Definition of Serum progesterone:

Serum progesterone is a test to measures the amount of progesterone in the blood. Progesterone is a hormone produced mainly in the ovaries.

In women, progesterone plays a vital role in pregnancy. After an egg is released by the ovaries (ovulation), progesterone helps make the uterus ready for implantation of a fertilized egg. It prepares the womb (uterus) for pregnancy and the breasts for milk production.

Men produce some amount of progesterone, but it probably has no normal function except to help produce other steroid hormones.

See also: Pregnanediol

How the test is performed:

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

How to prepare for the test:

Your health care provider may tell you to stop taking drugs that may affect the test. Drugs that can interfere with the test include progesterone and birth control pills.

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 done to diagnose or rule out disorders associated with abnormal progesterone levels, usually related to infertility or recurrent miscarriage. It may also be done to evalute bleeding in early pregnancy.