No Association Between Transient Hypothyroxinemia of Prematurity and Neurodevelopmental Outcome in Young Adulthood

• Published in: The journal of clinical endocrinology and metabolism Vol. 100; no. 12; pp. 4648 - 4653
• Main Authors: Hollanders, Jonneke J, Israëls, Joël, van der Pal, Sylvia M, Verkerk, Paul H, Rotteveel, Joost, Finken, Martijn J. J
• Format: Journal Article
• Language: English
• Published: United States Endocrine Society 01-12-2015; Copyright by The Endocrine Society
• Subjects: Cohort Studies; Congenital Hypothyroidism - complications; Congenital Hypothyroidism - epidemiology; Developmental Disabilities - epidemiology; Developmental Disabilities - etiology; Female; Follow-Up Studies; Humans; Infant, Extremely Premature; Infant, Low Birth Weight; Infant, Newborn; Infant, Premature; Infant, Small for Gestational Age; Intelligence Tests; Male; Nervous System Diseases - epidemiology; Nervous System Diseases - etiology; Neuropsychological Tests; Psychomotor Performance; Thyroxine - blood; Thyroxine - deficiency; Young Adult
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2015-3078

Context:
Transient hypothyroxinemia of prematurity (THoP) has been associated with neurodevelopmental impairment in infancy and childhood. It is not known whether these relations persist into adulthood.
Objective:
The objective was to examine whether there is an effect of THoP on intelligence quotient (IQ) score and motor functioning at a young adult age.
Design:
This study was part of the 19-year follow-up of the Project On Preterm and Small-for-gestational-age birth (POPS) cohort, which included infants born very preterm (ie, <32 wk) and/or with a very low birth weight (ie, <1500 g).
Setting:
This was a multicenter study.
Patients:
There were 398 19-year-old participants of the POPS cohort, of whom 120 had THoP.
Exposure:
T4 concentrations were obtained through the national neonatal screening program for congenital hypothyroidism. THoP was defined as a total T4 concentration < −3 SD of the daily mean (approximately 60 nmol/L).
Main Outcome Measures:
Main outcome measures were IQ and motor functioning, measured with the digital Multicultural Capacities Test-Intermediate Level and a revised version of Touwen's examination of minor neurological dysfunction, respectively.
Results:
THoP was not associated with IQ score (mean difference, 0 [95% confidence interval, −3.8 to 3.8] points) or motor function (mean difference, 0.6 [95% confidence interval, −1.3 to 2.5] points) after adjustment for demographic and perinatal characteristics.
Conclusions:
No associations between THoP and neurodevelopmental outcome at age 19 years were found.