title: Efficacy of congenital hypothyroidism neonatal screening in preterms less than 32 weeks of gestational age: more evidence.
abstract: OBJECTIVE
  To evaluate the double screening performed for congenital hypothyroidism (CH) to preterm infants <32 weeks of gestational age (GA) between 1994 and 2003.
  
  
  METHODS
  TSH was assessed by IFMA. Infants were classified as: term (T) (>37 weeks GA); preterm (PT) (33-37 weeks GA); and very preterm (VPT) (< or =32 weeks GA).
  
  
  RESULTS
  In 585,221 screened infants, CH was confirmed in 228 T, 23 PT and seven VPT. An increasing incidence of CH was found with decreasing GA, affecting 1:1,603 PT and 1:585 VPT. PT infants had 1.5 times more risk than full-term infants of suffering CH, and VPT 4 times more. Only 4/7 affected VPT had an adequate double screening as requested. Three had elevated TSH values in the first sample and in one a normal TSH (10.3 mIU/l) at 3 days rose to 240 mIU/l after day 15. In the remaining three VPT, TSH in the unique filter paper sample (21 to 34 days) was markedly elevated.
  
  
  CONCLUSIONS
  Our findings reinforce the need for awareness in neonatal settings for adequate screening of VPT infants. Screening in the first week of life was effective in detection of most but not all affected VPT. Larger studies are needed in order to establish accurate screening recommendations for VPT newborns. Until this step is reached, repeated screening is advised in these infants.
authors.affiliation: Fundación de Endocrinologia Infantil, Buenos Aires, Argentina. lauragru@cedie.org.ar
authors.forename: Laura
authors.initials: L
authors.lastname: Gruñeiro-Papendieck
authors.forename: Ana
authors.initials: A
authors.lastname: Chiesa
authors.forename: Virginia
authors.initials: V
authors.lastname: Mendez
authors.forename: Alexia
authors.initials: A
authors.lastname: Santilli
authors.forename: Laura
authors.initials: L
authors.lastname: Prieto
mesh_terms: D003409:Congenital Hypothyroidism; D005865:Gestational Age; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis*; D007231:Infant, Newborn; D007234:Infant, Premature; D015997:Neonatal Screening / Q000592:standards*; D012189:Retrospective Studies