What is Progesterone?

Progesterone, also known as luteal hormone or progestogen, is an important hormone in pregnant women's bodies, mainly secreted by the ovarian corpus luteum and placenta, and primarily involved in regulating the functions of the reproductive system.

Progesterone helps maintain pregnancy by inhibiting contractions of the uterine smooth muscle, reducing uterine excitability, and providing a safe and stable growth environment for the fetus. It also works together with estrogen to promote the development of mammary alveoli, preparing for lactation after childbirth. Progesterone can reduce contractions of the uterine muscles and prevent premature birth. Additionally, progesterone participates in regulating the female menstrual cycle, influences breast development, and affects the maternal immune system to some extent, avoiding rejection of the embryo.

Progesterone testing mainly includes blood tests and urine tests, with blood testing being the most commonly used method. The normal reference range varies depending on a woman's physiological stage. If progesterone levels are abnormal, it may affect a woman's fertility and even lead to adverse outcomes such as miscarriage. Pregnant women with a risk of miscarriage or luteal phase deficiency may be advised by their doctors to take progesterone supplements to support the pregnancy.