BSPED2014 Poster Presentations (1) (88 abstracts)
1Department of Clinical Biochemistry Central Manchester Foundation Trust, Manchester, UK; 2Department of Paediatric Endocrinology Royal Manchester Childrens Hospital, Manchester, UK.
Background: The UK Newborn Screening Programme Centre Clinical Referral Standards and Guidelines for CHT (2013) define TSH cut-offs for screen positive (>20 mU/l) and borderline (>10 and <20 mU/l) results. In Manchester levels >8 and <20 mU/l are classified as borderline. This audit aims to assess whether adopting the national cut-off would result in babies with significant and permanent hypothyroid disease being missed.
Patient population: All babies screened by the Manchester laboratory from October 2007 to April 2014,
Audit methodology: A search of the laboratory screening information system identified all babies with an initial TSH result of >8 and <10 mU/l and a repeat TSH of >8 mU/l. Diagnostic test results and details of thyroxine therapy were obtained on this cohort and in confirmed cases now >2 years of age we attempted to ascertain whether thyroxine therapy was continuing and if thyroid status had been reassessed after 46 weeks off therapy as guidelines recommend.
Results: 399 babies had an initial TSH of >8 mU/l and <10 mU/l and 19 of those had a valid repeat TSH >8 mU/l. A diagnosis was confirmed in 17/19 and all were commenced on Thyroxine. There was no evidence on thyroid imaging of an absent or ectopic thyroid in any of the cases. 11/19 babies are now >2 years and follow-up data has so far been obtained in 4/11. In 2/4 permanent CHT is confirmed, 1/4 was transient and has ceased thyroxine and 1/4 remains on thyroxine but has not been re-tested.
Conclusion: In Manchester adoption of the national borderline TSH cut-off would re-classify an average of three confirmed cases CHT/year as normal. Work is on-going to establish the proportion of these babies in whom hypothyroidism is permanent.