Endocrine Abstracts

Introduction: UK Screening for CHT was introduced in 1981 to facilitate early detection, treatment and prevent associated morbidity and mortality. Screening in the North East and Cumbria is coordinated by the XXXXXX. A locally defined threshold of TSH >6 mU/l constitutes a positive screening test in contrast to national guidance of > 10 mU/l. We explored the longer-term outcomes of infants identified by the screening programme.

Aim: The aims of this audit were to one. Determine the outcome and final diagnosis of patients screening positive for CHT in our region, two. Establish the overall prevalence of patients with CHT in the North East and North Cumbria region, three. Determine the outcomes of infants with screening TSH levels between 6–10 mmol/l.

Methods: Full caldicott approval was obtained. All patients screened by the service born between 1 April 2005 and 1 January 2011 were included. Mean blood TSH >20 mU/l on first screen or >6 mU/l in those subject to repeat testing in the 6–20 range constituted a positive result. Case notes of identified patients were reviewed.

Results: 107 patients screened positive on first or repeat testing. We obtained results for 93 patients. 76% patients receiving thyroxine at 3 years of age and beyond had permanent CHT and 17% had transient hypothyroidism. 5% (n=5) patients had normal thyroid function, 1% (n=1) possible transient hypothyroidism due to a variant in the TSH receptor and the remaining 1% (n=1) hyperthyrotormaninam which resolved. Only 27% (n=17) of patients underwent thyroid imaging of which 71% revealed a radiologically normal thyroid gland. Abnormalities were identified in 29% of which three patients had thyroid agenesis and one demonstrated thyroid dyshormonogenesis. Of those with a TSH 6–9.9 mU/l (n=16) 62% did not have permanent CHT compared to 21% (n=15) of those with a TSH >20 mU/l

Conclusion: The estimated incidence of CHT in the North East and Cumbria is one in 3000. This is in keeping with the national incidence as estimated by the newborn screening programme. 9% of infants with permanent CHT screened in the North East and Cumbria region would not have been identified if the recommended national cut off (10 mU/l) had been used. Although only a minority of babies underwent imaging, no baby in the 6–10 mU/l category had demonstrable dysgenesis or dyshormonogenesis. It remains to be determined whether these babies have benefited from thyroxine intervention.