Korean Journal of Pediatrics 2009;52(9):991-998.
Published online September 15, 2009.
Thyroid dysfunction in premature infants
Ki Bae Hong, Ji Yun Park, Young Pyo Chang, Jeesuk Yu
Department of Pediatrics, Dankook University College of Medicine, Cheonan, Korea
미숙아에서의 갑상선기능 장애
홍기배, 박지윤, 장영표, 유지숙
단국대학교 의과대학 소아과학교실
Correspondence: 
Jeesuk Yu, Email: dryujs@dankook.ac.kr
Abstract
Purpose
Thyroid hormone is essential for development of the brain in early life. Thyroid dysfunction is more common in the first 2-4 postnatal weeks of life in premature infants than in term infants. This study aimed to identify the prevalence and clinical course of thyroid dysfunction in prematurity.
Methods
Premature infants admitted to and given neonatal screenings at Dankook University Hospital between April 1999 and March 2008 were included in this study. We retrospectively reviewed medical records and categorized subjects into six groups: normal, hypothyroidism, hyperthyrotropinemia, hypothyroxinemia, delayed onset of hypothyroidism, and delayed onset of hyperthyrotropinemia.
Results
Among 599 subjects, 136 (23%) had initially abnormal thyroid function test (TFT); transient hypothyroxinemia was the most frequent condition (118, 20%). In addition, 8 (17%) of 46 subjects with initially normal TFT levels showed delayed onset of hyperthyrotropinemia with or without low free thyroxine (fT4). Thyroxine was prescribed for 10 patients (1.7%) due to low fT4 levels but was discontinued in 9 patients during follow-up. Thyroid scan confirmed ectopic thyroid in one patient.
Conclusion
Thyroid dysfunction was frequently seen in premature infants, but most of the conditions were transient. In addition, some infants showed delayed TSH elevation on routine follow-up. Therefore, a recheck of the thyroid function of premature infants at 3-4 weeks is recommended, even if normal thyroid function is initially seen, especially in prematurity of less than 33 weeks of gestational age or birth weight of less than 2,500 grams.
Key Words: Thyroid, Infant, Premature, Neonatal screening


METRICS Graph View
  • 2,618 View
  • 121 Download


Close layer
prev next