The amount of women who cannot become pregnant in the United States is estimated to be over three million. The trouble of infertility seems to be tackling more women than ever before and according to the Federal Centers for Disease Control, this increase is partially attributable to an increase in sterility-causing diseases. For example, between 1965 and 1976, reported cases of gonorrhea tripled. By the late 1970s, penicillin-resistant gonorrhea had become a major public health problem and unfortunately not until the 1980s did infectious disease experts realize the full extent of the fertility problems caused by Chlamydia. During the same decade, there was a six hundred percent increase in the number of women using IUDs, which put them at increased risk for pelvic inflammatory disease, a major cause of infertility.

According to a 1985 infertility study, as many as 88,000 women may be unable to conceive because of infections that occurred while they were wearing an IUD. The drop in fertility has also been attributed to the postponement of pregnancy into the thirties because of career demands or because of uncertainty about the long-term stability of the spousal relationship.

Specifically, abnormalities of the fallopian tubes, including scarring from endometriosis or previous infections, surgery or swelling from a current infection account for about twenty to thirty percent of all infertility problems. Problems with ovulation are thought to be the cause of infertility in about ten to fifteen percent of all cases. Chronic diseases such as thyroid disease, uncontrolled diabetes, or liver disease usually cause infertility by interfering with the complex mechanism of ovulation. In approximately five percent of the cases, there is a problem with the cervix or cervical mucus. Other factors include on-the-job exposure to chemicals and radiation and sustained strenuous exercise, such as marathon running, which can cause temporary (that is reversible) infertility in some women even though their menstrual cycles may continue to be normal.

Endometriosis is a condition in which tissue that looks like eudiometrical tissue (the tissue that lines the uterus and is shed each month in menstruation) is located out side the uterus. It is also called endometritis (disorder of the uterus) and cause lower abdominal pain. It is uncertain whether this develops from a backflow of eudiometrical tissue during menstruation into and beyond the fallopian tubes or from an "embryological mistake" whereby eudiometrical cells develop in an incorrect location. Endometriosis is usually located only on the pelvic organs surrounding the uterus, but in rare instances it can be found in other places such as the upper abdomen or lung.

These areas of endometriosis may bleed at the time of the menstrual period just as the uterine endomentrium does. This may cause pain and because there is no way for the blood to escape, scarring may develop. This scarring may seal off the ovaries and prevent the egg from reaching the fallopian tube. Even if there are only small areas of endometriosis and the tubes and ovaries are not completely blocked, fertility may be reduced.