Progesterone clinical test significance

Reference range:

Male: 0.2-1.4 Female: Ovulation period: 0.8-3.0; Luteal phase: 1.7-27; Follicular phase: 10.2-1.5; Menopause: 0.1-0.8 μg/L

Influencing factors:

Test results may be affected when receiving estrogen and progesterone supplementation.

Clinical significance:

Progesterone is a steroid hormone that works with several other female hormones to prepare the female body for pregnancy.

Once a month, estrogen thickens and fills the endometrium (the lining of the uterus), while luteinizing hormone (LH) encourages one of the two ovaries to release an egg. The corpus luteum then forms in the ovary upon ovulation and begins to produce progesterone. These progesterones (produced in small amounts by the adrenal glands) stop the growth of the uterine lining and prepare the uterus for implantation of a fertilized egg.

If fertilization does not occur, the corpus luteum will degenerate, progesterone levels will fall, and menstrual bleeding will begin. If the fertilized egg implants in the uterus, the corpus luteum continues to produce progesterone. After a few weeks, the placenta will replace the corpus luteum as the main producer of progesterone, secreting large amounts of the hormone throughout the remainder of a normal pregnancy.

Interpreting progesterone test results requires knowledge of a woman's menstrual cycle or pregnancy. Progesterone levels usually start to rise after ovulation, continue to rise for a few days, and then either continue to rise into the first trimester, or progesterone levels drop to start the menstrual period.

If progesterone levels do not rise and fall over the course of a month, it means there is no ovulation or no menstrual cycle. Failure of progesterone levels to rise in the first trimester may indicate ectopic pregnancy or pregnancy failure. If there is no increase in levels during continuous testing for a period of time, it indicates that there may be problems with the development of the placenta and fetus.

Women with multiple pregnancies (eg, twins, triplets) have higher progesterone levels than women with singleton pregnancies.

Progesterone levels may also be elevated in luteal ovarian cysts, molar pregnancy, and some rare ovarian cancers.

Sometimes elevated progesterone levels can also be caused by overproduction of the adrenal glands.

Low levels of progesterone in late pregnancy may be related to toxaemia.