Preterm yenidoğanlarda gebelik yaşına göre küçük olmak ile tiroid fonksiyon testleri arasındaki ilişki

Abstract

Purpose: The aim of this study was to evaluate the relationship between thyroid hormone levels and clinical outcomes in preterm, small for gestational age (SGA) infants. Materials and Methods: The premature newborns (gestational age of ≤30 weeks) were divided into two groups as SGA and non-SGA. Thyroid stimulating hormone (TSH) and free thyroxine (fT4) levels, the frequency of congenital hypothyroidism (CH), demographic and clinical characteristics, morbidity and mortality rate were compared between the groups. Results: A total of 430 premature newborns, 72 in the SGA group and 358 in the non-SGA group were included. The frequency of CH, morbidity, demographic and clinical characteristics were similar between two groups. The mortality rate was higher in SGA (36.1%) than in non-SGA group (13.6%). Serum fT4 level was lower in SGA group (1.04±0.30 ng/dl) compared to the non-SGA group (1.24±0.33 ng/dl). The serum TSH level was higher in SGA group (9.91 ± 5.6 uIU/L) than in non-SGA group (6.6 ± 5.2 uIU/L). Conclusion: The frequency of thyroid dysfunction was higher in preterm SGA infants compared to non-SGA, which was due to transiently high TSH and low fT4 concentrations. Therefore, thyroid function tests should be monitored periodically in preterm and SGA infants.