Progesterone - serum
This is a test that measures the amount of progesterone in the blood.
How the test is performed
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 is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to fill 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.
For an infant or young child:
The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.
How to prepare for the test
Your health care provider may advise you to stop taking drugs that may affect the test. Drugs that can interfere with the test include progesterone and Birth control pills.
For infants and children:
The preparation you can provide for this test depends on your child’s age, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics:
- Infant test or procedure preparation (birth to 1 year)
- Toddler test or procedure preparation (1 to 3 years)
- Preschooler test or procedure preparation (3 to 6 years)
- School age test or procedure preparation (6 to 12 years)
- Adolescent test or procedure preparation (12 to 18 years)
How the test will feel
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.
Why the test is performed
This test is performed to evaluate disorders associated with abnormal progesterone levels. Progesterone is a steroid hormone that is made in, and released from, the corpus luteum, placenta, and adrenal gland.
In men, progesterone probably has no normal function except as an intermediate in the synthesis of other steroid hormones. In women, progesterone prepares the uterus for pregnancy and the breasts for milk production. After ovulation, progesterone blocks proliferation of the endometrium and stimulates the uterus to prepare for implantation of a fertilized egg. Progesterone levels continue to rise in early pregnancy.
Blood progesterone levels start to rise with the LH surge, midway through the menstrual cycle, continue to rise for about 6 to 10 days, and then fall in the absence of fertilization.
Urinary pregnanediol levels are an indirect measure of progesterone production. Progesterone is converted to pregnanediol by the liver before being secreted in the urine.
- female (preovulation): less than 1 ng/mL
- female (midcycle): 5 to 20 ng/mL
- male: less than 1 ng/mL
Note: ng/mL = nanograms per milliliter
What abnormal results mean
Greater-than-normal levels may indicate:
- adrenal cancer
- Ovarian cancer
Lower-than-normal levels may indicate:
- fetal death
- threatened abortion
- toxemia of pregnancy
Additional conditions under which the test may be performed:
- Ectopic pregnancy
What the risks are
- 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
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.
by David A. Scott, M.D.