hCG Blood Test

• hCG (measured): a quantitative serum hCG result.

This test does not include an ultrasound scan, progesterone, or the related tumour markers AFP and LDH. It is a single measurement and does not track change over time.

hCG is a glycoprotein hormone made by trophoblast cells, which go on to form the placenta. Production begins about six days after fertilisation. Its first job is to keep the corpus luteum in the ovary producing progesterone, which maintains the womb lining until the placenta can take over.

hCG is built from two parts. Its alpha subunit is shared with LH, FSH and TSH, while the beta subunit is specific to hCG, which is why laboratory tests target the beta part. In early pregnancy, blood hCG roughly doubles every two to three days, peaks around ten weeks after the last period, then falls to a lower level for the rest of pregnancy. It becomes undetectable within a few weeks of birth.

Blood tests are more sensitive than urine tests and can detect pregnancy earlier. They also give a number rather than a yes or no, which is why hospitals use them to follow early pregnancy problems.

Outside pregnancy, hCG is used by specialists as a tumour marker for gestational trophoblastic disease (including molar pregnancy and choriocarcinoma) and for some testicular and ovarian germ cell tumours, where it helps with diagnosis, staging and monitoring. In these settings it is always interpreted with scans and other markers by the specialist team.

Outside pregnancy, hCG is normally undetectable or very low. Your report will show the laboratory's threshold for a negative result. In pregnancy, levels vary so widely between individuals at the same stage that a single number cannot date a pregnancy precisely, show where it is located, or tell whether it will continue.

In NHS early pregnancy services, NICE guidance (NG126) uses two hCG measurements taken about 48 hours apart, alongside a transvaginal ultrasound. A rise of more than 63% makes a developing pregnancy in the womb likely but does not rule out an ectopic pregnancy, and a fall of more than 50% suggests the pregnancy is unlikely to continue. These patterns are interpreted by clinicians with a scan and are not something a single private test can provide.

Why hCG can be detected without a current pregnancy

• A recent pregnancy, miscarriage or termination: hCG takes time to clear, and urine tests can stay positive for several weeks
• Medicines containing hCG, such as some fertility treatments
• Around and after the menopause, the pituitary gland can release small amounts of hCG
• Interfering antibodies in some people's blood can cause a false-positive result on certain methods
• Rarely, hCG-producing tumours

Why a result can be negative in early pregnancy

Testing very soon after conception may give a negative result before hCG has risen. If your period is still missed, repeat the test or see your GP.

An unexpected positive result when pregnancy is unlikely should be discussed with your GP so that it can be checked with a different method. With your consent we can write to your GP with your results.

Most pregnancies are confirmed with a home urine test, and NHS antenatal care begins with your GP or midwife. A blood hCG test can be helpful when a home result is unclear, or when you want a laboratory-measured result for your own records before a booked appointment.

For some situations the NHS provides specialist pathways that this test cannot replace. After a molar pregnancy, all women in the UK are registered with a national hCG follow-up programme run from Charing Cross Hospital in London, Weston Park Hospital in Sheffield and Ninewells Hospital in Dundee. Fertility clinics time their own hCG tests after treatment. Men who notice a lump or swelling in a testicle should see their GP promptly; hCG is not a screening test for testicular cancer, and normal tumour markers do not exclude it.

May be useful if you

• have no pain or bleeding and want a laboratory-measured hCG result
• have had an unclear home pregnancy test and want clarification before seeing your GP or midwife

Not suitable if you

• have pain, bleeding, shoulder tip pain, dizziness or fainting and might be pregnant: seek urgent NHS care instead
• are already under the care of an early pregnancy unit: follow their testing plan
• need follow-up after a molar pregnancy: this is provided by the national screening service
• are having fertility treatment: your clinic will arrange and time your hCG test
• want to screen for cancer: hCG is not a screening test

• Established use: confirming and following pregnancy, and monitoring specific tumours under specialist care.
• Relevant to midlife: around and after the menopause, the pituitary can produce small amounts of hCG, so a low positive result in this age group does not necessarily mean pregnancy or disease and should be reviewed by a GP.
• Unproven: hCG has no established role as a marker of healthy ageing, wellbeing or longevity.

• Timing: a blood test can detect pregnancy earlier than a urine test, but testing too early can still give a negative result. Testing from the day your period is due gives a more reliable answer.
• Medicines: tell us if you have had any fertility treatment or injection containing hCG, and the date of your last dose.
• Recent pregnancy: tell us if you have been pregnant in the last few months, including miscarriage or termination.
• Biotin: mention any biotin or hair, skin and nail supplement when booking, as high doses can affect some laboratory tests.
• Symptoms: if pain or bleeding starts before your appointment, do not wait for the test. Seek urgent NHS care.

Choose how your sample is taken when you book. We confirm the collection option, any collection fee and the expected turnaround time before you book.

• Juvenology Clinic, Maidstone (82 King Street, Maidstone ME14 1BH): Available.
• Partner clinic near you, anywhere in the UK: Available on request. We confirm availability for your postcode before you book.
• Postal home finger-prick kit: Ask before ordering. We offer a home kit only where the laboratory confirms this test is suitable for a finger-prick sample.

Sample: Venous blood sample (serum)

Collection notes: For non-urgent use only. Postal delays make a home kit unsuitable whenever the timing of the result matters. Anyone who might be pregnant and has pain, bleeding, shoulder tip pain, dizziness or fainting should seek urgent NHS care rather than book this test.

The price of this test covers laboratory analysis and the laboratory's results report. The report lists each result beside the laboratory's reference range.

Beyond the blood test: optional support, priced separately

• Personalised written interpretation report: £50
• General consultation: £50
• Results consultation (results discussion and follow-up advice): £100
• Personalised programme: from £150, after we assess whether a programme suits you

Consultations are with Marina, an NMC-registered nurse. She explains what your results show and how they relate to lifestyle. No prescription service is offered with these tests.

If a result suggests you need medical follow-up, we will recommend that you see your GP and, with your consent, can provide a letter to take with you. A blood test cannot rule out every condition. If you have symptoms, speak to your GP or NHS 111, and call 999 in an emergency.

How soon can a blood test detect pregnancy?

Blood tests are more sensitive than urine tests and can detect pregnancy earlier, but a very early test can still be negative. If your period remains late, repeat the test or speak to your GP.

Can this test tell me whether my pregnancy is in the right place?

No. Only an ultrasound scan, often with hCG measurements 48 hours apart in an early pregnancy service, can assess this. If you have pain or bleeding, seek urgent NHS care.

My home test showed a faint line. Will this help?

A quantitative blood result can clarify whether hCG is present. If you have any pain or bleeding, contact NHS 111 or your GP rather than waiting for the result.

I recently had a miscarriage. Should I use this test?

Please follow the plan given by your hospital or GP, which usually includes a urine pregnancy test after about three weeks. Return to them if it is still positive.

Can hCG be positive if I am not pregnant?

Yes, occasionally, for example after a recent pregnancy, after hCG-containing fertility treatment, around the menopause or because of assay interference. Your GP can arrange confirmation with a different method.

Is interpretation of my result included?

The price covers laboratory analysis and the laboratory's report. You can add a personalised written interpretation report (£50) or a results consultation (£100).

1. Ectopic pregnancy and miscarriage: diagnosis and initial management (NG126). National Institute for Health and Care Excellence. https://www.nice.org.uk/guidance/ng126/chapter/Recommendations
2. Ectopic pregnancy: symptoms. NHS. https://www.nhs.uk/conditions/ectopic-pregnancy/symptoms/
3. Human chorionic gonadotrophin (hCG) test. Lab Tests Online UK. https://labtestsonline.org.uk/tests/human-chorionic-gonadotrophin-hcg-test
4. Chen J, et al. Persistent mild increase of human chorionic gonadotropin levels in a 31-year-old woman after spontaneous abortion. Canadian Medical Association Journal, 2016;188(17–18):E504–E508. https://doi.org/10.1503/cmaj.151481
5. Information about molar pregnancy. Imperial College Healthcare NHS Trust, Charing Cross Hospital Gestational Trophoblastic Disease Service. https://imperial.nhs.uk/our-services/cancer-services/gestational-trophoblastic-disease/information-about-molar-pregnancy
6. Testicular cancer: guide for trainees. British Association of Urological Surgeons. https://www.baus.org.uk/trainees/testicular_cancer.aspx