Increasing prevalence of congenital hypothyroidism emerges as a growing concern in Jordan

Congenital hypothyroidism (CH) is a prevalent childhood endocrine disorder associated with irreversible neurological consequences. Its global incidence is on the rise.

To estimate CH incidence in Jordan and assess the potential utility of incorporating (fT4) measurements into the screening process.

This retrospective analysis examined thyroid function test results for infants born at our center between 2016 and 2020. Infants born before 28 weeks and those screened after 14 days of life were excluded. Screening occurred between days 3 and 7 of life, and thyroid-stimulating hormone (TSH) and T4 levels were measured concurrently from peripheral venipuncture blood samples. A TSH cutoff of < 5 mIU/L was considered normal. Values between 5 and 20 mIU/L were equivocal, requiring repeat tests. TSH levels exceeding 20 mIU/L were considered critical.

A total of 10521 infants were included in the study, and 26 were diagnosed with CH, yielding an incidence of 1 in 400 live births. Females constituted 57.7% of CH cases. All CH cases had initial TSH values exceeding 5.0 mIU/L, with clustering above 20 mIU/L. Six CH infants had Down syndrome, accounting for 23.1% of CH cases.

Our study revealed a high incidence of CH in Jordan, marking a significant increase from previously reported rates. We recommend a national study to investigate risk factors and underlying causes of CH in our population. Furthermore, we advocate for the use of TSH alone with a cutoff value of < 5 mIU/L for screening purposes.