Infertility

Understanding female infertility and its causes

By Michael Russell

The number of women who cannot become pregnant in the United States is estimated to be over three million. Infertility seems to be affecting more women than ever before. An increase in sexually transmissible infections, widespread use of intrauterine contraceptive devices and the increase in elective abortions are all thought to play a role. The infections include gonorrhea, chlamydia, and pelvic inflammatory disease. 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 600 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 using an IUD. Women with intrauterine contraceptive devices may have chronic low-grade infections and some may develop an acute severe infection or a pelvic abscess. Though severe pelvic infection was more common before abortions were legal, a mild infection is not unheard of after an elective abortion today. A ruptured appendix may also cause pelvic infection and scarring of the fallopian tubes. Pelvic adhesions may occur after surgery to remove ovarian cysts, fibroids, and tubal pregnancies or after any other lower abdominal or pelvic surgery.

The drop in fertility has also been linked to the postponement of pregnancy into the 30s 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 20 to 30 percent of all infertility problems.

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.

Problems with ovulation are thought to be the cause of infertility in about 10 to 15 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 5 percent of 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.

Infertility related to tubal blockage and pelvic adhesions is on the rise. Irregularities in the shape of the uterus can occasionally cause infertility, although they are more frequently associated with spontaneous abortions (miscarriages) than with the inability to conceive. The most common cause of irregularity in the shape of the uterus is fibroids (benign fibrous growths of the uterus). Other causes are congenital or developmental abnormalities. Recently some abnormalities in the shape of the uterus have been found in daughters of women who took the drug diethylstilbestrol (DES) during pregnancy.

Both hypothyroidism (underproduction of the hormone thyroxin that is stored in the glandular follicles and released into the bloodstream as needed for the regulation of the metabolic rate) and hyperthyroidism (overproduction of the hormone thyroxin) and other hormonal abnormalities may cause infertility by unbalancing the delicate and complex regulation of the menstrual cycle. Severe illness of any sort (diabetes, liver disease) can also affect the normal cycle and cause infertility.

A vaginal infection may alter the cervical mucus and the pH of the vagina, creating a hostile environment in which the sperm may be able to live for only a very short time. The presence of sperm antibodies in cervical mucus or vaginal secretions may cause infertility. There is controversy among physicians about how often this may be a factor because these antibodies may be found in people with normal fertility. In some couples, however, these antibodies appear to kill or inactivate the sperm.

There is a significant number of infertile couples who complete all of the standard testing without any obvious cause of infertility. Many of these couples eventually conceive. Unfortunately, some remain infertile. However, with advances infertility testing, fewer and fewer cases of infertility remain unexplained.

Timing of intercourse is important. A woman with a twenty-eight-day cycle should have intercourse daily from the tenth to the fourteenth day of her menstrual cycle. These are the days of her maximum fertility. A male with a low sperm count should get special intercourse timing instructions, as should the woman with a shorter or longer cycle.

Position during intercourse may also be important. Sperm may reach the cervix more easily when the woman, lying on her back, draws her knees up to encircle her partner's hips. After his orgasm, the woman should maintain this position for ten to fifteen minutes or relax with a pillow under her hips.