Prevalence and predictive factors of transient and permanent congenital hypothyroidism in Fars province, Iran

Abstract

Introduction There is no data on the number as well as the prevalence of congenital hypothyroidism (CH) in the Fars province. Hence, we designed this study to analyze the latest data and the possible predictive factors on transient and permanent CH in this province. Method This cross sectional study is based on the Fars province screening data from 2013 to 2016. A total of 294,214 newborns were screened with 938 confirmed cases of CH, which were included in this study. After recall and completion of the missing data, follow-up data for 642 CH cases with thyroid stimulating hormone (TSH) concentrations and levothyroxine doses for ten outpatient visits and final transient vs. permanent CH diagnosis were included. Results The incidence rate was 1:313.66, and out of the 642 CH cases, 66.04 % had permanent CH, while 33.96 % had transient CH. TSH level trend during the outpatient visits were not statistically different between the two groups (P = 0.312). A cutoff point of > 2.25 levothyroxine µg/kg (sensitivity: 76.11 %, specificity: 58.52 %) at the third year and a TSH concentration of > 43.35 mIU/L at the venous sampling (initial TSH) (sensitivity: 31.66 %, specificity: 90.32 %) were the predictive factors for permanent CH. Conclusion Fars province has one of the highest incidence rate of CH in Iran. Levothyroxine dose at the 3rd year and the 1st venous TSH sample are the predictive factors for permanent CH in the Iranian population; however, TSH concentrations during follow ups are unreliable predictors.

The Relationship Between Maternal Hypothyroidism and the Incidence of Congenital Hypothyroidism in Infants: A Cross-Sectional Study

“…This was similar to the results of a study in Yazd, Iran, noting that neonatal hypothyroidism was observed at a rate of 3.4% per 1000 live births (1 in 309 male infants and 1 in 286 female infants) (24). In another study in Fars province, this rate was reported to be 1:313.66 from 2013 to 2016 (30). The overall incidence of CH was reported as 1:2695 in Zurich (31) and 1:2000-1:4000 worldwide (4,31).…”

Diagnostic Re-Evaluation and Potential Predictor Factors of Transient and Permanent Congenital Hypothyroidism in Eutopic Thyroid Gland

“…Multivariate analysis for this cutoff also showed a higher risk for PCH and was also associated with a higher risk of extra-thyroid malformation rate. Oron et al [ 11 ] and Kang [ 8 ] reported a similar cutoff for serum TSH levels at diagnosis, while other studies reported a lower cutoff for TSH, between 28.4 and 43.35 mcUI/mL [ 8 , 11 , 31 , 32 ]. In our cohort, specificity of 100% was achieved for TSH levels below 21.9 mcUI/mL.…”

Comparing the Characteristics of Neonates with FalsePositive Congenital Hypothyroidism Screening Results with Affected Neonates

“…According to the national data obtained from newborn thyroid screening programs, the incidence rate in Iran is one per 1400 live births (7). Different prevalence rates of congenital hypothyroidism have been reported in domestic studies: one for every 293 live births in Kerman (3), one for every 313 live births in Fars Province from 2013 to 2016 (8), one for every 417 live births in Isfahan (9), one for every 542 live births in Gilan from 2006 to 2010 (10), and one for every 1250 live births in Hamedan from 2006 to 2013 (7).…”