Update of reference ranges for thyroid function tests
Printer-friendly versionFrom 1st September 2014, the Clinical Biochemistry department at Peterborough City Hospital will implement new reference ranges for thyroid function tests, namely TSH(thyroid stimulating hormone), FT4 (free thyroxine) and FT3 (free tri-iodothyronine).
The changes are as follows:
Thyroid stimulating hormone (TSH):
|
Age/sex |
Current reference range |
Updated reference range |
|
<12 months |
1.36-8.80 |
0.7-11.0 |
|
1 – 6 years old |
0.85-6.50 |
0.7-6.0 |
|
>6 years old |
0.3-4.2 |
0.3-4.2 |
|
Pregnant 1st Trimester |
||
|
Pregnant 2nd Trimester |
||
|
Pregnant 3rd Trimester |
0.2-3.2 |
Free thyroxine (FT4)
|
Age/sex |
Current reference range |
Updated reference range |
|
All Ages |
12-22 |
12-22 |
|
Pregnant 1st Trimester |
||
|
Pregnant 2nd Trimester |
9.6-17.0 |
|
|
Pregnant 3rd Trimester |
8.4-15.6 |
Free tri-iodothyronine (FT3)
|
Age/sex |
Current reference range |
Updated reference range |
|
<12 months |
3.1-6.8 |
3.0-9.3 |
|
1 – 20 years old |
3.9-8.0 |
|
|
>20 years old |
3.1-6.8 |
|
|
Pregnant 1st Trimester |
||
|
Pregnant 2nd Trimester |
||
|
Pregnant 3rd Trimester |
3.1-5.0 |
The changes are derived from data obtained from the departments supplier of the thyroid function test methods (Roche Diagnostics Ltd) and provide ranges tailored to patient age groups, and also trimester specific reference ranges in pregnancy (as recommended in the ‘UK Guidelines for the use of Thyroid Function tests’ published by the Association for Clinical Biochemistry and the British Thyroid Association).
If you have any queries regarding these changes, or thyroid function tests, please contact the laboratory via email: peh-tr.chemimm@nhs.net
