ESPE Abstracts

Object&idot;ves: In congenital primary hypothyroidism, the effect of treatment on thyroid volume is not known. In this study, the change in thyroid volume according to etiology and its effect on treatment discontinuation rates in the treatment of congenital primary hypothyroidism were investigated.

Mater&idot;als and Methods: The clinical features and thyroid ultrasonography findings at the time of diagnosis and at the age of three years of 207 patients with congenital primary hypothyroidism were evaluated.

Results: At diagnosis, the thyroid of the patients was 64.3% (n:133) normal, 16.9% (n:35) hyperplastic, 10.1% (n:21) agenetic, 4.8% (n:10) hypoplastic, 2.4% (n:5) ectopic, 1.4% (n:3) hemiagenetic. However, at the age of three, the thyroids of the patients were 75.8% (n:157) normal, 8.2% (n:17) hyperplastic, 10.1% (n:21) agenetic, 1.9% (n:4) hypoplastic, %2,4 (n:5) ectopic, 1.4% (n:3) hemiagenesic. There was no significant difference in thyroid volumes of patients with normal thyroid volume at the time of diagnosis with treatment (p:0.305), and the rate of discontinuation of treatment at the age of three was 78.6%. The median thyroid volume of patients with hyperplastic thyroid at diagnosis decreased by 3.54 SDS with treatment (p:0.0001) and the rate of discontinuation of treatment at the age of three was 85%. The rate of discontinuation of treatment was not different between those whose thyroid volume returned to normal and those whose hyperplasia continued (p: 0.430). An increase in thyroid volume SDS (median 1.12 SDS) was observed in all patients with hypoplasia at diagnosis (p:0.005). After 3 years of treatment, 70% of patients who were hypoplastic at diagnosis had normal thyroid size and the success rate of treatmentdiscontinuation was 50%.

Conclusion: In our study, in which the effect of congenital hypothyroidism treatment on thyroid volume was evaluated for the first time, it was found that the effect of treatment on thyroid volume varied according to thyroid pathology. While there was no significant change in thyroid volume SDS with treatment in patients with normal thyroid gland at diagnosis, a significant decrease was observed in patients with thyroid gland hyperplasia at diagnosis, and a significant increase in patients with hypoplasic thyroid gland at diagnosis. In conclussion, in patients with congenital primary hypothyroidism, even if the thyroid gland is hyperplastic or hypoplastic, there may be an improvement in volume over time and drug discontinuation may be possible.