Introduction to Infertility and Fertility Problems?

Infertility and fertility problems are common; in fact, one in every five couples who want to conceive a child are unable to do so. But improved testing procedures and treatments have enabled many couples to become parents.

Infertility is defined as a couple's failure to conceive a child after one year of regular sexual intercourse without birth control. Infertility is not sterility, which means the permanent, irreversible inability to have children. The term infertility implies that the condition can be treated and reversed.

Recent research has shown that a woman's fertility drops off significantly between the ages of 31 and 35 and continues to decline thereafter until menopause, when it ceases altogether. A man's fertility also declines after the age of 40, although men can remain fertile until old age.

One of the major causes of male infertility is a low sperm count. The sperm count is determined by measuring the number of active sperm present in a milliliter (less than a teaspoon) of semen (the fluid ejected from the penis during intercourse). An average sperm count is 90 million sperm per milliliter; a count of 40 to 60 million is thought to be necessary for conception. If a man's sperm count is less than 20 million, it is unlikely he will be able to father a child. However, it only takes one sperm to fertilize an egg, so theoretically it is still possible.

A low sperm count can be caused by low levels of testosterone (the male sex hormone); by exposure to chemicals, pesticides, or radiation; by engaging in sexual intercourse too frequently, which depletes the sperm supply too quickly; and by heat (which slows sperm production) generated by wearing tight underwear or pants, sitting for long periods in hot cars or trucks, or working near ovens and kilns.

Infertility can also result if sperm cannot propel themselves through the female reproductive tract to reach the egg, or if sperm are irregularly shaped. (Only sperm with oval-shaped heads can fertilize an egg.) It can also be caused by any obstruction in the tubes that convey the sperm from the testes to the penis; a varicocele, commonly referred to as varicose veins in the scrotum (the pouch containing the testes); or a local infection or injury.

Illustration: Teri J. McDermott, M.A., Medical Illustrator Male infertility can be caused by a blockage anywhere in the tubes that convey sperm from the testes to the penis.

Surgical removal of part of the prostate gland, as well as the use of certain drugs for high blood pressure, can lead to retrograde ejaculation, a disorder in which the semen is passed backward into the bladder, to exit with urine, rather than out through the penis during ejaculation.

Female infertility is caused by a variety of conditions, too. An imbalance of the hormones estrogen or progesterone or other hormones can interfere with the reproductive cycle. In about 25 percent of cases, the woman is not ovulating (releasing an egg each month).

Structural problems often cause infertility. The fallopian tubes, through which the egg travels from the ovary to the uterus, may be obstructed. This is often the result of pelvic inflammatory disease, which inflames the tubes and causes scar tissue formation. Endometriosis (displacement of tissue from the lining of the uterus to outside the uterus) may also cause scar tissue. A hostile cervix--one that creates an environment that prevents sperm from surviving--may also cause infertility.

Illustration: Teri J. McDermott, M.A., Medical Illustrator Female infertility can be caused by an obstruction in the fallopian tube through which the egg passes to the uterus.

Fertility problems can be caused by many factors, and a thorough evaluation is essential to diagnosis and treatment. If you're suffering from infertility or other fertility problems, consult a fertility specialist.