Prevalence of Congenital Hypothyroidism in Iranian Infants

Congenital hypothyroidism is one of the most common endocrine diseases and one of the main causes of mental disability and delayed sensory and motor development in infants. The aim of this review article is to determine the general prevalence of congenital hypothyroidism in Iranian infants.

In this systematic review and meta-analysis, a comprehensive review of the Scientific Information Database (SID), Medline (PubMed), ScienceDirect and Google Scholar was conducted using the keywords “congenital hypothyroidism”, “infants” and “screening” until November 2022. The extracted data were entered into the Comprehensive meta-analysis software (Version 2) and the meta-analysis was analyzed using the random-effects model in the studies.

248 articles were initially found in the search of the investigated databases. After removing 169 duplicate articles and removing them based on the inclusion and exclusion conditions of the studies, 79 articles were included in the secondary evaluation and finally, after omitting 60 irrelevant articles, 17 articles were included in the meta-analysis review. In a review of 17 studies with a sample size of 674,466 Iranian infants, based on a meta-analysis, the prevalence of congenital hypothyroidism in Iranian infants was 0.002 (95% CI= 0.002-0.003), and in terms of percentage was reported 0.2% and 2 per 1000 live births.

The results of the present study show that the prevalence of congenital hypothyroidism in Iranian infants is 2 per 1000 live births, which indicates the high prevalence of this disease in infants in the country, and it is necessary to inform pregnant mothers and to continue screening at birth.