Assessing growth parameters of children with congenital hypothyroidism subject to levothyroxine treatment compared to normal growth parameters in healthy newborns

Background and aims: Congenital hypothyroidism (CH) is one of the most common treatable physical growth disorders leading to mental retardation. Most cases of this disease can be detected through the neonatal screening program. Given the high prevalence of this disease and the implementation of screening programs in recent years in Iran, this study aimed to assess the growth indices of newborns with CH. Methods: In this retrospective cohort study, 66 newborns with CH detected in the screening program in Shahrekord were selected by a census sampling method. Overall, 125 healthy newborns were also selected as controls by the convenience sampling technique according to the inclusion and exclusion criteria. The height, weight, head circumference, and body mass index (BMI) of the samples were measured and then the mean, median, standard deviation, as well as the 3rd, 15th, 25th, 50th, 75th, 85th, and 97th percentiles in the two groups were determined and compared based on gender and age group. Results: The height, weight, head circumference, and BMI of the boys, in addition to the head circumference and BMI of the girls, were not significantly different from those of the controls (P 0.05). However, the height and weight of the girls were significantly lower compared to those in the control group, although the difference in the weight was corrected at the age of 9 months. Conclusion: In general, the growth indices of newborns with CH were lower than those of the controls. This difference was significant only for the weight and height of girls with CH.