Understanding Infertility

Infertility is defined as a couple's failure to conceive a child after one year of regular sexual intercourse without birth control. In about 40 percent of all cases of infertility, the problem lies with the man; in 60 percent, it lies with the woman or with both partners.

Infertility is not sterility. The term infertility implies that the condition can be treated and reversed -- that it may be a temporary problem. The term sterility is applied to a permanent, irreversible inability to have children.

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. In this article, we will examine the causes of both male and female infertility, as well as infertility diagnosis and treatment.

Causes of Male Infertility

One of the major causes of male infertility is a low sperm count. It is measured by the number of active sperm present in a milliliter (there are approximately five milliliters in one teaspoon) of semen (the fluid ejected from the penis during intercourse). An average sperm count is 90 million or more sperm per milliliter. A count of at least 40 to 60 million is thought to be necessary for fertilization; when the count is less than 20 million, it is unlikely that the man can father a child (although, since only one sperm is needed to fertilize an egg, 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).

In addition to problems with the sperm themselves, male infertility can be caused by any obstruction in the tubes that convey the sperm from the testes (the male sex organs where sperm are produced) to the penis. Infertility may also be caused by varicose veins in the scrotum (the pouch containing the testes), perhaps because the increased blood flow in these swollen veins brings extra heat to the area, or by a local infection or injury; the infertility problem will probably reverse itself when the condition is corrected.

In addition, surgical removal of part of the prostate gland (one of the organs in which most of the fluid in semen is produced), 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 the urine, rather than out through the penis).

Causes of Female Infertility

A woman may be infertile because of a variety of conditions. It may be that she is not ovulating (releasing an egg each month); this is true in about 25 percent of all cases of female infertility. The fallopian tubes (through which the eggs travel on their way from the ovaries to the uterus) may be obstructed, often as a result of pelvic inflammatory disease (PID), which irritates the tubes and causes scar tissue to form. PID can develop as a reaction to an STD or an infection of the lower reproductive tract.

Endometriosis (the displacement of tissue from the uterine lining to elsewhere in the body) may also cause the formation of scar tissue that blocks the fallopian tubes. An imbalance of the female hormones estrogen and progesterone or of other hormones secreted from the pituitary or thyroid glands can interfere with the reproductive cycle. A cervix that creates an environment that in some way prevents sperm from surviving may also be the cause of the infertility.

Now let's consider the diagnosis and treatment of infertility. It's in the next section.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

Infertility: Diagnosis and Treatment

Diagnosis of an infertility problem will usually begin with physical examinations and complete medical and sexual histories of both partners.

A fresh sample of the man's semen will be examined under a microscope to determine the quantity and quality of the sperm. The results of the exam will provide a sperm count and will also indicate whether the sperm are adequately mobile and whether the heads of the sperm are oval, both characteristics that are necessary for conception.

To determine whether ovulation is taking place in the woman, the basal body temperature (the body temperature on awakening, before eating or drinking) will be taken every morning for several months. If the temperature rises by 0.6 degrees Fahrenheit to 1.0 degrees Fahrenheit for a few days in the middle of the menstrual cycle, ovulation is probably taking place. An endometrial biopsy, in which a sample of the lining of the uterus is obtained for examination, can also indicate whether ovulation is occurring and whether hormonal secretion is normal.

Obstruction of the fallopian tubes can be diagnosed by injecting a dye into the reproductive tract and then taking an X-ray examination. Another test consists of injecting carbon dioxide gas into the fallopian tubes and waiting for the patient to feel pain in the upper part of the body, indicating that the gas is passing through the fallopian tubes and that there are no obstructions.

A cervix that creates an environment that prevents sperm from surviving can be identified by a microscopic examination of the mucus in the cervix. (The exam is performed shortly after sexual intercourse to determine the rate of sperm survival.) Endometriosis is diagnosed by inserting into the abdomen a laparoscope (a small, lighted instrument), through which the doctor can actually see the uterus, fallopian tubes, ovaries, and any displaced endometrial tissue that may be causing the infertility.

Hormonal imbalances in both men and women can be diagnosed with blood tests.

Treatment

Treatment for a low sperm count caused by a testosterone deficiency is usually hormone therapy to increase the man's testosterone levels. If the low sperm count is due to chemicals, radiation, or excess heat, exposure to these factors must be corrected or avoided. If the sperm count is low for some unknown reason, there is often little more that can be done to increase it.

Pregnancy is still possible, however. The techniques used involve artificially fertilizing an egg from the woman with sperm from the partner or from another man. The fertilization can take place inside the woman's body or outside the body, in which case the fertilized egg is then transferred into the woman's uterus.

If male infertility is caused by varicose veins, surgery may be necessary to fix the problem. If an obstruction exists somewhere in the tubes leading to and through the man's penis, microsurgery to open the blockage may be used to correct the problem.

Failure to ovulate is often treated with a fertility drug called clomiphene, which stimulates production of the hormone that regulates ovulation. About 60 percent of the patients who receive clomiphene become pregnant; the chances of multiple births are very low. A stronger drug, which is a combination of certain pituitary gland hormones, may also be prescribed, but it carries with it a greater likelihood of multiple births.

Obstructed fallopian tubes may require microsurgery to open the blockage or a procedure in which an egg is removed and replaced beyond the point of the obstruction, where it may be fertilized normally. A cervix that prevents the survival of sperm can be treated with the female hormone estrogen, which stimulates the increased production of mucus that is necessary to transport the sperm. Sometimes sperm can be placed directly into the uterus, bypassing the cervix completely. Endometriosis can be treated by the surgical removal of displaced tissue and the scar tissue that has formed around it. Hormonal imbalances can be corrected with hormone therapy.

Test-tube, or in vitro, fertilization is a technique in which an egg is removed from the woman's ovary and then placed in a test tube or special sterile dish containing the man's sperm. Once the egg has been fertilized, it is placed into the woman's uterus, where it will continue to grow. This technique is used primarily in women whose blocked fallopian tubes cannot be opened by surgery.

Another new technique used to treat infertility is called gamete intrafallopian transfer (GIFT). In this procedure, clomiphene or another fertility drug is given to the woman to stimulate ovulation. When an egg is produced by the ovary, it is removed via laparoscopy and immediately mixed with sperm from the man. This sperm-egg mixture is then transferred by laparoscopy into a fallopian tube, where fertilization may then take place normally. Fertilization occurs in the woman's body and not in a test tube. GIFT is a complicated and expensive procedure that should be used only by couples who have not been able to conceive using standard treatments for infertility.

Although recent advances in treating infertility have led to greater and greater success, about 15 percent of all female infertility problems and about 10 percent of all male problems remain undiagnosed and therefore untreatable.

Now let's consider another, very common, treatment for infertility: artificial insemination.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

The brand name products mentioned in this publication are trademarks or service marks of their respective companies. The mention of any product in this publication does not constitute an endorsement by the respective proprietors of Publications International, Ltd. or HowStuffWorks.com, nor does it constitute an endorsement by any of these companies that their products should be used in the manner described in this publication.

Artificial Insemination

Artificial insemination is the introduction of semen (the fluid containing sperm) into a woman's vagina or uterus by means other than sexual intercourse (usually with a special syringe) at or before the time of ovulation in the hope of achieving fertilization. The semen may be from the woman's partner or from a donor.

Artificial insemination using semen from the partner is sometimes done when he has a low sperm count -- that is, when there are not enough sperm per unit of fluid to be likely to fertilize an egg. To obtain enough sperm, several collections may be made over a period of days or weeks; the sperm obtained is frozen, pooled, and used in one insertion. Artificial insemination may also be used when one or the other partner cannot perform the act of sexual intercourse, perhaps because of a physical condition or an emotional problem.

Artificial insemination using semen from a donor can be an alternative to adoption when the man cannot father a child, whether because of low sperm count, absence of sperm, poor quality of sperm, lack of motion by sperm, or inability to perform sexual intercourse. It may also be considered when the man carries a genetic defect that he does not want to transmit to the child.

Now we've covered the major aspects of female and male infertility. There are many factors to consider when facing this dilemma, and it helps to be informed about all of your options.