Acta Paediatr. 2024 Nov 1. doi: 10.1111/apa.17479. Online ahead of print. ABSTRACT AIM: This study aimed to assess the cognitive development of individuals with congenital hypothyroidism. METHODS: Using hospital records, we identified 180 patients with congenital hypothyroidism born between 1980 and 2018 in Turku and Kuopio University Hospital catchment areas.