| Abstract | BACKGROUND: Revised UK neonatal screening guidelines recommend that a second blood sample for assay of thyroid stimulating hormone (TSH) be taken when preterm infants reach a postmenstrual age of 36 weeks. OBJECTIVE: To examine the results of a regional screening programme to see whether a rise in TSH concentration was observed in some preterm infants between the first sample taken around 5 days after delivery and the second sample taken at around 36 weeks. METHODS: Whole-blood TSH concentrations in preterm infants born over a 2-year period (April 2005 to March 2007) were assessed, and the number of infants in whom there was a fall or rise to values below or above the local screening threshold (6 mU/l) was determined. RESULTS: Baseline TSH samples were obtained from 2238 preterm infants (median gestational age 32 weeks, range 21-35) with second samples obtained from 2039 (median gestational 32 weeks, range 23-35). In 19 infants, TSH concentrations fell from above to below the screening threshold, and in five infants values rose from below the screening threshold to 6-10 mU/l. However, TSH concentrations fell to <6 mU/l on a further blood spot in four of these infants, and the remaining infant had a serum TSH of 6.8 mU/l. Three infants had raised TSH concentrations on both occasions with unequivocal hypothyroidism (serum TSH >80 mU/l). The initial TSH concentration in one of these infants was 6-10 mU/l. CONCLUSIONS: No infant with a normal TSH concentration on first sampling had a TSH concentration that rose above 10 mU/l on second sampling, and no infants with a normal TSH concentration on first screening are receiving long-term thyroxine treatment. This study suggests that a second sample may not be necessary with a screening threshold of 6 mU/l. |
| Authors | M Korada, M S Pearce, M P Ward Platt, E Avis, S Turner, H Wastell, T Cheetham
(Affiliation: School of Clinical Medical Sciences (Child Health), Sir James Spence Institute, Royal Victoria Infirmary, Newcastle Upon Tyne, UK.)
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| Journal | Archives of disease in childhood. Fetal and neonatal edition
(Arch Dis Child Fetal Neonatal Ed)
Vol. 93
Issue 4
Pg. F286-8
(Jul 2008)
ISSN: 1468-2052 England |
| PMID | 18252816
(Publication Type: Journal Article)
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| Chemical References |
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| Topics |
- Congenital Hypothyroidism
(diagnosis)
- Female
- Humans
- Infant, Newborn
- Infant, Premature
- Infant, Premature, Diseases
(diagnosis)
- Male
- Neonatal Screening
(methods)
- Reference Values
- Thyroid Function Tests
(methods)
- Thyrotropin
(blood)
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