Fetal Brain Abnormalities Following Laser Surgery for Twin-to-Twin Transfusion Syndrome: Imaging Patterns and
Yada Kunpalin1,2,3, Elka Miller2,3,4, Ingrid Larsen1,2
1Fetal Medicine Unit, Department of Obstetrics & Gynaecology, Mount Sinai Hospital Toronto, Toronto, Ontario, Canada.
Prenatal Diagnosis
|June 23, 2026
Summary
Brain injury after fetoscopic laser ablation (FLA) for twin-to-twin transfusion syndrome (TTTS) progresses from acute damage to permanent changes. Imaging reveals consistent patterns of fetal brain injury following FLA treatment.
Area of Science:
- Fetal Medicine
- Neonatal Neurology
- Medical Imaging
Background:
- Fetoscopic laser ablation (FLA) for twin-to-twin transfusion syndrome (TTTS) can lead to severe brain injury.
- The imaging patterns and temporal evolution of this injury are not well-defined.
Purpose of the Study:
- To characterize the progression of severe brain injury following FLA in TTTS pregnancies.
- To identify consistent imaging patterns and their evolution over time.
Main Methods:
- Retrospective case series of TTTS pregnancies with severe brain injury post-FLA.
- Review of serial ultrasound and fetal MRI scans (early <4 weeks, late ≥4 weeks post-FLA).
- Inclusion criteria: Quintero stage ≥II or selected stage I TTTS, severe intraventricular haemorrhage, or destructive lesions.
Main Results:
- Fifteen fetuses from 14 pregnancies were analyzed; mean gestational age at FLA was 19.7 weeks.
- Early imaging showed periventricular haemorrhagic infarction (62.5%) and cerebellar haemorrhage (25.0%).
- Late imaging demonstrated cerebral volume loss (76.9%), polymicrogyria (38.5%), and Wallerian degeneration (30.8%), with findings stable after 4 weeks.
Conclusions:
- Brain injury after FLA evolves from acute insults to irreversible destructive changes.
- A consistent pattern of fetal brain injury following FLA is suggested.
- Further prospective studies are warranted to confirm these preliminary findings.
