M. Noori-Shadkam
M.H. Mosadegh
M. Mirzaei
MR. Movahedi Nia
M. Jafarizadeh

Introduction: Congenital hypothyroidism (CH) is one of the most common preventable causes of mental retardation. Its worldwide incidence is estimated to be one in ۲۵۰۰-۵۵۰۰ births. Assessment of thyroid gland in neonates is critical. The aims of this study were to demonstrate the incidence of CH in neonates born in Yazd province, Iran in ۱۳۸۹ (۲۰۱۰) and compare the results with other reported studies and investigate biochemical characteristics of affected infants. Materials & Methods: This is an analytical descriptive cross-sectional study. The study was conducted on all infants (۱۳۰۲۲ births) born in ۱۳۸۹ (March ۲۰۱۰-March ۲۰۱۱). Thyroid stimulating hormone (TSH) was measured using ELISA technique. Results: Forty five infants suffered from congenital hypothyroidism with an overall incidence of one in ۲۸۹ live births. Twenty five of the diagnosed infants were males (incidence ۱:۲۶۱) and twenty were females (incidence ۱:۳۲۵). The incidence of CH in boys was more than girls (P-value = ۰.۲۹۵). The highest incidence of CH was observed in spring followed by summer and the lowest incidence was in autumn followed by winter (P-value=۰.۰۰۰. Conclusion: The CH incidence was ۱۰.۳ to ۱۳.۸ times more than other countries. The highest CH incidence was in spring followed by summer and the lowest incidence was in autumn followed by winter. It is important that a larger size of cases need to be screened and more information on the aetiology of the affected infants to be obtained

Hypothyroidism, Incidence, Intellectual Disability, Thyroid Gland, Infants, Hypothyroidism, Incidence, Intellectual Disability, Thyroid Gland, Infants