title: Screening for congenital hypothyroidism in newborns transferred to neonatal intensive care.
abstract: OBJECTIVE
  To evaluate the effectiveness of four dried blood spot testing protocols used in newborn screening for congenital hypothyroidism (CH) among newborns transferred to the neonatal intensive care unit (NICU).
  
  
  METHODS
  Michigan newborns transferred to the NICU from 1998 to 2011 and screened for CH are included in this population-based retrospective cohort study.
  
  
  METHODS
  Screening performance metrics are computed and logistic regression is used to test for differences in the likelihood of detection across four periods characterised by different testing protocols.
  
  
  RESULTS
  Primary thyrotropin (TSH) plus retest at 30 days of life or discharge achieved the greatest detection rate (2.6: 1000 births screened). The odds of detection was also significantly greater in this period compared with the tandem thyroxine (T4) and TSH testing period and separately compared with TSH testing alone, adjusted for birth weight, sex and race (OR 1.5; CI 1.0 to 2.2; p=0.046, and OR 2.2; CI 1.5 to 3.4, respectively). Approximately half of the cases detected during primary TSH plus serial testing periods were identified by retest.
  
  
  CONCLUSIONS
  Primary TSH testing programmes that do not incorporate serial screening may fail to identify approximately half of newborns with congenital thyroid hormone deficiency transferred to the NICU. Tandem T4 and TSH testing programmes also likely miss cases who otherwise would receive treatment if serial testing were conducted. Further research is necessary to determine the optimal newborn screening protocol for CH; strategies combining tandem T4 and TSH with serial testing conditional on birthweight may be useful.
authors.affiliation: Perinatal Epidemiology Unit, Perinatology Research Branch (NICHD/NIH), and Department of Obstetrics & Gynecology, Wayne State University School of Medicine, Detroit, MI 48201, USA. sKorzeni@med.wayne.edu
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Korzeniewski
authors.forename: Mary
authors.initials: M
authors.lastname: Kleyn
authors.forename: William I
authors.initials: WI
authors.lastname: Young
authors.forename: Tinnakorn
authors.initials: T
authors.lastname: Chaiworapongsa
authors.forename: Alyse G
authors.initials: AG
authors.lastname: Schwartz
authors.forename: Roberto
authors.initials: R
authors.lastname: Romero
mesh_terms: D015331:Cohort Studies; D003409:Congenital Hypothyroidism / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D008824:Michigan; D015997:Neonatal Screening / Q000379:methods*; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013972:Thyrotropin / Q000097:blood* / Q000378:metabolism; D013997:Time Factors
chemical_list: D013972:Thyrotropin