title: The second wave of the Controlled Antenatal Thyroid Screening (CATS II) study: the cognitive assessment protocol.
abstract: BACKGROUND
  Children whose mothers had low thyroid hormone levels during pregnancy have been reported to have decreased cognitive function. The reported research is part of the follow-on study of the Controlled Antenatal Thyroid Screening Study (CATS I), a randomised controlled trial which investigated the impact of treated vs. untreated low thyroid hormone level in women during pregnancy with the primary outcome being the child's IQ at age 3. No significant differences in IQ were found between the treated and untreated groups. These children are now aged between 7 and 10 years and aspects of their cognitive functioning including their IQ are being reassessed as part of CATS II.
  
  
  METHODS
  Cognitive assessments generate an IQ score and further tests administered will investigate long term memory function and motor coordination. The aim is to complete the assessments with 40% of the children born to mothers either in the treated or untreated low thyroid hormone groups (n = 120 per group). Also children born to mothers who had normal thyroid functioning during CATS I are being assessed for the first time (n = 240) to provide a comparison. Assessments are conducted either in the research facility or the participant's home.
  
  
  CONCLUSIONS
  The study is designed to assess the cognitive functioning of children born to mothers with low thyroid hormone levels and normal thyroid functioning during pregnancy. This is the largest study of its type and also is distinguishable in its longitudinal design. The research has the potential to have a significant impact on public health policy in the UK; universal screening of thyroid hormone levels in pregnancy may be the recommendation.
authors.affiliation: Thyroid Research Group, Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK. halesc2@cardiff.ac.uk.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Hales
authors.forename: Sue
authors.initials: S
authors.lastname: Channon
authors.forename: Peter N
authors.initials: PN
authors.lastname: Taylor
authors.forename: Mohd S
authors.initials: MS
authors.lastname: Draman
authors.forename: Ilaria
authors.initials: I
authors.lastname: Muller
authors.forename: John
authors.initials: J
authors.lastname: Lazarus
authors.forename: Ruth
authors.initials: R
authors.lastname: Paradice
authors.forename: Aled
authors.initials: A
authors.lastname: Rees
authors.forename: Dionne
authors.initials: D
authors.lastname: Shillabeer
authors.forename: John W
authors.initials: JW
authors.lastname: Gregory
authors.forename: Colin M
authors.initials: CM
authors.lastname: Dayan
authors.forename: Marian
authors.initials: M
authors.lastname: Ludgate
mesh_terms: D000328:Adult; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007360:Intelligence; D007361:Intelligence Tests; D007455:Iodine / Q000172:deficiency*; D008137:Longitudinal Studies; D008297:Male; D009048:Motor Skills; D011247:Pregnancy; D011248:Pregnancy Complications / Q000378:metabolism*; D011296:Prenatal Diagnosis / Q000379:methods; D013960:Thyroid Function Tests; D013963:Thyroid Hormones / Q000172:deficiency*; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D013963:Thyroid Hormones; D007455:Iodine