Male infertility

Ovulatory disorders

The most common causes of infertility include the inability to ovulate (anovulation) and irregular ovulatory cycles (oligoovulation). The causes of these types of ovulatory disorders are quite diverse, and may include problems with the central nervous system or pituitary gland, as well as complications with the developing follicles, ovary, or both.

Common ovulatory disorders include:

Hypothalamic-pituitary problems
Premature ovarian failure
Polycystic ovarian disease, chronic anovulation, and related syndromes

Hypothalamic-pituitary problems

Some women do not ovulate because there is little or no stimulation from their pituitary glands. This can affect the functioning of the hypothalamus (the part of the central nervous system which communicates with the pituitary gland). This is a common problem for women who exercise vigorously, are under significant stress, or who have eating disorders such as anorexia. These women do not produce sufficient follicle-stimulating hormone (FSH) and luteinizing hormone (LH) to stimulate the follicles in the ovaries to mature. Treatment involves either stimulating the pituitary to release LH and FSH or simply replacing the missing LH and FSH by administering it directly.

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Premature ovarian failure

Some women do not ovulate because they have few or no eggs in their ovaries. When this happens prior to the age of 40, it is termed premature ovarian failure (POF) or premature menopause. This could be the result of prior chemotherapy or radiation therapy, prior removal of the ovaries, or various genetic abnormalities. However, often the explanation is not obvious and these women may have simply exhausted their supply of eggs at a very young age. Since these women do not have viable eggs they are not candidates for ovulation induction.

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Polycystic ovarian disease, chronic anovulation, and related syndromes

A vast majority of women who do not ovulate regularly have a pituitary gland that is functional and have plenty of eggs containing follicles in their ovaries. The problem stems from the relationship between the stimulatory effects of the LH and FSH released from the pituitary and how the follicles respond. While the source of this problem varies and is not known for many patients, the symptoms resemble those associated with polycystic ovarian disease (PCO). They include multiple small follicles within the ovary and abnormal levels of LH and FSH in the blood stream.

Although the cause of these disorders and the symptoms vary from patient to patient, a common finding is that these women lack sufficient FSH stimulation to keep their follicles developing to maturity. In many cases treatment focuses on raising FSH levels to the point where follicular growth and development resumes, resulting in the release of a healthy mature egg (ovulation).

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