Amenorrhea

Amenorrhea overview

• Amenorrhea is the absence of a woman’s menstrual period, either permanently or temporarily.
• Missing one menstrual period is rarely a sign of a serious problem or medical condition, but amenorrhea for a long period of time may be a sign of a disease or chronic condition that could be contributing to infertility.

What causes amenorrhea?

Fluctuating levels of hormones drive the normal menstrual cycle. Ovaries are stimulated by hormones from the pituitary gland, which is controlled by hormones produced in the hypothalamus of the brain. Disorders that affect this part of the regulatory process can lead to conditions such as amenorrhea.

In addition to changes in hormone levels, the menstrual cycle can be influenced by stress and illness. Missing one menstrual period is rarely a sign of a serious problem or medical condition, but amenorrhea for several months may be a sign of a disease or chronic condition that can contribute to infertility.

Primary amenorrhea

Primary amenorrhea is generally a result of a genetic or anatomic condition in young women who never develop menstrual periods and are not pregnant. Some or all of the female organs either fail to form during fetal development or never reach full function in puberty. Problems with the pituitary gland and hypothalamus can also cause primary amenorrhea since these parts of the body are a part of regulating ovarian hormones.

Gonadal dysgenesis is a condition of premature ovaries leading to depleted follicles and eggs (oocytes) that causes unsuccessful ovary function. Gonadal dysgenesis is one of the more common causes of primary amenorrhea in young women.

Women who are carriers of Turner syndrome lack part or all of one of the two X chromosomes normally present in females. The ovaries are unable to produce estrogen, resulting in amenorrhea.

Other conditions that may result in primary amenorrhea include: androgen insensitivity, congenital adrenal hyperplasia and polycystic ovary syndrome (PCOS).

Secondary amenorrhea

The most common – and obvious – cause of secondary amenorrhea is pregnancy. Additional causes of secondary amenorrhea include conditions that affect the ovaries, uterus, hypothalamus or pituitary gland.

Hypothalamic amenorrhea is caused by a disruption in the hormones produced by the hypothalamus in the brain that help regulate menstruation. These hormones affect the pituitary gland, which in turn signals the ovaries to produce the necessary cyclic hormones. Several conditions can affect the hypothalamus such as extreme weight loss, emotional stress, intensive exercise, severe illness or physical stress.

Other causes of secondary amenorrhea include:

• Elevated levels of male hormones (androgens)
• Premature ovarian failure or early menopause
• Tumors or other diseases that affect the pituitary gland, which can lead to increased levels of prolactin
• PCOS
• Asherman’s syndrome, which is a uterine disease that results in scarring of the uterine lining