A quantitative human chorionic gonadotropin (HCG) test measures the specific level of HCG in the blood. HCG is a hormone produced in the body during pregnancy.
Other HCG tests include:
How the Test is Performed
A blood sample is needed. This is most often taken from a vein. The procedure is called a venipuncture.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
How to Prepare for the Test
No special preparation is needed.
HCG level rises rapidly during the first trimester of pregnancy and then slightly declines.
Risks of having blood drawn are slight, but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
- Blood accumulating under the skin (hematoma)
- Infection (a slight risk any time the skin is broken)
What Abnormal Results Mean
Higher than normal level may indicate:
- Normal pregnancy
- More than one fetus, for example, twins or triplets
- Choriocarcinoma of the uterus
- Hydatidiform mole of the uterus
- Ovarian cancer
- Testicular cancer (in men)
Lower than normal levels may indicate:
Why the Test is Performed
HCG appears in the blood and urine of pregnant women as early as 10 days after conception. Quantitative HCG measurement helps determine the exact age of the fetus. It can also diagnose abnormal pregnancies, such as ectopic pregnancies, molar pregnancies, and possible miscarriages. It is also used as part of a screening test for Down syndrome.
This test is also done to diagnose abnormal conditions not related to pregnancy that can raise HCG level.
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Jeelani R, Bluth MH. Reproductive function and pregnancy. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. St Louis, MO: Elsevier; 2017:chap 25.