First results of neonatal screening for congenital hypothyroidism during the transition to early blood sampling in newborns

Abstract

In Krasnodar region neonatal screening (NS) for congenital hypothyroidism (CH) has been carried out since 1994; blood sampling from children was carried out on days 4-5 of life. It was of interest to evaluate the effectiveness of NS on CH in connection with the transition to early blood sampling in newborns. 101,445 children born from 1/1/23 to 12/31/24 were examined for CH: at the age of the first 2 days of life (group 1) – 93,431 (92.1%), at the age of 3-14 days of life (group 2) – 8,014 (7.9%). The threshold blood TSH level for children in group 1 was 10.2 µIU/ml, in group 2 – 8.52 µIU/ml. The average blood TSH level in group 1 was 3.23+3.4 µIU/ml, in group 2 – 2.15+5.4 µIU/ml.An increase in primary hyperthyrotropinemia was noticed in 2023-2024: 1.29% in group 1 and 1.49% in group 2. CH was diagnosed in 45 newborns (1:2254 newborns).Analysis of the results of NS on VH showed an increase in the threshold blood TSH level when examining children in the first 24-48 hours of life compared to the threshold TSH level during a later examination. Thus, changing the timing of examination of newborns during NS requires careful consideration of TSH threshold levels to prevent unnecessary retests.