Many women who are pregnant or trying to conceive have probably heard beta-hCG refer to pregnancy testing.
The test Beta-hCG (bhCG), measures the level of human chorionic Gonadotropin (hCG). This hormone can be produced within 10 days of conception and a higher level can confirm pregnancy.
This test can also be used for fertility evaluations (a synthetic version of the hormone is sometimes used in order to help follicles mature, trigger ovulation), and when there are concerns about a pregnancy.2
Also known as
Sometimes called the:
- Quantitative blood pregnancy test
- Quantitative hCG blood test
- Quantitative serial beta-hCG test
- Quantitative serum beta-HCG test
What Does Beta hCG Measure
Pregnancy testing is the measurement of hCG in the urine and blood.
A urine test can only determine if the sample contains hCG. The qualitative hCG blood test is the same.
The beta hCG test is quantitative and measures HCG levels in milli-international units per millilitre (mIU/ml). The HCG levels can be measured in milli-international units (mIU/ml).
Beta-hCG Tests are Used
A beta-hCG test can be used to confirm pregnancy during an early prenatal visit. This is to follow up to positive urine tests at home or in the office. The beta-hCG test is not necessary or always required in routine pregnancies. Transvaginal ultrasound is used by many practitioners at pregnancy confirmation visits to view visible evidence of pregnancy (the gestational sac).
If you are concerned about miscarriage or other pregnancy complications, the beta-hCG test can be used. Repeat tests are possible in these cases every two to three working days to assess how fast hCG levels rise.
The rate at which the hormone is rising in pregnancy is more important than its actual amount. Low levels of hCG that are slow to rise could indicate high miscarriage risk.5
Your doctor might order a beta hCG test to determine if fertility treatments are working. To ensure the best possible outcome, doctors who care for women who are taking hCG shots to increase their chances of conception or as part intrauterine insemination or in vitro fertilation (IVF), must carefully time a beta hCG test. This will ensure that the medication is not affecting test results.
There are also other uses for beta-hCG during pregnancy:3
- The age of a foetus can be determined by a beta-hCG test. However, it is not always possible to determine the exact gestational date. Your results, taken together with the date of your last period, can give your doctor an idea. However, the expected hCG ranges will change with each week in the first trimester.
- Fetal screening The beta hCG test is part of the maternal serum triple- and quadruple screening tests that are done between 15 to 20 weeks of gestation. It detects markers for certain fetal health issues, such as Down syndrome.4
The beta-hCG test is not related to pregnancy. It may be used to diagnose certain cancers.
Beta hCG Levels in Pregnancy
These are the most common hCG levels in pregnancy. These are only guidelines. Every pregnancy is unique.
Expected Levels of hCG in the First Trimester
Time Since Last PeriodhCG Range (if Pregnant)
3 Weeks 5 – 72 mIU/ml
4 Weeks 10 – 708 mIU/ml
5 Weeks 217-8,245 mIU/ml
6 Weeks, 152 to 32.177 mIU/ml
7 Weeks 4,059 – 153,767 MIU/ml
8 Weeks 31,366 to 149.094 mIU/ml
9 Weeks 59.109 to 135,901 MIU/ml
10 Weeks 44.186 to 170.409 mIU/ml
12 Weeks 27,107 – 201,165 mIU/ml
14 Weeks 24,302 – 93,646 MIU/ml
16 Weeks 8,904 – 55,332 mIU/ml
It doesn’t matter if you have high levels or lows of the hormone. There are many factors that can affect total hCG levels. These include maternal smoking, body weight index (BMI), ethnicity and parity (number of births a woman has had), as well as hyperemesis gravidarum (“severe morning sickness”).
Instead, doctors look for hCG levels that double in 48-72 hours from the initial level. This is something doctors look out for in the first weeks of pregnancy. It’s common for hCG levels peak at 8 to 11 weeks gestation and then to decrease over time.
What are hCG Doubling Times and
If Beta-hCG Levels Are Lower Than Expected
A second test will be done if your levels of hCG are low. This will confirm whether levels are rising or falling. Your beta-hCG levels may be lower than you expected, or they remain low after repeated testing.
- Miscalculated gestational age
- Possible miscarriage
- Ectopic pregnancy is when a fertilized egg implanted outside the uterus.
Your practitioner may recommend additional tests to confirm your pregnancy.
What does low hCG levels mean?
If Beta-hCG Levels Are Higher Than Expected
Possible reasons your beta-hCG levels might be higher than you expected.3
- A multiple pregnancies
- Incorrect pregnancy date
- Molar pregnancy: When a mass of tissue grows within the uterus and not a placenta
Atypical results will again be followed up by repeat testing and other evaluations in order to determine the cause.
What does high hCG levels mean?
A Word From Verywell
Do not jump to conclusions if you do not have the chance to discuss your lab results. Although informative, the beta-hCG test does not provide any information. It is only one of many ways doctors can gather information about a pregnancy and determine its status.