title: Mild maternal thyroid dysfunction at delivery of infants born ≤34 weeks and neurodevelopmental outcome at 5.5 years.
abstract: BACKGROUND
  Mild maternal thyroid dysfunction during early pregnancy is associated with poor neurodevelopment in affected offspring. Most studies are population based or are smaller populations of term/late preterm infants. No studies were found that focused on more preterm infants.
  
  
  OBJECTIVE
  Our objective was to describe the relationship between mild maternal thyroid dysfunction at delivery of infants born ≤34 wk and neurodevelopment at 5.5 yr.
  
  
  METHODS
  The study design was follow-up of women and children recruited in Scotland between 1998 and 2001.
  
  
  RESULTS
  We evaluated delivery levels of maternal TSH, free T(4) (FT(4)), and T(4) and the association with McCarthy Scale scores adjusted for 26 confounders of neurodevelopment.
  
  
  RESULTS
  Maternal serum levels and McCarthy scores were available for 143 women and 166 children. After adjustment for confounders, there were significant 3.2, 2.1, and 1.8 point decrements, respectively, in general cognitive index, verbal subscale, and the perceptual performance subscale for each milliunit per liter increment in maternal TSH. Maternal FT(4) levels were variably associated with neurodevelopment. After adjustment, significant associations were found for the general cognitive index, motor scale, and quantitative subscale; each picomole per liter decrease in FT(4) was associated with an increase of 1.5, 1.7, and 0.9 points, respectively. Maternal T(4) levels showed little relationship with neurodevelopment. None of the women in this analysis had overt hypothyroidism, but mild hypothyroidism was evident in 27%; thyroglobulin antibody (TgAb) was ≥ 40 U/ml in 28% of the women.
  
  
  CONCLUSIONS
  Higher maternal levels of TSH at delivery of infants born preterm were associated with significantly lower scores on the general cognitive index at 5.5 yr.
authors.affiliation: Population Health Sciences, Mackenzie Building, University of Dundee, Ninewells Hospital and Medical School Campus, Kirsty Semple Way, Dundee DD2 4BF Scotland, United Kingdom. f.l.r.williams@dundee.ac.uk
authors.forename: Fiona
authors.initials: F
authors.lastname: Williams
authors.forename: Jennifer
authors.initials: J
authors.lastname: Watson
authors.forename: Simon
authors.initials: S
authors.lastname: Ogston
authors.forename: Robert
authors.initials: R
authors.lastname: Hume
authors.forename: Peter
authors.initials: P
authors.lastname: Willatts
authors.forename: Theo
authors.initials: T
authors.lastname: Visser
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood; D001921:Brain / Q000254:growth & development* / Q000502:physiology; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D003071:Cognition / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development* / Q000502:physiology; D007453:Iodide Peroxidase / Q000276:immunology; D008297:Male; D011247:Pregnancy; D047928:Premature Birth / Q000503:physiopathology*; D011297:Prenatal Exposure Delayed Effects / Q000503:physiopathology*; D012720:Severity of Illness Index; D013954:Thyroglobulin / Q000276:immunology; D013959:Thyroid Diseases / Q000097:blood / Q000503:physiopathology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D013972:Thyrotropin; D013954:Thyroglobulin; D007453:Iodide Peroxidase; D013974:Thyroxine