Progesterone, Serum is a blood test that measures the level of progesterone, a hormone produced by the ovaries, particularly after ovulation. Progesterone plays a key role in regulating the menstrual cycle and supporting pregnancy.

In women, progesterone levels fluctuate throughout the menstrual cycle, with levels rising after ovulation to prepare the uterus for a potential pregnancy. If pregnancy occurs, progesterone continues to be produced by the placenta to maintain the pregnancy.

This test is often used to:

• Confirm ovulation: A rise in progesterone levels typically occurs about a week after ovulation.
• Monitor early pregnancy: To check if progesterone levels are sufficient to support pregnancy.
• Assess fertility issues: Low progesterone levels can indicate problems with ovulation or potential difficulties in maintaining a pregnancy.

Progesterone levels may also be tested in men, though for different reasons, such as to evaluate adrenal or testicular function.