Progesterone

A. What it is

Fertility and menstruation are largely controlled by hormones, and one of these hormones is progesterone. Progesterone is a steroid hormone belonging to a class of hormones called progestogens. It is secreted by the corpus luteum, a temporary endocrine gland that the female body produces after ovulation during the second half of the menstrual cycle.

Progesterone is a hormone that stimulates and regulates important functions in your body, playing a big role in maintaining your pregnancy, preparing your body for conception and regulating your monthly menstrual cycle.

Progesterone is one of the hormones in our bodies that stimulates and regulates various functions. Progesterone plays a role in maintaining your pregnancy. The hormone is produced in the ovaries and then the placenta (when a woman gets pregnant) and the adrenal glands. It helps prepare your body for conception and pregnancy and regulates the monthly menstrual cycle. It also plays a role in sexual desire.

During the reproductive years, the pituitary gland in the brain generates hormones (follicle-stimulating hormone [FSH] and luteinizing hormone [LH]) that cause a new egg to mature and be released from its ovarian follicle each month. As the follicle develops, it produces the sex hormones estrogen and progesterone, which thicken the lining of the uterus. Progesterone levels rise in the second half of the menstrual cycle, and following the release of the egg (ovulation), the ovarian tissue that replaces the follicle (the corpus luteum) continues to produce estrogen and progesterone.

B. What it does

One of progesterone's most important functions is to cause the endometrium to secrete special proteins during the second half of the menstrual cycle, preparing it to receive and nourish an implanted fertilized egg. If implantation does not occur, estrogen and progesterone levels drop, the endometrium breaks down and menstruation occurs.

If a pregnancy occurs, progesterone is produced in the placenta, and levels remain elevated throughout the pregnancy. The combination of high estrogen and progesterone levels suppress further ovulation during your pregnancy. Progesterone also encourages the growth of milk-producing glands in the breast during pregnancy whether you choose to nurse your little one or not.

High progesterone levels are believed to be partly responsible for symptoms of premenstrual syndrome (PMS), such as breast tenderness, feeling bloated and mood swings. When you skip a period, it could be because of failure to ovulate and subsequent low progesterone levels.

C. Discomforts it may cause

Women who have low levels of progesterone will likely have abnormal menstrual cycles or may struggle to conceive because the progesterone does not trigger the proper environment for your conceived egg to grow. Women who have low progesterone levels and who do succeed in getting pregnant are at higher risk for miscarriage or pre-term delivery, because the hormone helps maintain the pregnancy.

Signs of low progesterone include:

• Abnormal uterine bleeding

• Irregular or missed periods

• Spotting and abdominal pain during pregnancy

• Frequent miscarriages

In addition, low progesterone levels can cause too-high levels of estrogen, which can decrease your sex drive, contribute to weight gain, or cause gallbladder problems.