A pregnancy test measures a hormone called human chorionic gonadotropin (HCG). HCG is a hormone produced during pregnancy. It appears in the blood and urine of pregnant women as early as 10 days after conception.

See also:

• HCG - urine
• HCG - serum - qualitative
• HCG - serum - quantitative

A pregnancy test may be performed using blood or urine. There are two types of blood pregnancy tests:

• Qualitative, which measures whether the HCG hormone is present
• Quantitative, which measures how much HCG is present

The blood test is done by drawing a single tube of blood and sending it to a laboratory. You may wait anywhere from a few hours to more than a day to get the results.

The urine HCG test is usually performed by placing a drop of urine on a prepared chemical strip. It generally takes 1 to 2 minutes for a result.

The urine test involves normal urination into a cup. The serum tests involve drawing blood through a needle and into a tube. Any discomfort you might feel from the blood draw will only last a few seconds.

This test may be done to:

• Determine if you are pregnant
• Diagnose abnormal conditions that can raise HCG levels
• Watch the development of the pregnancy during the first 3 months (quantitative test only)

HCG levels rise rapidly during the first trimester of pregnancy and then slightly decline.

HCG levels should double every 48 hours in the beginning of a pregnancy. HCG levels that do not rise appropriately may indicate a problem with your pregnancy. Some problems associated with an abnormally rising HCG level include miscarriage and ectopic (tubal) pregnancy.

Extremely high levels of HCG may suggest a molar pregnancy or more than one fetus -- for example, twins.

Your health care provider will understand the significance of your HCG levels, and he or she should discuss the levels with you.