title: Effect of l-thyroxine supplementation on infants with transient hypothyroxinemia of prematurity at 18 months of corrected age: randomized clinical trial.
abstract: OBJECTIVE
  Our objective was to evaluate effects of levothyroxine (l-T4) supplementation against neurodevelopmental outcomes at 18 months of corrected age in very-low-birth-weight (VLBW) infants with hypothyroxinemia but without elevated thyroid-stimulating hormone (TSH) concentration.
  
  
  METHODS
  VLBW infants who had plasma TSH concentrations <10 μU/mL and free thyroxine (FT4) concentrations <0.8 ng/dL between 2 and 4 weeks of age were enrolled. They were randomly assigned to either the Treated (n=25) or Untreated group (n=45). The Treated group received l-T4 at a dose of 5 μg/kg/day. We compared growth and neurodevelopmental outcomes at 18 months of corrected age in the two groups.
  
  
  RESULTS
  There were no significant differences in growth, the incidences of developmental delay, cerebral palsy, visual impairment, and hearing impairment in the two groups.
  
  
  CONCLUSIONS
  In such infants, l-T4 supplementation at a dose of 5 μg/kg/day did not affect FT4 levels and showed no beneficial effect at 18 months of corrected age.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Uchiyama
authors.forename: Reiko
authors.initials: R
authors.lastname: Kushima
authors.forename: Toyoko
authors.initials: T
authors.lastname: Watanabe
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kusuda
mesh_terms: D002657:Child Development / Q000187:drug effects; D003409:Congenital Hypothyroidism / Q000097:blood / Q000188:drug therapy*; D005260:Female; D005865:Gestational Age; D020249:Hormone Replacement Therapy; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000097:blood / Q000188:drug therapy*; D019102:Infant, Very Low Birth Weight; D008297:Male; D013960:Thyroid Function Tests; D013974:Thyroxine / Q000097:blood / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D013974:Thyroxine