Somatosensory evoked potentials in very preterm infants in relation to L-thyroxine supplementation.

Abstract

To study the effect of L-thyroxine supplementation on neurologic maturation in very preterm infants with transient hypothyroxinemia. Randomized, double-blind, placebo-controlled, L-thyroxine supplementation trial. Level III neonatal intensive care unit. A total of 200 infants <30 weeks' gestational age. Subjects were randomly assigned to receive L-thyroxine (8 microg/kg birth weight per day) or a placebo during the first 6 weeks of life. Median nerve somatosensory evoked potentials were recorded, measuring cortical N1 peak latency at 2 weeks of age, at term, and at 6 months (corrected) age. Cortical N1 peak latency was not decreased significantly in the L-thyroxine group compared with the placebo group throughout the study period. L-Thyroxine supplementation during the first 6 weeks of life did not decrease cortical N1 peak latency in infants of <30 weeks' gestational age.