
Overview
The human chorionic gonadotropin (HCG) blood test measures the level of HCG hormone present in a sample of your blood.
What Facts?
Urine tests can be influenced by factors such as dehydration and the time of day that you test, while an HCG blood test can provide conclusive results even in cases where HCG levels are quite low. During pregnancy, cells in the developing placenta make HCG. The placenta is the sac that nourishes the egg after it’s fertilized and attaches to the uterine wall.


Relevance
HCG can first be detected in a blood sample about 11 days after conception. Levels of HCG continue to double every 48 to 72 hours. They reach their peak around 8 to 11 weeks after conception. HCG levels then decline and level off, remaining steady for the rest of the pregnancy.
What Causes?
The HCG blood test is performed to:
- confirm pregnancy
- determine the approximate age of the fetus
- diagnose an abnormal pregnancy, such as an ectopic pregnancy
- diagnose a potential miscarriage
- screen for Down syndrome
The BHCG blood test is sometimes used to screen for pregnancy before you undergo certain medical treatments that could potentially harm a developing baby.


How to Identify?
Beta HCG is considered a tumor markerTrusted Source, which means it’s a substance that’s excreted by some kinds of tumors. That’s why, in some cases, the HCG blood test may also be used to evaluate and manage certain types of cancer.
What Symptoms?
There may be a small amount of bruising where the needle was inserted. This can be minimized by applying pressure to the area for several minutes after the needle is removed.


What to Do?
When your lab test comes back, your doctor will tell you what your HCG levels are. These levels are measured in milli-international units of HCG hormone per milliliter of blood (mIU/mL).