Neurodevelopmental outcomes in children with transient hypothyroxinemia of prematurity assessed using the Denver Developmental Screening Test II (DDST-II)

Creative Commons License

Ozer Y., Yilmaz A., Yilmaz G., Sari A. A., Turan H., Tarcin G., ...More

ARCHIVES OF ENDOCRINOLOGY METABOLISM, vol.70, no.5, 2026 (SCI-Expanded, Scopus)

Abstract

Objective: This study aimed to evaluate the impact of levothyroxine supplementation on neurodevelopmental outcomes in infants with transient hypothyroxinemia of prematurity (THOP). Subjects and methods: 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). Results: 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). Conclusion: 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..