title: Neonatal thyroid-stimulating hormone level is influenced by neonatal, maternal, and pregnancy factors.
abstract: The percentage of newborns with a neonatal whole blood thyroid-stimulating hormone (TSH) greater than 5 mIU/L has been used as an indicator of iodine deficiency at the population level. However, TSH levels in newborns may be influenced by many factors other than iodine status. The objective of this study was to identify neonatal, maternal, and pregnancy-related determinants of neonatal TSH levels in a retrospective cohort study. The study sample included 313 Belgian mothers and their 4- to 5-year-old children. The children had a neonatal TSH concentration between 0 and 15 mIU/L at neonatal screening, and blood samples were collected 3 to 5 days after birth. Children with suspected congenital hypothyroidism (neonatal TSH level >15 mIU/L), prematurely born (i.e., <37 weeks), or with a low birth weight (i.e., <2500 g) were excluded. Information about maternal and birth-related determinants was collected from the neonatal screening center via a self-administered questionnaire filled in by the mother together with the child's health booklet. Higher TSH levels were found in spring and winter compared to summer and autumn (P = .011). Higher TSH levels were associated with lifetime smoking behavior (up to child birth) in the mother (P = .005), lower weight gain during pregnancy (P = .014), and longer pregnancies (P = .003). This study showed that several neonatal, maternal, and pregnancy-related determinants are influencing neonatal TSH level.
authors.affiliation: Unit of Public Health and Surveillance, Scientific Institute of Public Health, 1050 Brussels, Belgium. Electronic address: Caroline.Trumpff@wiv-isp.be.
authors.forename: Caroline
authors.initials: C
authors.lastname: Trumpff
authors.affiliation: Unit of Public Health and Surveillance, Scientific Institute of Public Health, 1050 Brussels, Belgium. Electronic address: Stefanie.Vandevijvere@wiv-isp.be.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Vandevijvere
authors.affiliation: Department of Nuclear Medicine, Erasme Hospital, Free University of Brussels, 1070 Brussels, Belgium. Electronic address: rmorenor@ulb.ac.be.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Moreno-Reyes
authors.affiliation: Medical Microbiology Laboratory, Communicable and Infectious Diseases, Scientific Institute of Public Health, 1180 Brussels, Belgium. Electronic address: jean.vanderpas@wiv-isp.be.
authors.forename: Jean
authors.initials: J
authors.lastname: Vanderpas
authors.affiliation: Unit of Public Health and Surveillance, Scientific Institute of Public Health, 1050 Brussels, Belgium. Electronic address: Jean.Tafforeau@wiv-isp.be.
authors.forename: Jean
authors.initials: J
authors.lastname: Tafforeau
authors.affiliation: Unit of Public Health and Surveillance, Scientific Institute of Public Health, 1050 Brussels, Belgium. Electronic address: Herman.VanOyen@wiv-isp.be.
authors.forename: Herman
authors.initials: H
authors.lastname: Van Oyen
authors.affiliation: Department of Paediatric Endocrinology, UZ Brussel, Vrije Universiteit Brussel, 1090 Brussels, Belgium. Electronic address: Jean.DeSchepper@uzbrussel.be.
authors.forename: Jean
authors.initials: J
authors.lastname: De Schepper
mesh_terms: D000328:Adult; D001530:Belgium; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009035:Mothers; D015997:Neonatal Screening; D011247:Pregnancy; D012189:Retrospective Studies; D013972:Thyrotropin / Q000097:blood*
chemical_list: D013972:Thyrotropin
keywords: Neonatal thyroid stimulating hormone; confounding factors; iodine deficiency; newborn; pregnancy; smoking