Your new experience awaits. Try the new design now and help us make it even better

ORIGINAL RESEARCH article

Front. Endocrinol.

Sec. Pediatric Endocrinology

Volume 16 - 2025 | doi: 10.3389/fendo.2025.1616748

Screening of 50,539 Newborns for Congenital Hypothyroidism: Optimization of TSH Cut-off Values and Seasonal Impact in Clinical Practice

Provisionally accepted
  • Affiliated Hospital of Putian University, Putian, China

The final, formatted version of the article will be published soon.

To analyze the incidence of congenital hypothyroidism (CH) in Putian, optimize the thyroid-stimulating hormone (TSH) screening cut-off value, and improve diagnostic efficiency and accuracy. Methods: A retrospective analysis was conducted on TSH screening data from 50,539 newborns in Putian between July 2020 and November 2022. TSH concentrations in dried blood spots were measured using time-resolved fluorescence immunoassay (TRFIA). The optimal cut-off value was evaluated using percentile analysis and receiver operating characteristic (ROC) curves. Confirmatory tests included serum TSH, free thyroxine (FT4), and thyroid ultrasound. Results: The detection rate of CH was 1:1,232 (41 cases), with an overall detection rate of 1:555 (including 50 cases of hyperthyrotropinemia). The P99 percentile method determined a TSH cut-off of 11.1 μIU/mL, while ROC curve analysis indicated an optimal cut-off range of 9.33-9.43 μIU/mL (sensitivity 100%, specificity 98.1%, area under the curve [AUC] = 0.997, P < 0.0001). Adopting a revised cut-off of 9.5 μIU/mL reduced recall rates by 10.62% but missed 1 case of hyperthyrotropinemia. Initial TSH positivity exhibited seasonal fluctuations, with higher rates in winter than summer. Among 68 initially negative cases with subsequent elevated venous TSH, 2 were confirmed as CH, highlighting the need for secondary screening in high-risk groups.A TSH cut-off of 9.5 μIU/mL optimizes CH screening in Putian, balancing sensitivity (100%) and specificity (98.1%). Seasonal TSH variations and high-risk cases (e.g., preterm infants) highlight the need for tailored protocols. This approach improves screening efficiency and reduces recalls, supporting region-specific adjustments.

Keywords: Newborn disease screening, Congenital Hypothyroidism, Thyroid-stimulating hormone (TSH), Cut-off optimization, Seasonal impact

Received: 23 Apr 2025; Accepted: 26 May 2025.

Copyright: © 2025 Zhang, Lin and Han. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Lixian Zhang, Affiliated Hospital of Putian University, Putian, China

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.