Fetal Brain Abnormalities Following Laser Surgery for Twin‐to‐Twin Transfusion Syndrome: Imaging Patterns and Evolution
Yada Kunpalin, Elka Miller, Ingrid Larsen, Kamini Raghuram, Catherine Windrim, Nimrah Abbasi, Greg Ryan, Tim Van Mieghem, Shiri ShinarABSTRACT
Introduction
Severe brain injury has been reported following fetoscopic laser ablation (FLA) for twin‐to‐twin transfusion syndrome (TTTS), but imaging patterns and temporal evolution remain poorly defined. This study aimed to characterize the progression of severe brain injury after FLA.
Methods
We conducted a retrospective case series of TTTS pregnancies with severe brain injury identified after FLA at the Ontario Fetal Center (June 2023–March 2025). FLA was performed for Quintero stage ≥ II and selected stage I cases. Severe abnormalities were defined as severe intraventricular haemorrhage or destructive lesions. Serial ultrasound and fetal MRI were reviewed and categorized as early (< 4 weeks) or late (≥ 4 weeks) post‐FLA.
Results
Fifteen fetuses from 14 pregnancies were identified. Mean gestational age at FLA was 19.7 ± 3.2 weeks; 66.7% were stage III–IV and 60% were donor twins. Early imaging ( n = 8) most commonly showed periventricular haemorrhagic infarction (62.5%) and cerebellar haemorrhage (25.0%). Late imaging ( n = 13) predominantly demonstrated cerebral volume loss (76.9%), often involving the parietal lobes, with polymicrogyria (38.5%) and Wallerian degeneration (30.8%). Findings remained unchanged after 4 weeks.
Conclusion
Brain injury after FLA evolves from acute haemorrhagic/ischaemic insults to irreversible destructive changes. These preliminary findings suggest a consistent pattern of injury that warrants further prospective study.