Understanding Ovulatory Disorders

For women who are not ovulating regularly, the cause is usually that the ovary is not receiving the appropriately timed signals to mature and release an egg. The pituitary gland at the base of the brain produces the hormones that control the ovary – FSH (follicle stimulating hormone) and LH (luteinizing hormone). The pituitary also controls other glands around the body such as the thyroid gland and the adrenal gland. If ovulation is not occurring in a regular, timed fashion, it is likely that the ovary and the pituitary are not communicating appropriately. This may be due to abnormal levels of thyroid hormone, prolactin (another pituitary hormone) or certain adrenal hormones. If this is the case, correction of these hormone levels will restore regular ovulation and normal menstrual cycling.

For women with irregular ovulation, where the thyroid, prolactin and adrenal hormones are normal, they fall into a category called polycystic ovary syndrome (PCOS). This is actually the most common diagnosis for women with irregular ovulation – approximately 5-10 % of all reproductive age women will have this diagnosis at some point during their reproductive lifetime.

A less common cause for ovulatory dysfunction is hypothalamic amenorrhea. The pituitary gland is actually controlled by a higher center within the brain called the hypothalamus. If the hypothalamus is not communicating with the pituitary gland, then the pituitary will not be able to send the appropriate signals to the ovary to mature and release an egg.

Ovulation induction is used to help women mature and ovulate a single egg who do not ovulate regularly on their own. Superovulation is used to help patients to mature and ovulate 2-4 eggs at a time; it is used for women who may already be ovulating regularly but who have other causes for infertility such as mild male factor, one blocked fallopian tube, endometriosis, or where no specific cause has been identified (”unexplained infertility”). The chance of success with either superovulation/IUI or OI/IUI is influenced by the woman’s age and her diagnosis.

More on Ovulatory Dysfunction

Ovulatory Disorder Fact Sheet
Testing Ovarian Reserve