Neurodevelopmental outcomes in children with transient hypothyroxinemia of prematurity assessed using the Denver...

This study aimed to evaluate the impact of levothyroxine supplementation on neurodevelopmental outcomes in infants with transient hypothyroxinemia of prematurity (THOP).

In this retrospective observational study, infants born at < 34 weeks of gestation were categorized into three groups: THOP treated with levothyroxine, untreated THOP, and non-hypothyroxinemic controls. Neurodevelopmental outcomes were assessed at 12-72 months of corrected age using the Denver Developmental Screening Test II (DDST-II).

Fifty-four infants (40.7% female) with a median gestational age (GA) of 31.0 (28.6-33.0) weeks and mean birth weight of 1414 ± 466 g were included. Infants treated for THOP had significantly lower GA compared with controls (p = 0.037) and lower initial FT4 levels (p < 0.001), while TSH levels were similar (p = 0.581). Prematurity-related morbidities were more frequent in the treated THOP group. No association was observed between DDST-II results and GA, birth weight, or prematurity-related morbidities. The DDST-II results did not differ significantly among treated THOP, untreated THOP, and controls (p = 0.484).

Levothyroxine supplementation in infants with THOP was not associated with neurodevelopmental outcomes compared with untreated infants with THOP or non-hypothyroxinemic controls. In this cohort, DDST-II results were not significantly associated with GA, birth weight, or major prematurity-related morbidities, suggesting that routine levothyroxine supplementation may not confer a measurable neurodevelopmental benefit. Given the observational design and baseline clinical differences between groups, these findings should be interpreted cautiously. Further multicenter studies with larger cohorts and comprehensive follow-up are needed to clarify whether specific high-risk subgroups may benefit from treatment..