A woman's reproductive system is quite intricate and there are numerous steps that must be taken in order for a woman to become pregnant. If just one step of this process should falter, conception may fail to occur, and yet another fateful month will pass without bearing fruit. Female factor infertility is as complicated as the process of conception and there are many ways for a woman's body to betray her during her childbearing years.
Among the commonest of causes for female factor infertility are the various ovulation disorders. The term "ovulation disorders" covers a broad number of symptoms that affects around a quarter of all couples struggling to conceive. In some cases, the ovulatory dysfunction is due to an abnormality of the pituitary gland or of the hypothalamus, both of which play parts in the regulation of the reproductive hormones. In other cases, the problem has to do with the makeup of the ovary. The diagnosis of an ovulatory disorder is predicated on infrequent ovulation or the absence of ovulation (anovulation).
Two hormones are responsible for triggering ovulation each month. One hormone is known as the follicle stimulating hormone (FSH) and the second hormone is known as the luteinizing hormone (LH). Both are manufactured by the pituitary gland at some point during the normal menstrual cycle in a pattern that is, for the most part, predictable.
But this predictable pattern can be interrupted because of emotional or physical stressors or as a result of being over or underweight. Once the pattern for producing LH and FSH has been disrupted, ovulation cannot occur at the usual time and may not occur at all. The most common sign that the pattern has changed is irregular or absent menstruation.
Diseases affecting the pituitary gland can also be an obstacle to normal LH and FSH production and may cause a deficiency of other hormones, as well. In the case of polycystic ovarian syndrome (PCOS), the changes that occur within the pituitary gland, ovaries, and hypothalamus may increase levels of the male hormone androgen. High levels of this male hormone can have a severe inhibitory effect on ovulation. In addition to ovulatory dysfunction, PCOS is linked to insulin resistance and obesity.
After ovulation, the uterine lining (endometrium) begins to prepare for the reception of a fertilized egg. The hormone known as progesterone is crucial to this preparation. This stage of the menstrual cycle is called the luteal phase. If the ovary fails to manufacture sufficient progesterone to ready the endometrium, the woman is said to have a luteal phase defect.
Premature ovarian failure (POF) is another common ovulatory disorder. POF is thought to be an autoimmune response in which the body mistakes ovarian tissue for an intruder. The body attacks and obliterates the ovarian tissue. As a result, a woman's estrogen production may fall short and she may lose the eggs stored within her ovaries.