Postnatal thyroxine supplementation in infants less than 32 weeks' gestation: effects on pulmonary morbidity

Transient hypothyroxinemia in premature newborns has been linked with poor neonatal outcomes. We designed this study to evaluate the effects of early thyroxine (T4) administration in the premature infant.

A total of 49 newborns less than 32 weeks' gestation, were randomized in a double-blind, placebo-controlled trial. Within the first 48 hours of life, T4 (10 or 20 micrograms/kg; intravenous or through nasogastric tube, respectively) was administered for a total of 21 days. Chronic lung disease, the primary outcome variable, was defined by oxygen dependency at 28 days of life.

The incidence of chronic lung disease, death, grade III or IV intraventricular hemorrhage, periventricular leukomalacia, and sepsis was not different in the placebo and treated groups.

Early T4 supplementation in preterm newborns less than 32 weeks' gestation does not decrease the incidence of chronic lung disease or other complications of prematurity.