return to numerical index

return to index page


Test Directory -  17a - Hydroxyprogesterone

Clinical Indications

Diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. Levels may be measured following stimulation with ACTH (Synacthen) in investigation of late onset (or mild) CAH. May also be useful in monitoring response to corticosteroid therapy in CAH due to 21-hydroxylase deficiency.

Request Form

Combined Pathology Blood form (Yellow/Black)


Referral test: Analysed by Biochemistry, Royal London Hospital.

Specific Criteria

Investigation or monitoring of CAH

Patient Preparation and Collection 


Take blood before emergency administration of corticosteroids and preferably early morning. Samples should not be taken in newborn infants until at least 72 hours after birth and ideally after 92 hours.
In monitoring response to treatment, take blood between 08.00h and 09.00h before initiation of treatment for day and again 2 hours after first dose of corticosteroid.
Blood should be taken basal and at 30 minutes and 60 minutes following  Synacthen.

Turnaround Time

2 weeks


Yellow top (SST) tube or

Paediatric orange top (lithium-heparin)


2 ml


Yellow top (SST) tube or Paediatric Orange top (Heparin)

Causes for Rejection

Sample from newborn less than 48 hours after birth, insufficient clinical details.

Reference Range

Up to 10 days: Less than 20.0 nmol/L
6 months to 10 years: Less than 15.0 nmol/L
Over 10 years and Adults: 1.0 - 8.7


Peak levels following Synacthen: Less than 35 nmol/L excludes CAH, whilst a level greater than 60 nmol/L is consistent with CAH. Levels between 35 and 60 are borderline.

Lab. Handling

Processing: Aliquot (MPA) and store at 4C in separating fridge (CB39), referral rack.
:  17OHP and send or BPRO and track at -20C in separating freezer (CB40).

 Version 1.0 / July 2014                                                                                                           Approved by: Consultant Biochemist