Neurodevelopmental Outcomes at 42 Months After Thyroxine Supplementation in Infants Below 28 Weeks' Gestation: A Randomized Controlled Trial.

Infants below 28 weeks' gestation have low thyroid hormone plasma levels compared with more mature infants and this may contribute to their risk of developmental disability. We aimed at determining the effect of supplementation with levothyroxine (LT4) for extremely premature infants born below 28 weeks' gestations on neurodevelopmental outcomes at 42 months. An explanatory double-blind, randomized, placebo-controlled trial consecutively recruited 153 infants below 28 weeks' gestation from 5 neonatal units in the United Kingdom.

Do maternal factors influence neonatal thyroid status in the extreme premature infant?

Background: In early pregnancy, maternal transfer of thyroxine (T4) significantly contributes to the foetal T4 requirements. Interruption of the maternal transfer of T4 may lead to inadequate T4 exposure, potentially leading to neurodevelopmental deficits.

Aim: To determine if maternal factors are associated with the thyroid hormone status of extremely premature infants during the first five days of life.

Effect of thyroxine on brain microstructure in extremely premature babies: magnetic resonance imaging findings in the TIPIT study.

Background: In order to assess relationships between thyroid hormone status and findings on brain MRI, a subset of babies was recruited to a multi-centre randomised, placebo-controlled trial of levothyroxine (LT4) supplementation for babies born before 28 weeks' gestation (known as the TIPIT study, for Thyroxine supplementation In Preterm InfanTs). These infants were imaged at term-equivalence.

Materials And Methods: Forty-five TIPIT participants had brain MRI using diffusion tensor imaging (DTI) to estimate white matter development by apparent diffusion coefficient (ADC), fractional anisotropy (FA) and tractography metrics of number and length of streamlines.

An explanatory randomised placebo controlled trial of levothyroxine supplementation for babies born <28 weeks' gestation: results of the TIPIT trial.

Background: Babies born before 28 weeks' gestation have lower plasma thyroid hormone concentrations than more mature infants. This may contribute to their risk of poor developmental outcome. Previous studies have suggested that thyroxine supplementation for extremely preterm neonates may be beneficial.