HCG blood test - quantitative
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:
- HCG urine test
- HCG blood test - qualitative
Serial beta HCG; Repeat quantitative beta HCG; Human chorionic gonadotropin blood test - quantitative; Beta-HCG blood test - quantitative; Pregnancy test - blood - quantitative
How the Test is Performed
A blood sample is needed. This is usually taken from a vein. The procedure is called a venipuncture.
How to Prepare for the Test
No special preparation is necessary.
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.
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.
HCG level rises rapidly during the first trimester of pregnancy and then slightly declines.
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:
- Fetal death
- Incomplete miscarriage
- Threatened spontaneous abortion (miscarriage)
- Ectopic pregnancy
There is very little risk in having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks of having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Blood accumulating under the skin (hematoma)
- Infection (a slight risk any time the skin is broken)
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Morrison LJ. General approach to the pregnant patient. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, PA: Elsevier Mosby; 2009:chap 175.
Webster RA. Reproductive function and pregnancy. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 25.
Reviewed By: Cynthia D. White, MD, Fellow American College of Obstetricians and Gynecologists, Group Health Cooperative, Bellevue, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.