DefinitionA pregnancy test measures a hormone in the body called human chorionic gonadotropin (HCG or 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. How the Test is PerformedA pregnancy test is done using blood or urine. There are 2 types of blood tests:
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 most often performed by placing a drop of urine on a prepared chemical strip. It takes 1 to 2 minutes for a result. For the urine test, you urinate into a cup. For the blood test, the health care provider uses a needle and syringe to draw blood from your vein into a tube. Any discomfort you might feel from the blood draw will only last a few seconds. How the Test will FeelFor the urine test, you urinate into a cup. For the blood test, the provider uses a needle and syringe to draw blood from your vein into a tube. Any discomfort you might feel from the blood draw will only last a few seconds. Why the Test is PerformedThis test is done to:
Normal ResultsHCG level rises rapidly during the first trimester of pregnancy and then slightly declines. What Abnormal Results MeanHCG level should almost double every 48 hours in the beginning of a pregnancy. An HCG level that does not rise appropriately may indicate a problem with your pregnancy. Problems related to an abnormal rising HCG level include miscarriage and ectopic (tubal) pregnancy. An extremely high level of HCG may suggest a molar pregnancy or more than one fetus, for example, twins. Your provider will discuss the meaning of your HCG level with you. ConsiderationsUrine pregnancy tests will only be positive when you have enough HCG in your blood. Most over-the-counter home pregnancy tests will not show that you are pregnant until your expected menstrual cycle is late. Testing before this will often give an inaccurate result. The HCG level is higher if your urine is more concentrated. A good time to test is when you first get up in the morning. If you think you are pregnant, repeat the pregnancy test at home or at your provider's office. ReferencesJeelani R, Bluth MH. Reproductive function and pregnancy. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 26. Warner EA, Herold AH. Interpreting laboratory tests. In: Rakel RE, Rakel DP, eds. Textbook of Family Medicine. 9th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 14. | |
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Review Date: 11/10/2022 Reviewed By: John D. Jacobson, MD, Department of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. | |
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Pregnancy test
