This is a blood test to detect beta-HCG (human chorionic gonadotropin), a hormone normally produced during pregnancy.

Blood is drawn from a vein, usually on the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band cuff is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to swell with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

No special preparation is usually necessary.

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Most often, this test is performed to determine if you are pregnant or not. The serum HCG level may also be high in women with certain types of ovarian tumors or men with testicular tumors.

• The test is negative if you are not pregnant.
• The test is positive if you are pregnant.

If your serum HCG is positive and you do NOT have a pregnancy properly implanted in the uterus, it may indicate:

• ectopic pregnancy
• miscarriage
• testicular cancer
• trophoblastic tumor
• hydatidiform mole
• ovarian cancer

Possible risks from any blood test include:

• excessive bleeding
• fainting or feeling lightheaded
• hematoma (blood accumulating under the skin)
• infection (a slight risk any time the skin is broken)
• multiple punctures to locate veins

False positive tests may occur when certain hormones are increased, such as after menopause or when taking hormone supplements.

A pregnancy test is considered to be about 98% accurate. When the test is negative but pregnancy is still suspected, the test should be repeated in 1 week.

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.