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Key facts
- Human chorionic gonadotropin (hCG) is a hormone that’s found during pregnancy.
- It can be measured in your urine and blood.
- Your hCG levels are highest towards the end of your first trimester.
- Your hCG levels gradually go down over the rest of your pregnancy.
What is hCG levels?
Human chorionic gonadotropin (hCG) is a hormone that is found when you’re pregnant. It’s made by your placenta.
When you’re pregnant, hCG can be found in your urine (wee) and blood. Blood tests that measure your hCG levels can also be used to check how well your pregnancy is progressing.
Confirming your pregnancy
The detection of hCG is used to confirm your pregnancy. After you conceive (when the sperm fertilises the egg), your developing placenta begins to produce and release hCG.
It takes about 2 weeks for your hCG levels to be high enough to be found by a home pregnancy test.
A positive home test result is almost certainly correct, but a negative result is less reliable.
If you do a pregnancy test on the first day after your missed period, and it’s negative, wait about a week. If you still think you might be pregnant, do the test again or see your doctor.
hCG blood levels by week
If your doctor needs more information about your hCG levels, they may order a blood test.
If you’re pregnant, low levels of hCG may be found in your blood about 6 to 10 days after ovulation.
hCG levels are highest towards the end of your first trimester. They then gradually decline over the rest of your pregnancy.
| Length of pregnancy | Average hCG levels in blood during pregnancy |
|---|---|
| 4 weeks | 0 – 750 µ/L |
| 5 weeks | 200 – 7,000 µ/L |
| 6 weeks | 200 – 32,000 µ/L |
| 7 weeks | 3,000 – 160,000 µ/L |
| 8 – 12 weeks | 32,000 – 210,000 µ/L |
| 13 – 16 weeks | 9,000 – 210,000 µ/L |
| 16 – 29 weeks (second trimester) | 1,400 – 53,000 µ/L |
| 29 – 41 weeks (third trimester) | 940 – 60,000 µ/L |
Higher than expected hCG levels may happen if you’re are pregnant with twins and triplets. It may also happen if you have an abnormal growth in your uterus (womb).
Falling hCG levels may show a pregnancy loss (miscarriage).
Low levels of hCG or levels that are rising more slowly than expected may be due to an ectopic pregnancy. This is when your fertilised egg implants outside of the uterus, often in your fallopian tube. Or you may also be at risk of miscarriage.
Levels of hCG in your blood don’t provide a diagnosis of anything. They can only suggest that there are issues to look into.
hCG levels and multiple pregnancies
One of the ways of diagnosing a multiple pregnancy is by testing your hCG levels. A high level may indicate you are carrying multiple babies, but it can also be caused by other factors. You will need an ultrasound to confirm that you’re expecting more than one baby.
