Progesterone - Human Antiaging Center

What is Progesterone?

Progesterone is an important hormone that plays a vital role in the female menstrual cycle and pregnancy. It is a steroid hormone produced mainly by the corpus luteum in the ovary after ovulation, and by the placenta during pregnancy.

Key Functions of Progesterone

Some of the main functions of progesterone include:

• Preparing the uterus for pregnancy - It helps build up the lining of the uterus to support a fertilized egg and early embryo development.
• Maintaining pregnancy - It helps maintain pregnancy by promoting uterine quieting and preventing rejection of the embryo.
• Developing breast tissue - It promotes development of the mammary glands during puberty and pregnancy to allow for future breastfeeding.
• Regulating the menstrual cycle - Along with estrogen, it controls the timing and end of the menstrual cycle. If an egg is not fertilized, progesterone levels drop, causing menstruation.

Changes Throughout the Menstrual Cycle

• During the follicular phase (days 1-14), progesterone levels are low while estrogen levels rise to mature an egg.
• After ovulation on about day 14, progesterone is secreted by the corpus luteum. Progesterone levels rise significantly during the luteal phase to prepare the uterus lining.
• If no pregnancy occurs, both progesterone and estrogen levels drop in the late luteal phase, triggering menstruation and the next cycle.

Role in Pregnancy

If pregnancy occurs:

• The corpus luteum continues secreting progesterone to maintain the uterine lining and support early pregnancy.
• After 8-10 weeks, the placenta takes over progesterone production. Levels continue rising steadily during pregnancy.
• Progesterone has anti-inflammatory and immune-suppressant effects to prevent rejection of the fetus.
• It helps suppress secretion of hormones that cause uterine contractions.
• It also promotes fetal development and prevents early birth.

So in summary, progesterone is the key pregnancy-sustaining hormone. It has wide-ranging impacts on the female reproductive system, from regulating ovulation to preparing for and maintaining a pregnancy through several mechanisms. It works closely with estrogen to modulate the menstrual cycle. Monitoring progesterone levels is important during infertility treatment and high-risk pregnancies at Human Antiaging Center.