The best way to confirm a pregnancy is by completing a hCG blood test. This test is often also called a beta-hCG test, with beta referring to the beta protein found on the hCG hormone. The hCG hormone is produced during pregnancy, and the blood test measures the amount of hormone circulating in the blood. A result is considered to be positive when hCG levels are greater than 5.0 mlU/ml.
This pregnancy-related blood test will be more accurate and reliable if completed after a period is late. Testing completed before a late period may yield a false negative result.
Fasting before this test is not required, and results are usually reported within a few hours after the blood draw.
If you have completed the hCG blood test already, enter your result below to determine how far along you are in your pregnancy:
What is hCG?
hCG stands for human chorionic gonadotrophin, which is a hormone typically produced when a woman is pregnant. In some cases, hCG can also be produced as a result of certain diseases that cause severe hormonal changes. The beta hCG blood test is usually ordered when pregnancy is suspected, however, as pregnancy is more easily confirmed with the presence of this hormone in the blood. hCG can also be detected in urine, which is how over-the-counter pregnancy tests work.
When a hCG test result is undetectable or inconclusive and the woman has symptoms of pregnancy, the test should be repeated 3 days later.
Quantitative hCG table
The following table shows the average amount of hCG hormone present in each week of pregnancy:
|Gestational age||Amount of hCG detected in the blood|
|You are not pregnant - Negative result||Less than 5 mlU/ml|
|3 weeks pregnant||5 to 50 mlU/ml|
|4 weeks pregnant||5 to 426 mlU/ml|
|5 weeks pregnant||18 to 7.340 mlU/ml|
|6 weeks pregnant||1.080 to 56.500 mlU/ml|
|7 to 8 weeks pregnant|
7.650 to 229.000 mlU/ml
|9 to 12 weeks pregnant||25.700 to 288.000 mlU/ml|
|13 to 16 weeks pregnant||13.300 to 254.000 mlU/ml|
|17 to 24 weeks pregnant||4.060 to 165.500 mlU/ml|
|25 to 40 weeks pregnant||3.640 a 117.000 mlU/ml|
This blood test should be completed only after your period is late. If completed before a late period, you may get a false negative results (which means that you may be pregnant, but the hCG is still too low to be detectable).
Difference between quantitative and qualitative hCG
As the name implies, the quantitative hCG test indicates the exact amount or level of hormone present in the blood. An hCG blood test is an example of quantitative hCG - the blood sample is analyzed in the laboratory and the amount of hormone present is measured. Depending on the amount of hormone, it is possible to estimate how far along you are in the pregnancy.
The over-the-counter urine pregnancy test is an example of a qualitative hCG test. This type of test only confirms whether the hormone is present in the urine or not, and does not give you an exact amount like the blood test. Usually your doctor will order a quantitative hCG test (or a blood test) to confirm pregnancy after a qualitative hCG test.
How to know if you are pregnant with twins
With twin pregnancies, the hormone levels will generally be higher than the averages indicated in the table above. However, a twin pregnancy is most accurately confirmed through an ultrasound completed after 6 weeks.
A twin pregnancy may be suspected if you know approximately how far along you are in your pregnancy (based on your last menstrual period) and your beta hCG levels do not correspond with the averages listed above.
Other exam results
Presence of hCG in the blood may also indicate problems such as ectopic pregnancy, miscarriage or anembryonic pregnancy (also known as a blighted ovum, which is when the embryo doesn’t develop).
These conditions are usually suspected when the hormone levels are lower than expected for the gestational age. Follow-up with your doctor is advised to assess the cause of this type of hormonal change.
What to do after you confirm pregnancy
After confirming pregnancy with the blood test, you should plan to participate in prenatal care with your family doctor and obstetrician. Your pregnancy should be monitored to ensure your health and and the health of the baby, and so that you can avoid complications such as pre-eclampsia or gestational diabetes. Learn more about the common symptoms that may appear in early pregnancy.