Supplementary Material for: Neurodevelopmental Outcome in High-Risk Congenital Diaphragmatic Hernia Patients: An Appeal for International Standardization

<br><strong><em>Background:</em></strong> Since mortality in congenital diaphragmatic hernia (CDH) is decreasing, morbidity such as neurodevelopmental outcome is becoming increasingly important. <b><i>Objectives:</i></b> We evaluated neurodevelopmental outcome in high-risk CDH patients treated according to the CDH EURO Consortium standardized treatment protocol. <b><i>Methods:</i></b> This observational, prospective cohort study was conducted in two European centers. Neurodevelopment of 88 patients (Rotterdam n = 49; Rome n = 39) was assessed at 12 and 24 months with the Bayley Scales of Infant Development (BSID)-II-NL (Rotterdam) or BSID-III (Rome). Data of the centers were analyzed separately. <b><i>Results:</i></b> Cognition was normal in 77.8% of children from Rotterdam and in 94.8% from Rome at 12 months, and in 70.7 and 97.4%, respectively, at 24 months. Motor function was normal in 64.3% from Rotterdam and in 81.6% from Rome at 12 months and in 45.7 and 89.8%, respectively, at 24 months. Longer length of hospital stay (LoS) was associated with worse cognitive outcome and motor function; LoS, low socioeconomic status, and ethnicity were associated with lower cognition. <b><i>Conclusions:</i></b> At 2 years, most CDH patients have normal cognition, but are at risk for motor function delay. Due to differences in outcomes between centers, careful interpretation is needed before conclusions can be drawn for other centers. Future multicenter collaboration should not only focus on standardization of postnatal care, but also on international standardization of follow-up to identify risk factors and thereby reduce morbidity.