Progesterone - Serum

Description

A progesterone test measures the level of progesterone in a sample of your blood. Progesterone is a hormone that's made mainly by the ovaries, which are two glands in the female reproductive system that contain eggs.

Each month, progesterone prepares your uterus for pregnancy. During a normal menstrual cycle, an ovary releases an egg and your progesterone levels begin to rise. Progesterone makes the lining of your uterus grow thicker so that a fertilized egg can attach (implant) inside of the uterus and grow into a baby.

If you don't become pregnant, your progesterone levels will fall. The lining of your uterus will become thinner again. When your uterus starts to get rid of the extra blood and tissue, your menstrual period will begin.

If you become pregnant, progesterone levels will continue to rise to about 10 times higher than usual to support the pregnancy. High levels of progesterone prevent the uterus from contracting (squeezing) and causing pre-term labor. Much of the progesterone you need for a healthy pregnancy is made by the placenta. The placenta is the organ that grows in the uterus to provide nutrients and oxygen to the unborn baby.

A progesterone test can help show whether low progesterone levels are causing female infertility (problems getting pregnant after a year of trying) or problems during pregnancy. The test may also help diagnose certain problems with the adrenal glands that may cause high levels of progesterone in both females and males.

Other names: serum progesterone, progesterone blood test, PGSN.

Source: National Institutes of Health (NIH) U.S. Department of Health and Human Services.