Beta HCG – pregnancy related, Plasma

Diagnostic Use

Human chorionic gonadotrophin (hCG) is a glycoprotein hormone produced by placental trophoblast cells. hCG is detectable in plasma approximately 10 days after conception and increases markedly over the first trimester of pregnancy, peaking at approximately 8-10 weeks before decreasing to lower (but still measurable) concentrations throughout the remainder of the pregnancy.

Indications for testing
- Confirming the presence/absence of a pregnancy
- Monitoring a threatened pregnancy
- Investigation of gestational trophoblastic disease and germ cell tumours (see hCG - tumour marker for more info).

Department

Core Biochemistry

Delphic Registration Code

HCGA

Synonyms

BHCG - pregnancy test
HCG - pregnancy test
Human chorionic gonadotrophin - pregnancy related
Pregnancy related HCG
Pregnancy test

Turnaround Time

3 hours

Test Code

3552

Specimen Type

• Serum
• Plasma

Specimen Requirements

Tube/Container Type:

Preferred

• Lithium Heparin - Non-gel (Green Cap)

Acceptable

• Serum (Red Cap)
• SST II (Gold Cap)
• Lithium Heparin - Gel (Green Cap)

Preferred Sample Volume (ml)

4.5

No of Samples Required

1

Aliquot Instructions

Sample Type

• Serum
• Plasma

Minimum Volume (ml)

0.5

Transport to Lab

Ambient (8 - 24 degrees Celsius)

Interpretation

hCG is detectable in plasma approximately 10 days after conception, therefore a detectable result is consistent with a current pregnancy. hCG concentrations vary greatly between individuals. This means that it is not possible to accurately determine the gestational age from the plasma hCG result. hCG concentrations are particularly high in multiple gestation pregnancies.

During the first trimester, hCG is expected to double on average every 48 hours. Monitoring serial hCG results may be useful in assessing the progress of a threatened pregnancy. Failure of hCG to increase as expected is suggestive of a failing or ectopic pregnancy.

Gestational trophoblastic disease (hydatidiform mole and choriocarcinoma) may be associated with very high hCG concentrations.

Perimenopausal and postmenopausal women often have mild elevations of hCG, thought to originate from the pituitary gland (pituitary hCG). This is a benign finding but can sometimes cause diagnostic confusion. Oral oestrogen would be expected to suppress pituitary hCG – this is sometimes used as a diagnostic test to rule out the possibility that the hCG is coming from a tumour.

Reference Intervals

<5 IU/L for non-pregnant adult

Test Method

Paramagnetic particle, chemiluminescent immunoassay performed on Beckman Coulter DxI 800 analysers, using Beckman Coulter Access reagents

Non-Funded Test Cost

$15.62 (Exclusive of GST)

Billing Code

3552

This test is not suitable for the primary diagnosis of malignancy. If the hCG level is not consistent with clinical status, results should be confirmed by an alternative method, which may include qualitative urine testing.

Contact Information

Enquiry Form