L-Thyroxine Supplementation for Preterm Newborns Less Than 32 Weeks of Gestation With Hypothyroxinemia

Transient hypothyroxinemia of prematurity (THOP) is associated with neurodevelopmental impairment in preterm newborns \< 32 weeks of gestation (WG). It is not known whether L-Thyroxine supplementation for preterm newborns \<32 WG with THOP is beneficial. The purpose of this study is to compare L-thyroxine treatment vs. placebo in newborn less than 32 WG with THOP. The primary endpoint is the neurodevelopmental outcome at two years of life, assessed by the Brunet-Lézine score. The secondary endpoints are: death, bronchopulmonary dysplasia (oxygen therapy at 28 days of life and at 36 weeks of postnatal age), patent ductus arteriosus, shock requiring fluid loading or vasoactive treatments, enterocolitis, intraventricular hemorrhage, retinopathy of prematurity, deafness.