At a Glance
Why Get Tested?
When to Get Tested?
At specific times during a woman's menstrual cycle to determine whether/when she is ovulating; during early pregnancy when symptoms suggest an ectopic or failing pregnancy; throughout pregnancy to help determine placenta and fetal health; and when a woman has abnormal uterine bleeding
A blood sample drawn from a vein in your arm; a limited number of laboratories can perform this test on saliva.
Test Preparation Needed?
The Test Sample
What is being tested?
This test measures the level of progesterone in the blood. Progesterone is a steroid hormone whose main role is to help prepare a woman's body for pregnancy; it works in conjunction with several other female hormones.
On a monthly basis, the hormone estrogen causes the lining of the uterus, the endometrium, to grow and replenish itself, while a surge in luteinizing hormone (LH) leads to the release of an egg from one of two ovaries. A corpus luteum then forms in the ovary at the site where the egg was released and begins to produce progesterone. This progesterone, supplemented by small amounts produced by the adrenal glands, stops endometrial growth and readies the uterus for the possible implantation of a fertilized egg.
If fertilization does not occur, the corpus luteum degenerates, progesterone levels drop, and menstrual bleeding begins. If a fertilized egg is implanted in the uterus, the corpus luteum continues to produce progesterone. After several weeks, the placenta replaces the corpus luteum as the main source of progesterone, creating relatively large amounts of the hormone throughout the rest of a normal pregnancy.
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm. A limited number of laboratories can perform this test on saliva.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed. The patient's last menstrual period and trimester of pregnancy should be noted.
Ask a Laboratory Scientist
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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
Sources Used in Current Review
Pagana, K. D. & Pagana, T. J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 763-764.
Clarke, W. and Dufour, D. R., Editors (© 2006). Contemporary Practice in Clinical Chemistry: AACC Press, Washington, DC. Pp 359-360.
Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 894-897.
Vorvick, L. and Storck, S. (Updated 2009 April 12). Serum progesterone. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003714.htm. Accessed November 2009.
(© 2003). American Society for Reproductive Medicine. Age and Fertility, A Guide for Patients [On-line information]. PDF available for download at http://www.asrm.org/Patients/patientbooklets/agefertility.pdf through http://www.asrm.org. Accessed November 2009.
Sources Used in Previous Reviews
Thomas, Clayton L., Editor (1997). Taber's Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].
Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.
Oriel, K. and Schrager, S. (1999 October 1). Abnormal Uterine Bleeding. American Family Physician [On-line journal]. Available online at http://www.aafp.org/afp/991001ap/1371.html through http://www.aafp.org.
Chen, P. Updated (2001 August 10, Updated). Serum progesterone. MEDLINEplus Health Information [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003714.htm.
Tenore, J. (2000 February 15). Ectopic Pregnancy. American Family Physician [On-line journal]. Available online at http://www.aafp.org/afp/20000215/1080.html through http://www.aafp.org.
NHLBI (2002). The Women's Health Initiative. New Facts About: Estrogen/Progestin Hormone Therapy. National Institutes of Health, National Heart, Lung and Blood Institute [On-line information]. Available online at http://www.nhlbi.nih.gov/whi/hrtupd/ep_facts.htm through http://www.nhlbi.nih.gov.
ARUP. Progesterone. ARUP's Guide to Clinical Laboratory Testing (CLT) [On-line information]. Available online at http://www.aruplab.com/guides/clt/tests/clt_148b.htm through http://www.aruplab.com.
Spengler, R. (2000 October 30, updated). Progesterone. WebMD [on-line information]. Available online at http://my.webmd.com/encyclopedia/article/1689.52570 through http://my.webmd.com.
NCI (2002 July 16). Questions and Answers: Use of Hormones After Menopause. National Cancer Institute, News from the NCI [On-line press release]. Available online at http://newscenter.cancer.gov/pressreleases/estrogenplus.html through http://newscenter.cancer.gov.
Merck. Hormones and Reproduction. The Merck Manual of Medical Information - Home Edition [On-line information]. Available online at http://www.merck.com/pubs/mmanual_home/sec22/232.htm through http://www.merck.com.