Preferred Sample Type
Suitable Specimen Types
- Serum
- EDTA Plasma
- Li Hep Plasma
Sample Processing in Laboratory
Usual
Sample Preparation
Centrifuge
Turnaround Time
1 daySample Stability
Store at 4'C for up to 7 days. Store separated serum/plasma frozen if analysis is to be delayed.
Thyrotrophin (TSH)
General Information
The synthesis and secretion of TSH is stimulated by Thyrotrophin Releasing Hormone (TRH) in response to low levels of circulating thyroid hormones. TSH is formed in specific basophil cells of the anterior pituitary gland and is subject to a circadian secretion sequence. TSH has a stimulating action in all stages of thyroid hormone formation and secretion from the Thyroid gland. Determination of TSH serves as an initial test of thyroid function as levels will change in response to small changes in the concentrations of circulating free thyroid hormone levels.
Patient Preparation
None
Notes
TSH is performed as the first line Thyroid Function Test. FT4 analysis may be reflexed depending on the TSH result.
Trimester-specific reference ranges for thyroid function:
|
Abbott reference range |
Trimester 1 |
Trimester 2 |
Trimester 3 |
|
|
TSH (mIU/L) |
0.4 - 4.9 |
0.0878-2.8293 |
0.1998-2.7915 |
0.3070-2.9028 |
|
FT4 (pmol/L) |
9 - 19 |
10.53-18.28 |
9.53-15.68 |
8.63-13.61 |
|
FT3 (pmol/L) |
2.9 – 4.9 |
3.52-6.22 |
3.41-5.78 |
3.33-5.59 |
Reference Range
TSH - 0.4-4.9 mIU/L
(source: Abbott Diagnostics)
Specifications
- EQA Scheme?: Yes
-
EQA Status:
NEQAS