomon technique has helped improve neonatal outcomes by reducing the risks of postoperative twin anemia-polycythemia sequence and TTTS recurrence. Nevertheless, fetoscopic laser photocoagulation is associated with significant obstetrical risks, including preterm premature rupture of membranes, preterm delivery, and even placental abruption. Additionally, fetal growth restriction, observed in 30% to 50% of cases, may adversely affect double survival rates following fetoscopy, particularly when abnormal Doppler indices are present. Gestational age (GA) at the time of fetoscopy is a critical prognostic factor, as earlier GA is associated with lower survival rates. This consideration raises questions about the optimal timing of the procedure after TTTS diagnosis. Emerging evidence supports expectant management with close ultrasound monitoring for asymptomatic patients with stage I TTTS. In stage III and IV TTTS, laser photocoagulation should not be delayed, whereas stage II TTTS diagnosed at very early GAs might benefit from expectant management until 16 to 17 weeks of gestation. Further advancements, such as flexible video fetoscopy and computer-assisted fetal laser surgery, represent the next frontier in addressing these challenges.