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.
HCG - urine HCG - serum - qualitative HCG - serum - quantitative
How the test is performed
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.
How to prepare for the test
How the test will feel
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.
Why the test is performed
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)
Review Date: 11/21/2010
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; and Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Redmond, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.