To help recognize and manage some causes of infertility. Since progesterone levels vary throughout the menstrual cycle, multiple (serial) measurements can be used for this purpose.
To determine whether or not a woman has ovulated, when ovulation occurred, or to monitor the success of induced ovulation
To monitor a high-risk pregnancy to help evaluate placenta and fetal health
If a woman is receiving progesterone injections to help support her early pregnancy, to help determine the effectiveness of the replacement treatment
Along with other tests such as an FSH, LH, hCG, thyroid tests, clotting tests, and a complete blood count (CBC) to help determine the cause of abnormal uterine bleeding in non-pregnant women
When is it ordered?
Progesterone levels are measured:
During an infertility assessment, when a woman is having trouble getting pregnant and her health care provider wants to verify that she is ovulating normally; the test may be ordered a few times during a woman's menstrual cycle to evaluate the change in progesterone concentrations.
When it is necessary to determine when ovulation has occurred and following drug therapy to induce ovulation
When symptoms, such as abdominal pain and spotting, suggest an ectopic pregnancy or threatened miscarriage
On a regular basis when a woman requires progesterone replacement therapy to help maintain her pregnancy
Periodically throughout a high-risk pregnancy to monitor placenta and fetal health
When a non-pregnant woman is experiencing abnormal uterine bleeding
What does the test result mean?
Interpretation of progesterone test results depends on the reason for testing and requires knowledge of the point at which a woman is in her menstrual cycle orpregnancy. Progesterone levels usually start to elevate when an egg is released from the ovary, rise for several days, and then either continue to rise with early pregnancy or fall to initiate menstruation.
If progesterone levels do not rise and fall on a monthly basis, a woman may not be ovulating nor having regular menstrual periods. This may be a cause of infertility.
If levels do not rise normally during an early pregnancy, the pregnancy may be ectopic and/or may be failing. If serial measurements do not show increasing progesterone levels over time, there may be problems with the viability of theplacenta and fetus.
Increased progesterone levels are seen occasionally with:
Levels of progesterone will be naturally higher during pregnancies that involve multiples (twins, triplets, etc.) than those in which there is only one fetus.
Taking estrogen and progesterone supplements can affect results.
Men will also have small amounts of progesterone in their blood.
A limited number of laboratories can perform progesterone testing on saliva.