ESPE Abstracts

Background: In the world, the incidence of congenital hypothyroidism varies in wide ranges. In the neonatal screening based on thyroid-stimulating hormone (TSH), the optimal diagnostic level of TSH is essential to ensure that the true cases of congenital hypothyroidism are not missed.

The goal was to compare the incidence rate of congenital hypothyroidism during the course of changes in the screening protocol for the periods of 2003-2007 and 2008-2017.

Materials and Methods: During 2003-2007, the diagnostic level of TSH from capillary blood on the 4th-5th day was > 20 microU/ml of whole blood, then a repeated serum retest was recommended on the day 15. Congenital hypothyroidism was diagnosed at TSH level > 10 microu/ml, and it was recommended to start an immediate treatment with thyroxine.

During 2008–2017, the protocol was changed: the recommended diagnostic level of TSH from capillary blood on day 4–5 was > 10 microU/ml of whole blood, after which the retest from blood serum on day 15 was prescribed. If the serum TSH level was > 5 microU/ml, then it was necessary to immediately begin treatment with thyroxine.

Results: A total of 313,970 newborns were examined in the Republic of Karakalpakstan. During 2003–2007, the incidence of congenital hypothyroidism in the region was 1:3185, whilst in Uzbekistan it was 1:2350. After changing the screening protocol, in the years of 2008-2017, the incidence of congenital hypothyroidism in Karakalpakstan leveled at 1:2280, and in the country overall at 1:3215. For the entire period, 129 children with congenital hypothyroidism were identified in Karakalpakstan. In their third year of life, 95 were left registered, 25 children were taken off the registry due to transient hypothyroidism, 3 left, and 3 died.

Conclusions: It was revealed that the incidence of congenital hypothyroidism in Karakalpakstan is higher than in Uzbekistan as a whole. Changing the screening protocol improved the diagnosis of the disease.