Pregnancy test
Also known as: hCG test, beta-hCG, urine pregnancy test
Detects human chorionic gonadotropin, a hormone made by the placenta from about a week after implantation. Urine tests give a yes/no answer; a blood test gives a number that should double every two days in a healthy early pregnancy.
- Kind
- Laboratory test
- Categories
- Pregnancy & prenatal, Point-of-care & home testing
- Specimen
- Urine (spot sample), Serum
- Method
- Immunoassay, Point-of-care device
What it measures
| Measure | What it tells you |
|---|---|
| Urine hCG | Positive from around the first missed period; modern tests detect 20-25 IU/L. |
| Serum hCG | Quantitative; used to track ectopic pregnancy, miscarriage and molar pregnancy, and some tumours. |
Why it is ordered
- A missed period, nausea, breast tenderness
- Abdominal pain or bleeding in any woman of reproductive age (to exclude ectopic pregnancy)
- Before X-rays, CT, surgery and many drugs
- Monitoring after ectopic pregnancy or molar pregnancy treatment
How it is done
A drop of urine on a test strip, ideally first-morning; or a venous blood sample.
Preparation. None; testing before the missed period risks a false negative.
Reading the result
| Finding | Usual meaning |
|---|---|
| Positive urine test | Pregnant, almost always; an ultrasound from 6 weeks locates the pregnancy |
| Positive test with pain or bleeding | Ectopic pregnancy must be excluded urgently |
| Serum hCG rising slowly | Failing or ectopic pregnancy |
Reference ranges vary by laboratory, method, age, sex and clinical context; a result is read against the person, not a table.
Limitations
False negatives when tested too early or with very dilute urine; rare false positives from fertility drugs, some tumours and recent pregnancy loss.
Catalogued concepts this page covers
Concepts of the master test taxonomy that resolve to this page; each links to its category.