Clinical and multi-omics characterisation of early neurodevelopmental disorders associated with critical congenital heart disease: the prospective cohort CATAMARAN neonatal study protocol.

introductionCritical congenital heart disease (CHD) is associated with neurodevelopmental disorders, recognised as the most common long-term morbidity in affected children. In critical CHD, that is, CHD requiring cardiac surgery within the first 3 months of life, 30%-50% of children have lower developmental scores. Therefore, early identification of at-risk infants is crucial, yet there is no scientifically evaluated care programme in France. This study aims to evaluate early neurodevelopmental status in infants with prenatally diagnosed critical CHD and to determine how intrinsic susceptibility, prenatal and postnatal factors are functionally associated with developmental delay in this population. METHODS AND ANALYSIS: Caractérisation et Accompagnement des Troubles du neurodéveloppement Associés aux MAlfoRmations cArdiaques coNgénitales (CATAMARAN) is a prospective, multicentre cohort study including 150 fetuses with critical CHD and their parents across eight French tertiary CHD centres. The primary objective will be to estimate the proportion of developmental delay at 6 months using the Bayley Scales of Infant and Toddler Development. Secondary objectives will include exploring potential prenatal, perinatal, perioperative determinants of developmental delay. Data collection will span pregnancy to 6 months of age including clinical assessments, maternal questionnaires (stress and nutrition), multimodal imaging and extensive biobanking (placenta, cord and peripheral blood, stool samples). To explore potential genetic and other multi-omic factors involved in the occurrence of a developmental delay, a case-control analysis will be conducted within the cohort. ETHICS AND DISSEMINATION: Clinical and biological data will be collected through a secure system, with anonymised samples analysed in specialised facilities under collaborative agreements. Data confidentiality, traceability and long-term storage are ensured through controlled access and audit trails. Study results will be published and shared with families and the public through the patient association Petit Coeur de Beurre. This study received approval from a French ethics committee in November 2024 (no. 2024-A00425-42). TRIAL REGISTRATION NUMBER: NCT06690151.