A progesterone test measures the amount of the
hormone progesterone in a blood sample.
Progesterone is a female hormone produced by the
ovaries during release of a mature egg from an ovary
(ovulation). Progesterone helps prepare the lining of
the uterus (endometrium) to receive the egg if it becomes
fertilized by a sperm. If the egg is not fertilized, progesterone levels drop
and menstrual bleeding begins.
During pregnancy, the
placenta also produces high levels of progesterone,
starting near the end of the
first trimester and continuing until the baby is born.
Levels of progesterone in a pregnant woman are about 10 times higher than they
are in a woman who is not pregnant.
Some types of cancer cause
abnormal progesterone levels in men and women.
Why It Is Done
A progesterone test is done to:
- Help find the cause of
- Monitor the success of
medicines for infertility or the effect of treatment with
- Help determine whether ovulation is
- Assess the risk of
- Monitor the function of the
ovaries and placenta during pregnancy.
- Help diagnose problems with
adrenal glands and some types of cancer.
How To Prepare
You may be asked to stop taking
medicines (including birth control pills) that contain
estrogen or progesterone, or both, for up to 4 weeks
before having a progesterone test.
Tell your doctor if you have
had a test that used a radioactive substance (tracer) within the last 7 days.
Recent tests such as a thyroid scan or bone scan that used a radioactive tracer
can interfere with the test results.
Let your doctor know the
first day of your last menstrual period. If your bleeding pattern is light or
begins with spotting, the first day is the day of heaviest bleeding.
Talk to your doctor about any concerns you have regarding the need for
the test, its risks, how it will be done, or what the results will mean. To
help you understand the importance of this test, fill out the
medical test information form(What is a PDF document?).
How It Is Done
The health professional drawing blood
- Wrap an elastic band around your upper arm to
stop the flow of blood. This makes the veins below the band larger so it is
easier to put a needle into the vein.
- Clean the needle site with
- Put the needle into the vein. More than one needle stick
may be needed. Attach a tube to the needle to fill it with blood.
- Remove the band from your arm when enough blood is
- Apply a gauze pad or cotton ball over the needle site as
the needle is removed.
- Apply pressure to the site and then a
For a woman who is having problems with her menstrual cycle
or who cannot become pregnant, more than one blood sample for progesterone
testing may be needed to help identify the problem. A sample may be taken each
day for several days in a row.