Lenore DeMartino1, Rebecca McMahon1, Michele Caggana1, Norma P Tavakoli1,2. 1. Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, New York, USA. 2. Department of Biomedical Sciences, School of Public Health, State University of New York, Albany, New York, USA.
Abstract
OBJECTIVE: Newborn screening for congenital hypothyroidism (CH) is based on testing for the markers thyroxine (T4) and/or thyroid-stimulating hormone (TSH). Diagnosis of CH is complicated because many factors affect the levels of these hormones including infant birth weight, prematurity and age at specimen collection. We investigated whether the sex of the newborn affected the levels of T4 and TSH and consequently the outcome of newborn screening. DESIGN: In New York State, the Newborn Screening program initially tests all infants for T4 and any baby with a result in the lowest 10% is triaged for TSH screening. We analyzed data from 2008 to 2016 to determine mean and median T4 and TSH values and how these results correlate with the sex of infants who are reported as borderline, referred and confirmed with CH. METHODS: T4 and TSH concentrations in dried blood spots were measured using commercially available fluoroimmunoassays. RESULTS: From 2008 to 2016, of the 2.4 million specimens tested for thyroxine, 51.5% were from male and 48.5% were from female infants. Male infants constituted 60% of specimens triaged for TSH testing, 64.9% of repeat requests and 59.6% of referrals, but only 49% of confirmed CH cases. The mean and median T4 values were lower (a difference of approximately 0.8-1.1 μg/dL each year) and the median TSH values were higher in male compared to female infants. CONCLUSIONS: Natural differences in thyroid hormone levels in male and female infants leads to male infants being disproportionately represented in the false-positive category.
OBJECTIVE: Newborn screening for congenital hypothyroidism (CH) is based on testing for the markers thyroxine (T4) and/or thyroid-stimulating hormone (TSH). Diagnosis of CH is complicated because many factors affect the levels of these hormones including infant birth weight, prematurity and age at specimen collection. We investigated whether the sex of the newborn affected the levels of T4 and TSH and consequently the outcome of newborn screening. DESIGN: In New York State, the Newborn Screening program initially tests all infants for T4 and any baby with a result in the lowest 10% is triaged for TSH screening. We analyzed data from 2008 to 2016 to determine mean and median T4 and TSH values and how these results correlate with the sex of infants who are reported as borderline, referred and confirmed with CH. METHODS: T4 and TSH concentrations in dried blood spots were measured using commercially available fluoroimmunoassays. RESULTS: From 2008 to 2016, of the 2.4 million specimens tested for thyroxine, 51.5% were from male and 48.5% were from female infants. Male infants constituted 60% of specimens triaged for TSH testing, 64.9% of repeat requests and 59.6% of referrals, but only 49% of confirmed CH cases. The mean and median T4 values were lower (a difference of approximately 0.8-1.1 μg/dL each year) and the median TSH values were higher in male compared to female infants. CONCLUSIONS: Natural differences in thyroid hormone levels in male and female infants leads to male infants being disproportionately represented in the false-positive category.
Authors: Ali S Alzahrani; Mourad Al Mourad; Kevin Hafez; Abdulrahman M Almaghamsy; Fahad Abdulrahman Alamri; Nasser R Al Juhani; Alhussien Sagr Alhazmi; Mohammad Yahya Saeedi; Saud Alsefri; Musa Daif Allah Alzahrani; Nadia Al Ali; Wiam I Hussein; Mohamed Ismail; Ahmed Adel; Hisham El Bahtimy; Eslam Abdelhamid Journal: Adv Ther Date: 2020-06-01 Impact factor: 3.845