Beta-hCG
The pregnancy hormone — the basis of pregnancy tests. In early pregnancy it rises steeply and predictably, which is used to date a pregnancy and to monitor concerns like ectopic pregnancy or miscarriage. It is also a tumour marker for certain cancers.
What it measures
Human chorionic gonadotropin (hCG), measured as its beta subunit, is the hormone produced by the placenta from very early in pregnancy. Its detection in urine or blood is the basis of pregnancy testing. The blood test is quantitative — it gives an actual number — which makes it valuable beyond simply confirming pregnancy: in early pregnancy the level rises steeply and predictably (roughly doubling every couple of days), so serial measurements help date a pregnancy and, importantly, assess concerns such as a possible ectopic (tubal) pregnancy or miscarriage, where the rise is slower or the level falls. Very high levels occur with multiple pregnancies and with molar pregnancy. Beyond pregnancy, hCG is a tumour marker: it is produced by certain germ-cell tumours (of the testis or ovary) and trophoblastic tumours, so it is used, alongside AFP, to diagnose and monitor these. A low or negative result simply means no pregnancy and no hCG-producing process.
What a high value can mean
- Pregnancy — the usual reason; the level reflects how advanced the pregnancy is.
- Multiple pregnancy (twins or more) — higher than expected.
- Molar pregnancy or trophoblastic disease — very high levels.
- Germ-cell tumours (testis or ovary) — an hCG-producing cancer; used as a tumour marker with AFP.
- A slower-than-expected rise in early pregnancy — can signal an ectopic pregnancy or a failing pregnancy.
What a low value can mean
- Not pregnant — the expected result outside pregnancy.
- A falling level in early pregnancy — can indicate a miscarriage or a resolving pregnancy.
- After treatment of an hCG-producing tumour — a fall toward normal indicates response.
When to discuss with a doctor
A positive pregnancy test is confirmed and, where needed, quantified with a blood beta-hCG. The quantitative test is most useful when there is a concern in early pregnancy: pain or bleeding raising the possibility of an ectopic pregnancy or miscarriage, where the pattern of the level over 48 hours (rising appropriately, plateauing or falling) guides urgent care alongside an ultrasound. Severe abdominal pain, shoulder-tip pain or faintness in early pregnancy is an emergency (possible ectopic). As a tumour marker, hCG is used with AFP in the assessment and monitoring of germ-cell tumours. Mediora.AI shows beta-hCG alongside the relevant markers; the interpretation, especially in early-pregnancy concerns, belongs with your doctor.