Physical Development at School Entry in Children with Congenital Hypothyroidism Diagnosed by the National Program of Newborn Screening in Iran.

Background: The newborn screening program for diagnosing and treating children with congenital hypothyroidism (CH) in Iran was established in 2004.

Objectives: This study aimed to evaluate the national program's success in maintaining the physical development and anthropometric indexes of children with CH.

Methods: This historical cohort study was carried out in five provinces located in five different geographical regions of Iran. The anthropometric indexes, including weight, height, and head circumference of 240 children diagnosed with transient congenital hypothyroidism (TCH) (n = 131) and permanent congenital hypothyroidism (PCH) (n = 109) were measured and compared with those of 240 healthy children aged six.

Results: Mean ± standard deviation (SD) of weight, height, and head circumference of children with CH aged six were 20304.8 ± 4457.9 g, 115.6 ± 5.9 cm, and 50.8 ± 1.7 cm, respectively. Mean ± SD of height (116.7 ± 6.1 cm) and head circumference (51.1 ± 1.7 cm) in the control (healthy) group were significantly higher than those of the CH children group (P < 0.05). Mean ± SD weight in the control group (20741.2 ± 4337.3 g) was higher than that in the CH group (20304.8 ± 4457.9 g). However, the difference was not statistically significant (P = 0.3). No significant difference was observed between TCH and PCH children in the subgroup analysis (P > 0.05).

Conclusions: Although the mean of anthropometric indexes in CH patients was slightly lower than that in healthy children aged six, the difference between the two groups was insignificant. The physical development of children with CH was evaluated as good. Our results suggested that the newborn screening program for identifying and treating children with CH in Iran may have improved the growth outcomes.