Sample type: Blood spot

Test name: TSH

Condition / Indication: Monitoring children and adults with Down syndrome or needle-phobia, to screen for primary hypothyroidism or detect under replacement with thyroxine.

Special precautions & notes: Please collect two bloodspots, each at least 8mm in diameter.

Reference range: <2.2 mU/L. Please note that bloodspot levels are lower than the equivalent plasma/serum TSH level due to the dilution effect of red blood cells. Bloodspot TSH results falling outside the reference range should be confirmed by a venous thyroid function profile to confirm diagnosis and/or guide management.

Container: Bloodspots on a newborn screening card

Ideal volume (mL): 2x Spots

Referred outside NBT for analysis? No

Discipline: Clinical Biochemistry

Section: Newborn Screening

Turnaround time: 7 days

Information for Laboratories referring samples for analysis at NBT:

Mark the card with 'Bloodspot TSH' clearly, include a request form with details of where the report should be sent. Store at room temperature in glassine envelope. Send by 1st class post or hospital transport.

Method:

Immunoassay