title: Neonatal Thyroid-Stimulating Hormone Screening as a Monitoring Tool for Iodine Deficiency in Turkey.
abstract: OBJECTIVE
  Thyroid-stimulating hormone (TSH) level in neonates is recommended as an indicator for presence of iodine deficiency (ID) at a population level and as a monitoring tool in programs of iodine supplementation. The purpose of this study, based on data from the National Newborn Screening Program (NNSP) for congenital hypothyroidism (CH) in 2014, was to analyze neonatal TSH levels to predict the current status of iodine nutrition in Turkey.
  
  
  METHODS
  According to screening methodology, heel-prick blood samples of newborns were collected on filter paper cards usually on day 3-5 after birth (or shortly before discharge). Results of samples collected >48 h after birth were analyzed. The degree of severity of ID was assessed by using the epidemiologic criteria of the World Health Organization (WHO). Elevated TSH levels (>5 mIU/L) were processed and classified according to province, region, birth season, and sampling time.
  
  
  RESULTS
  A total of 1,298531 newborns were registered in the NNSP for the CH database. Of those, 1,270311 newborns had screening results collected >48 h after birth and were included in the statistical analyses. The national prevalence of elevated TSH was 7.2%. While the Gaziantep sub-region had the highest TSH elevation rate (15.9%), the Tekirdağ sub-region had the lowest rate (4.0%; p<0.001). Seasonal variations were also significant, and the elevated TSH prevalence rate was highest in winter (7.4%; p<0.001).
  
  
  CONCLUSIONS
  National CH screening results suggest that Turkey may still be mildly iodine deficient. Nationwide studies should be performed for direct assessment and monitoring of iodine status in vulnerable populations to confirm accuracy of our results.
authors.affiliation: Public Health Institution of Turkey, Department of Child and Adolescent Health, Ankara, Turkey Phone: +90 312 565 60 76 E-mail: nilgun.caylan@gmail.com.
authors.forename: Nilgün
authors.initials: N
authors.lastname: Çaylan
authors.forename: Başak
authors.initials: B
authors.lastname: Tezel
authors.forename: Sema
authors.initials: S
authors.lastname: Özbaş
authors.forename: Nuran
authors.initials: N
authors.lastname: Şahin
authors.forename: Şirin
authors.initials: Ş
authors.lastname: Aydın
authors.forename: Deniz
authors.initials: D
authors.lastname: Acıcan
authors.forename: Bekir
authors.initials: B
authors.lastname: Keskinkılıç
mesh_terms: D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007455:Iodine / Q000172:deficiency*; D008297:Male; D015997:Neonatal Screening / Q000379:methods*; D015995:Prevalence; D013959:Thyroid Diseases / Q000453:epidemiology* / Q000517:prevention & control*; D013972:Thyrotropin / Q000097:blood*; D014421:Turkey / Q000453:epidemiology
chemical_list: D013972:Thyrotropin; D007455:Iodine