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.