Background: Transient hypothyroxinemia of prematurity (THOP) is characterized by low thyroxine (T4) levels with normal thyroid-stimulating hormone (TSH) levels. This study aimed to determine the incidence and factors associated with THOP.
Methods: This prospective cohort study included neonates who were born before 37 weeks of gestation in the neonatal intensive care unit (NICU) between April 2017 and December 2020.