Neurodevelopmental Outcome After Fetoscopic Laser Surgery for Twin-twin Transfusion Syndrome: A Systematic Review of Follow-up Studies from the Last Decade

Objective: To review the literature on long-term neurodevelopmental outcome after fetoscopic laser surgery for twin-twin transfusion syndrome (TTTS).Methods: A literature search in PubMed, Embase, Emcare, Web of Science, Cochrane library, and Academic Search Premier was performed. Inclusion criteria were studies between 2009 and 2019 in TTTS-survivors treated with fetoscopic laser surgery and followed-up after the neonatal period with cognitive developmental tests and neurologic exams. Exclusion criteria were non-English articles and reviews, case reports, letters, and guidelines.Results: Nineteen articles were included. Long-term severe neurodevelopmental impairment (NDI) was reported by seven and ranged from 4.0% to 18.0% with a mean of 9.7% (95% confidence interval (CI): 7.8-11.5). The prevalence of cerebral palsy ranged from 1.6% to 18.2%, with a mean of 5.1% (95%CI: 4.1-6.2). The mean prevalence of minor impairment was 13.7% (95%CI: 11.4-16.0). However, only 78.9% (15/19) studies used a validated neurodevelopmental test. As studies lack uniform definitions of primary outcome, timing of follow-up, inclusion criteria, and methods, adequate comparison is hampered.Conclusion: The prevalence of severe NDI and cerebral palsy after fetoscopic laser surgery for TTTS in the last decade remains stable around 9.7% and 5.1%, respectively. International agreements on primary outcomes, methods, and follow-up are necessary to improve the knowledge of NDI in TTTS-survivors.