17-hydroxyprogesterone

5 mL blood in plain tube. Some laboratories may offer an assay on dried blood spot on filter paper.

Immunoassay, LC-MS/MS

Depends on age and phase of cycle (higher in luteal phase) - consult pathologist.

Diagnosis, monitoring and management of congenital adrenal hyperplasia.

Increased in some rare adrenal tumours.

Included in neonatal screening programs.

In mildly affected patients, measurement after adrenal stimulation with Synacthen may be required to confirm the diagnosis.

An increased level indicates 21-hydroxylase deficiency.

In patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency, monitoring treatment may require levels at various times of the day. Levels should not be markedly elevated and should not be suppressed immediately prior to the next dose of glucocorticoid.