Pathology Handbook

HCG (?ectopic)


Human Chorionic Gonadotrophin (HCG)

Clinical Indications

Ectopic pregnancy should be considered and serum hCG measured in any young woman with unexplained abdominal pain whether or not she has missed a period or had abnormal vaginal bleeding.

Results should not be interpreted in isolation but in the context of clinical features

Serum hCG can be positive within 7-10 days of conception.

If an ectopic pregnancy or a miscarriage is suspected, two specimens should be taken 48 hours apart.  For an intrauterine pregnancy, the hCG should double during this period.  Generally the rate of increase is slower for ectopic pregnancies, although for early ectopic pregnancies the hCG can still double in 48 hours.

For a complete miscarriage, the hCG should halve during this period.
If the serum hCG is over 5,000 U/L, it should be possible to confirm intrauterine pregnancy by transvaginal (not abdominal) ultrasound scan.

Request Form 

Request on ICE


On request if specific criteria met.

Specific Criteria

Suspected ectopic pregnancy.

Turnaround Time

Same Day




1 ml


Vacutainer gold top

Causes for Rejection

Unlabelled or incorrectly labelled sample

Reference Range

Non-pregnancy levels < 5 U/mL.


Levels may remain raised for up to 2 weeks following childbirth and up to 4 weeks following abortion.

Patients receiving courses of hCG (e.g. Pregnyl) or hMG (Perganol) may give false positive results for a few days after administration of the drug.