Thyroidfunctionvalues ininfantsunder 32 weeksor 1500 gr

Introduction and purpose: Thanks to the developments in the neonatal and perinatal areas, the survival rates of preterm babies have increased. Supportive treatments and follow-ups should be carried out carefully in order for these babies to have a more comfortable life without sequelae. One of them is thyroid hormone monitoring and treatment when necessary. The effects of thyroid hormones on neuromotor development are very important. Thyroid hormones are affected in premature babies due to immaturity of the hypothalamo-hypophyseal thyroid axis, infant and maternal morbidity, and drugs used. : With the technological developments, medical developments, and increased knowledge in neonatal intensive care units, the possibility of survival in premature babies has increased. In our study to determine the reference range of thyroid hormone values in the postnatal 1st and 3rd weeks of premature babies, it was found that there was a correlation between the gestational week and birth weight and thyroid hormone values. It was determined that different reference intervals should be used for babies with low birth weight and gestational week. It was determined that the demographic characteristics of the mother had no effect on the thyroid hormones of the baby. Since transient TFT disorders are seen in premature babies and in order not to delay the diagnosis of CH, we believe that serial TFT control should be performed by performing multicenter prospective studies.