A progesterone blood test is done to determine how much of the progesterone hormone is in a sample of blood. This female hormone is produced when a mature egg is released from an ovary during a process known as ovulation. This hormone helps to prepare the endometrium (uterine lining) to accept the egg if sperm fertilizes it. If the egg goes without being fertilized, menstrual bleeding occurs and progesterone levels drop.
When a woman is pregnant, high levels of this female hormone are produced by the placenta, beginning around the end of her first trimester of pregnancy and going on until she gives birth to a baby. A pregnant woman’s progesterone levels are approximately ten times higher than it is in a woman who is not pregnant.
Why is the Progesterone Blood Test Done?
This blood test is performed for a variety of reasons. These include:
- Help with determining why a woman in infertile
- Help with determining whether or not ovulation is occurring
- To monitor placenta and ovary function during pregnancy
- To monitor how well infertility medications are working or how the treatment is affecting the patient
- To determine a woman’s risk of having a miscarriage
- To help in diagnosing certain types of cancer and adrenal gland problems
How to Prepare for this Blood Test
Certain things may have to be done to prepare for this test. Preparation is done to ensure that the results are as accurate as possible and to ensure patient safety. Preparation methods can include:
- Not taking birth control pills, or other medications, containing progesterone or estrogen, or both for as long as four weeks prior to this test.
- The patient should make their doctor aware of what the first day of their last menstrual cycle was.
- The patient should tell their doctor if they have had any medical testing in the last seven days that used tracer (radioactive substance), such as a bone scan or a thyroid scan.
How is this Blood Test Done?
The progesterone blood test is done by a healthcare professional. They will tie a tourniquet a few inches above the intended puncture site, palpate for a good vein, then clean the puncture site with an antiseptic. They will then insert the needle into the patient’s vein, push the tube into the other end of the needle, then allow the tube to fill with the right amount of blood. Once enough blood is collected, the tourniquet is removed, a small gauze square is placed on the puncture site, the needle is retracted, and pressure is applied to the puncture site followed by a bandage.
How Does this Blood Test Feel?
Some patients feel nothing, some feel a short pinch or sting, and only a few experience pain. Minor discomfort when the needle is inserted is common and this most often goes away right after the needle is removed. This test only takes a few minutes, so if any discomfort is experienced, it will be over very quickly.
Possible Risks of the Progesterone Blood Test
Bleed being drawn from a vein is one of the most common medical tests and there is very little risk. Patients may experience:
- A bruise at the puncture site
- Vein inflammation (rare)
- Continued bleeding if the patient takes blood-thinning medications or has a bleeding disorder (the doctor should be made aware of these before the blood is drawn)
What do the Results Mean?
If progesterone levels are high it can indicate:
- A molar pregnancy
- Adrenal gland or ovarian cancer
- Adrenal glands producing too many hormones
If progesterone levels are low it can indicate:
- Problems with ovulation
- Possible miscarriage
Lab Tests Online. (2010). Progesterone. Retrieved on July 9, 2010 from Lab Tests Online: https://www.labtestsonline.org/understanding/analytes/progesterone/test.html
WebMD. (2008). Progesterone. Retrieved on July 9, 2010 from WebMD: https://women.webmd.com/progesterone-15286
Phlebotomy Tray: Bubbels – Wikimedia Commons