The incidence of congenital hypothyroidism in neonates born in Chaharmahal and Bakhtiari province from 2015 to 2021; A cross-sectional study

Introduction: Congenital hypothyroidism (CH) is one of the most common endocrine and metabolic disorders and a common preventable cause of mental retardation across the world. This disorder can be prevented if diagnosed and treated before the age of four weeks. Objectives: This study was performed to investigate the incidence rate of CH in infants in Chaharmahal and Bakhtiari province. Patients and Methods: The data of this study were obtained by the CH screening program from 2015 to 2021 in the health deputy of Chaharmahal and Bakhtiari province. Results: A total of 651 patients were diagnosed with CH, which showed an incidence rate of 5.06 per 1000 births (1 per 198 live births) in the province. The highest incidence of the disease was obtained in 2016 and the lowest incidence in 2021. Lordegan city had the highest incidence rate (8.1 per 1000 live births) and Kiar had the lowest one (1.67 per 1000 live births) during the study period. Moreover, the highest and lowest incidence rates in terms of season were observed in winter and summer, respectively. Conclusion: It can be concluded that Chaharmahal and Bakhtiari province, especially Lordegan, is one of the regions with high prevalence of CH in Iran, therefore the incidence rate is not only higher than the national average but also higher than the global average. Hence, the potential causes of this observation deserve further investigation.