infertility

Definition

Infertility is the failure of a couple to conceive a pregnancy after trying to do so for at least one full year. In primary infertility, pregnancy has never occurred. In secondary infertility, one or both members of the couple have previously conceived, but are unable to conceive again after a full year of trying.

Description

Currently, in the United States, about 20% of couples struggle with infertility at any given time. Infertility has increased as a problem over the last 30 years. Some studies pin the blame for this increase on social phenomena, including the tendency for marriage to occur at a later age, which means that couples are trying to start families at a later age. It is well known that fertility in women decreases with increasing age, as illustrated by the following statistics:

• infertility in married women ages 16–20 = 4.5%
• infertility in married women ages 35–40 = 31.8%
• infertility in married women over the age of 40 = 70%.

Nowadays, individuals often have multiple sexual partners before they marry and try to have children. This increase in numbers of sexual partners has led to an increase in sexually transmitted diseases. Scarring from these infections, especially from pelvic inflammatory disease (a serious infection of the female reproductive organs, most commonly caused by gonorrhea) seems to be in part responsible for the increase in infertility noted. Furthermore, the use of some forms of the contraceptive called the intrauterine device (IUD) contributed to an increased rate of pelvic inflammatory disease, with subsequent scarring. However, newer IUDs do not lead to this increased rate of infection.

To understand issues of infertility, it is first necessary to understand the basics of human reproduction. Fertilization occurs when a sperm from the male merges with an egg (ovum) from the female, creating a zygote that contains genetic material (DNA) from both the father and the mother. If pregnancy is then established, the zygote will develop into an embryo, then a fetus, and ultimately a baby will be born.

The male contribution to fertilization and the establishment of pregnancy is the sperm. Sperm are small cells that carry the father's genetic material. This genetic material is contained within the oval head of the sperm. The sperm are mixed into a fluid called semen, which is discharged from the penis during sexual intercourse. The

whip-like tail of the sperm allows the sperm to swim up the female reproductive tract, in search of the egg it will try to fertilize.

The female makes many contributions to fertilization and the establishment of pregnancy. The ovum is the cell that carries the mother's genetic material. These ova develop within the ovaries. Once a month, a single mature ovum is produced, and leaves the ovary in a process called ovulation. This ovum enters a tube leading to the uterus (the fallopian tube). The ovum needs to meet up with the sperm in the fallopian tube if fertilization is to occur.

When fertilization occurs, the resulting cell (which now contains genetic material from both the mother and the father) is called the zygote. This single cell will divide into many other cells within the fallopian tube, and the resulting cluster of cells (called a blastocyst) will then move into the womb (uterus). The uterine lining (endometrium) has been preparing itself to receive a pregnancy by growing thicker. If the blastocyst successfully reaches the inside of the uterus and attaches itself to the wall of the uterus, then implantation and pregnancy have been achieved.

— Rosalyn Carson-DeWitt, MD

1. Absent or diminished fertility.
2. The persistent inability to conceive a child.

For more information on infertility, visit Britannica.com.

Inability to conceive or induce conception. Of all cases of infertility, 35% may be attributed to the male and 55% to the female; the remaining 10% is undetermined.

The principal cause of increasing rates of infertility is the postponement of pregnancy: adverse effects of increasing age on reproductive capacity include decreased conception rates and increased pregnancy losses. The increasing incidence of pelvic inflammatory disease is also thought to be a major cause. Pelvic infections lead to scar formation around the ovaries and the fallopian tubes, thereby impeding the transport of oocytes for fertilization.

Ovulatory dysfunction accounts for approximately 20% of cases of infertility. Ovulation is dependent on the timely secretion of the two gonadotropic hormones from the pituitary gland, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Gonadotropic hormone release can be impeded by certain medications and by many disease states, including stress, anorexia nervosa, weight loss, and thyroid disease. Anovulation can be treated by replacing the deficient gonadotropins with human menopausal gonadotropin, a mixture of follicle-stimulating and luteinizing hormones. In addition, the drug clomiphene citrate increases the endogenous secretion of those hormones from the pituitary gland. See also Pituitary gland.

Fallopian tube and uterine abnormalities account for 25% of the cases of infertile couples. These abnormalities include defective development as well as scar formation after surgery or infection. Not uncommonly the region of the fallopian tube closest to the uterus may be obstructed by scar tissue, but the obstruction can be microscopically removed or the fallopian tube can be surgically cut and reconnected.

In endometriosis, tissue that normally lines the uterus is found on the pelvic lining. Severe forms of endometriosis involve the ovaries and fallopian tubes, which doubles the likelihood of infertility in those women. The condition is treated either by surgical excision of the aberrant tissue or by subsequent medical treatment. See also Ovarian disorders.

Abnormalities in cervical mucus production may result from trauma, surgery, and diethylstilbestrol (DES) exposure before birth. The treatment of cervical abnormalities remains controversial, but may include estrogen; or another approach is to bypass this obstruction by using intrauterine transfer of semen (artificial insemination).

Male infertility resulting from abnormal semen may be due to developmental defects, genitourinary infections, or varicocele. An evaluation of sperm count, motility, and morphology is helpful, but in most cases the cause of the abnormality remains undetermined. No treatment other than donor insemination is available for these couples.

In approximately 10% of infertile couples, a thorough evaluation reveals no cause, and unexplained infertility is diagnosed. In nearly 50% of women with unexplained infertility, pelvic abnormalities are found and are most often caused by endometriosis and scar formation.

One method of assisted reproduction is in vitro fertilization, which takes place through the controlled hyperstimulation of ovulation followed by surgical extraction of mature oocytes from the ovaries. In another method of assisted reproduction, gamete intrafallopian tube transfer (GIFT), ovulation is stimulated, as with in vitro fertilization, but the extracted oocytes are placed directly into the fallopian tube with the semen specimen. Incubation occurs within the fallopian tube rather than outside the body. See also Pregnancy; Reproductive system; Reproductive system disorders; Reproductive technology.

Infertility may be primary or secondary. Primary infertility is when no pregnancy has ever occurred. Secondary infertility is when there have been one or more pregnancies but a further pregnancy has proved impossible. It has been estimated that the chances of conception for a given couple having regular sexual intercourse without any contraception are 80% and 90% after 12 months and 18 months respectively. It is therefore usual to begin investigations after one year. At this time some problems may be discovered and it should be possible, the basic tests having been done, to offer a realistic prognosis and a possible treatment outline. It is important to discover if there are any obvious abnormalities because with the new methods of treatment that have become available over the last twenty years it is frequently possible to offer real hope of success.

Female physiology

The Fallopian tubes lead from the ovaries, where the eggs are made, to the uterus. Each month, around 12-14 days from the last menstrual period, an egg (ovum) is released from the ovary. The ovum passes down the tube and its passage is facilitated by the moving cilia of the lining cells, which waft the ovum along. If intercourse occurs around this time the sperm swims up through the uterus to the tube and one of them joins the egg in the tube. The fertilized egg then continues down the tube to the uterus which has been prepared by hormones to receive the egg.

Causes of infertility

Unexplained infertility is not easy to define. The more investigations that a clinic is able to perform the lower is the incidence of unexplained infertility. Hopefully some time in the future all will be explained.

Male infertility It is not always recognized how commonly the male partner is the infertile one. The average amount of seminal fluid ejaculated each time is 2-5 ml. Persistent low volume may indicate an abnormality. If the number of sperm is less than 10 million/ml this makes fertilization less likely. The mobility of the sperm is also a factor, as is the ability of the sperm to penetrate the egg. These factors can all be tested in the laboratory. An important cause of reduced sperm numbers is a history of mumps, as the testicles are damaged in some cases.

Anovulation means that for some reason no ovum is produced in each menstrual cycle.

Tubal factors The main tubal factor is blockage, which may result from infection from sexually transmitted disease or a previous miscarriage. The blockage prevents the union of sperm and ovum so that no pregnancy occurs. Sometimes, although the tube may not be blocked, the cilia, which assist the passage of the ovum down the tube, are damaged so that the ovum gets stuck in the tube and union with the sperm does not occur. Sometimes the sperm does manage to fertilize the stuck egg and this results in a pregnancy occurring in the tube — an ectopic pregnancy. As this pregnancy grows the tube may rupture, with serious consequences due to bleeding into the abdominal cavity.

Endometriosis is a condition where, for unknown reasons, portions of the lining of the uterus grow in other parts of the pelvis such as the ovaries. The reason why this causes infertility is not clear.

Sexual dysfunction occurs sometimes due to psychological factors that prevent proper intercourse.

Mucus hostility means that the secretion from the neck of the womb (cervix) is abnormal, and kills the sperm so that they cannot travel through the uterus to the tubes.

Investigations

At an infertility clinic both partners are given a full physical examination and a detailed medical history is taken.

In the male a good proportion of infertility is due to deficiencies in semen, so a proper seminal examination is essential. This involves measurement of the volume of the ejaculate — the sperm count — which should be 20 million/ml or more; the swimming ability of the sperm; and the numbers of abnormal forms present. A history of mumps or sexually transmitted disease or genital trauma are important, as are previous hernia operations. A social history of drug and alcohol intake may be relevant, as may occupations involving working at extremes of temperature or at altitude. Physical examinations may reveal some testicular or penile abnormality.

There is still controversy as to what constitutes normal semen. With modern methods of assisted reproduction many men with very low sperm counts can produce enough sperm which can be used to fertilize eggs ‘in vitro’ (IVF). Our ideas as to what constitutes an infertile male have radically altered in the last twenty years.

In the case of the female partner the occurrence of ovulation can be tested by Basal Body Temperature measurement (the temperature rises 1 degree following ovulation in the second half of the menstrual cycle) and by measurement of the female hormones, oestrogen and progesterone. The use of ultrasound can visualize the ovum in the ovary, and taking a sample of the lining of the uterus can show whether or not the uterus is being prepared properly in each cycle for reception of a fertilized ovum. Assessment of the state of the tubes can be achieved by injecting dye through the cervix. This fills the uterine cavity, and, with the use of a small telescope (laparoscope) inserted into the abdomen, dye will be seen flowing from the tubal opening at the ovary if the tube is patent. If no dye is seen the tube is blocked. A newer method, falloscopy, involves the introduction of a tiny telescope (falloscope) into the tube through the tubal opening in the uterus and allows evaluation of the state of the tubal lining — so important for the transport of the egg. The mucus at the cervix can be sampled and tested to see if it kills sperm; if it does, there are methods of avoiding this.

A small telescope (hysteroscope) can also be used to examine the inside of the uterus to see if there any abnormalities of shape and to exclude the presence of tumours. All these tests are available at properly equipped infertility centres.

A history of pelvic infection may be relevant — perhaps after a miscarriage or previous abdominal operation, or due to sexually transmitted disease. An abnormal menstrual history may suggest a hormonal disturbance. Previous use of hormonal contraception (the Pill) can result in anovulation, and use of the intrauterine device can cause infection and blocked tubes.

The success of infertility treatment varies enormously depending on the cause. In the most favourable cases treatment may be 90% successful. In cases it may be quite unsuccessful. Nowadays, with proper investigation and treatment the results are incomparably better than a quarter of a century ago.

— Malcolm Macnaughton

See also assisted reproduction; fertility; impotence; menstrual cycle; ovum; pregnancy; testis.

noun

The state or condition of being unable to reproduce sexually: barrenness, sterility, sterilization. See reproduction/barrenness, rich/poor.

Definition

Infertility is the failure of a couple to conceive a pregnancy after trying to do so for at least one full year. In primary infertility, pregnancy has never occurred. In secondary infertility, one or both members of the couple have previously conceived, but are unable to conceive again after a full year of trying.

Description

Approximately 20% of couples struggle with infertility at any given time. Infertility has increased as a problem over the last 30 years. Some studies blame this increase on social phenomena, including the tendency for marriage and starting a family to occur at a later age. For women, fertility decreases with increasing age:

• Infertility in married women ages 16–20 = 4.5%.
• Infertility in married women ages 35–40 = 31.8%.
• Infertility in married women over the age of 40 = 70%.

Presently, individuals often have several sexual partners before they marry and try to have children. This increase in numbers of sexual partners has led to an increase in sexually transmitted diseases. Scarring from these infections, especially from pelvic inflammatory disease (infection of the female reproductive organs) seems to be in part responsible for the rise in infertility. Furthermore, use of some forms of the contraceptive called the intrauterine device (IUD) has contributed to an increased rate of pelvic inflammatory disease, with subsequent scarring. A study in 2001 found that copper IUDs have probably been wrongfully blamed for tubal infertility, while infection from the sexually transmitted disease chlamydia was likely the cause.

To understand the causes of infertility, it is first necessary to understand the basics of human reproduction. Fertilization occurs when a sperm from the male merges with an egg (ovum) from the female, creating a zygote that contains genetic material (DNA) from both the father and the mother. If pregnancy is then established, the zygote will develop into an embryo, then a fetus, and ultimately, if all goes well, a baby will be born.

Sperm are small cells that carry the father's genetic material. The sperm are mixed into a fluid called semen, which is discharged from the penis during sexual intercourse. The whiplike tail of the sperm allows the sperm to swim up the female reproductive tract, in search of an egg.

The ovum is the cell that carries the mother's genetic material. Once a month, a single mature ovum is produced, and leaves the ovary in a process called ovulation. This ovum enters a tube leading to the uterus (the fallopian tube) where fertilization occurs.

When fertilization occurs, the resulting cell (which now contains genetic material from both the mother and the father) is called the zygote. This single cell will divide into multiple cells and the resulting cluster of cells (called a blastocyst) moves into the womb (uterus). The uterine lining (endometrium) has been preparing itself to receive a pregnancy by growing thicker. If the blastocyst successfully attaches itself to the wall of the uterus, then pregnancy has been achieved.

Causes & Symptoms

Unlike most medical problems, infertility is an issue requiring the careful evaluation of two separate individuals, as well as an evaluation of their interactions with each other. In about 3–4% of couples, no cause for their infertility will be discovered. About 40% of the time, infertility is due to a problem with the male; about 40% of the time, infertility is due to the female; and about 20% of the time, there are fertility problems with both the male and the female.

The main factors involved in causing infertility include:

• male problems: 35%
• ovulation problems: 20%
• tubal problems: 20%
• endometriosis: 10%
• cervical factors: 5%

Male Factors

Male infertility can be caused by a number of different characteristics of the sperm. To check for these characteristics, a sample of semen is obtained and examined under the microscope (semen analysis). Four basic characteristics are usually evaluated:

• Sperm count refers to the number of sperm present in a semen sample. The normal number of sperm present in just 1 ml of semen is over 20 million. A man with only 5–20 million sperm is considered subfertile and a man with fewer than 5 million sperm is considered infertile.
• Sperm are also examined to see how well they swim (sperm motility) and to be sure that most have normal structure.
• Not all sperm within a specimen of semen will be perfectly normal. Some may be immature, and some may have abnormalities of the head or tail. A normal semen sample will contain no more than 25% abnormal forms of sperm.
• Volume of the semen sample is important. An abnormal amount of semen could affect the ability of the sperm to successfully fertilize an ovum.

Any number of conditions result in abnormal findings in the semen analysis. Men can be born with testicles that have not descended properly from the abdominal cavity (where testicles develop originally) into the scrotal sac, or may be born with only one instead of the normal two testicles. Testicle size can be smaller than normal. Past infection (including mumps) can affect testicular function, as can a past injury. The presence of abnormally large veins (varicocele) in the testicles can increase testicular temperature, which decreases sperm count. History of having been exposed to various toxins, drug use, excess alcohol use, use of anabolic steroids, certain medications, diabetes, thyroid problems, or other endocrine disturbances can have direct effects on the formation of sperm (spermatogenesis). A study published in late 2001 linked certain organic solvents that men encounter in the workplace as possible causes of low sperm count. The types of solvents are most likely encountered in such occupations as those of professional printers, painters, and decorators. Theories suggest solvents like glycol ethers, which are know to affect animals' reproductive systems, are the most harmful.

Problems with the male anatomy can cause sperm to be ejaculated not out of the penis, but into the bladder; and scarring from past infections can interfere with ejaculation.

Studies continue to uncover reasons for male infertility. In 2001, researchers reported that a certain protein lacking in the sperm could prevent formation of the structure on the head of the sperm that contains enzymes that help penetrate the egg, allowing conception. The finding should lead to further study of the molecular basis of male fertility.

Ovulatory Problems

The first step in diagnosing ovulatory problems is to make sure that an ovum is being produced each month. A woman's morning body temperature is slightly higher around the time of ovulation. A woman can measure and record her temperatures daily and a chart can be drawn to show whether or not ovulation has occurred. Luteinizing hormone (LH) is released just before ovulation. A simple urine test can be done to check if LH has been released around the time that ovulation is expected.

Pelvic Adhesions & Endometriosis

Pelvic adhesions cause infertility by blocking the fallopian tubes and preventing the sperm from reaching the egg. Pelvic adhesions are fibrous scars. These scars can be the result of past infections, such as pelvic inflammatory disease, or infections following abortions or prior births. Previous abdominal surgeries can also leave behind scarring.

Endometriosis is the abnormal location of uterine tissue outside of the uterus. When uterine tissue is planted elsewhere in the pelvis, it still bleeds on a monthly basis with the start of the normal menstrual period. This leads to irritation within the pelvis around the site of this abnormal tissue and bleeding, and may cause scarring. Endometriosis may lead to pelvic adhesions.

A hysterosalpingogram (HSG) can show if the fallopian tubes are blocked. This is an x-ray exam that tests whether dye material can travel through the patient's fallopian tubes. Scarring also can be diagnosed by examining the pelvic area through the use of a laparoscope that is inserted into the abdomen through a tiny incision made near the navel.

Cervical Factors

The cervix is the opening from the vagina into the uterus through which the sperm must pass. Mucus produced by the cervix helps to transport the sperm into the uterus. Injury to the cervix or scarring of the cervix after surgery or infection can result in a smaller than normal cervical opening, making it difficult for the sperm to enter. Injury or infection can also decrease the number of glands in the cervix, leading to a smaller amount of cervical mucus. In other situations, the mucus produced is the wrong consistency (perhaps too thick) to allow sperm to travel through. In addition, some women produce antibodies (immune cells) that are specifically directed to identify sperm as foreign invaders and to kill them.

Cervical mucus can be examined under a microscope to diagnose whether cervical factors are contributing to infertility. The interaction of a live sperm sample from the male partner and a sample of cervical mucus from the female partner can also be examined. This procedure is called a post-coital test.

Treatment

Conventional treatment for infertility usually involves invasive and, expensive procedures. There are many alternative treatments available that can increase the chance of conception. Some have been proven effective in clinical studies.

General measures to increase fertility include monitoring ovulation and timing intercourse (optimal chance for conception is within six days prior to and including the day of ovulation); and quitting smoking, excessive drinking, and drug use. To improve sperm quality, men can wear boxer shorts instead of briefs.

Both men and women can increase fertility by eating a well-balanced diet. Good food choices include legumes (especially soy), dark-colored vegetables, fruits, seeds, nuts, and sufficient good quality protein including meat, fish, and eggs. Some people think that refined sugar, processed cheeses, foods made with white flour, and chemical preservatives should be avoided. Adequate sleep is also important.

Supplements

Dietary supplements that can enhance fertility include:

• Multivitamins can help treat infertility in women.
• Vitamin E has antioxidant activity that prevents reproductive damage in men and women. It can increase sperm count and motility in men and balance hormones in women.
• Vitamin C has antioxidant activity that prevents reproductive damage in men and women. Also, a study found that vitamin C supplementation led to improved sperm count and decreased sperm clumping in infertile men.
• Folic acid (with a multivitamin) improved fertility in a study of infertile women.
• Zinc deficiency is often associated with low sperm count. Studies have found that zinc supplementation can improve male fertility.
• Arginine supplementation led to major increases in sperm count and motility in a study of infertile men.
• Selenium has antioxidant activity. Selenium supplementation led to increased sperm count and motility and decreased number of abnormal sperm in a study of infertile men.
• Beta-carotene supplementation can increase sperm count and motility.
• B vitamins (B₂, B₆, and B₁₂) are important for optimal fertility.

Herbal and Chinese Medicine

The following may be taken by women to treat infertility:

• Dong quai (Angelica sinensis) has been used to regulate menstrual cycles and for infertility.
• Licorice helps to balance levels of estrogen and testosterone and is used for infertility.
• Red clover (Trifolium pratense) has a beneficial effect on the uterus, can calm the nervous system, and can balance hormone levels.
• Nettle (Urtica dioica) supports the uterus and hormonal system.
• Raspberry leaf strengthens the mucous lining of the uterus.
• Chasteberry (Vitex agnus-castus) balances hormone production.
• Ladies mantle (Alchemilla vulgaris) balances hormone production.
• Shatavari (Asparagus racemosus) is an Ayurvedic remedy for infertility and works by balancing hormones.
• Rehmannia is an Ayurvedic remedy for infertility.
• Myrrh (Commiphora myrrha) is an Ayurvedic remedy for infertility.
• False unicorn (Chamaelirium luteum) balances hormone levels.
• Pomegranate essence balances the reproductive system.

The following may be taken by men to treat infertility:

• Ginseng may increase the formation of sperm, testosterone levels, and sexual activity.
• Pygeum may help infertile men who have a reduced secretion of semen.
• Pine bark extract improves sperm shape.
• Chasteberry (Vitex agnus-castus) balances hormone production.
• Shatavari (Asparagus racemosus) is an Ayurvedic remedy for infertility and works by balancing hormones. May increase sperm production.
• Saw palmetto (Serenoa serrulata) increases the production of testosterone and strengthens the reproductive system.
• Ashwaganda (Withania omnifera) is an Ayurvedic remedy that improves the quality of semen and sperm count.
• Chinese herbals must be specifically designed and used to treat infertility in males.

Other Treatments

A variety of other alternative treatments may be used for infertility:

• stress reduction
• cognitive behavior therapy
• visualization
• homeopathy
• reflexology
• essential oils
• acupuncture

Allopathic Treatment

The first step in the treatment of infertility is to perform thorough physical exams and testing of both partners in the hope of finding the source of infertility. For the woman this involves blood testing and ultrasound examinations at specific days during the menstrual cycle. This may include an endometrial biopsy in which a sample of the lining of the uterus is taken and examined. Hysteroscopy, in which a special camera examines the inside of the uterus, may be performed.

Pelvic adhesions can be treated during laparoscopy. The adhesions are cut using special instruments. Endometriosis can be treated with certain medications, but may also require surgery to repair any obstruction caused by adhesions.

Treatment of cervical factors includes antibiotics in the case of an infection, steroids to decrease production of anti-sperm antibodies, and artificial insemination techniques to completely bypass the cervical mucus.

Treatment of ovulatory problems depends on the cause. If a thyroid or pituitary problem is responsible, simply treating that problem can restore fertility. Medications that stimulate ovulation are clomiphene citrate (Clomid) that is taken by mouth and follicle stimulating hormone (Pergonal, Fertinex, and Follistim) that is given by injection. These drugs increase the risk of multiple births (twins, triplets, etc.) and may cause side effects.

Treatment of male infertility includes addressing known reversible factors first; for example, discontinuing any medication known to have an effect on spermatogenesis or ejaculation, as well as decreasing alcohol intake, and treating thyroid or other endocrine disease. Varicoceles can be treated surgically. Testosterone in low doses can improve sperm motility.

Other treatments of male infertility include collecting semen samples from multiple ejaculations, pooling them, and depositing them into the female's uterus during ovulation. When the male partner's sperm is proven to be absolutely unable to produce pregnancy, donor sperm may be used. Depositing the male partner's sperm or donor sperm by mechanical means into the female is called artificial insemination.

Assisted reproductive techniques include in vitro fertilization (IVF), gamete intrafallopian transfer (GIFT), and zygote intrafallopian tube transfer (ZIFT). These are usually used after other techniques to treat infertility (surgery, medications, and/or insemination) have failed.

IVF involves the use of drugs to induce the simultaneous production of many eggs from the ovaries, which are retrieved surgically or via ultrasound-guided needle aspiration through the vaginal wall. The ova and sperm are combined in a laboratory, where several of the ova may be fertilized. Cell division is allowed to take place up to the pre-embryo stage. While this takes place, the female may be given progesterone to ensure that her uterus is ready for implantation. Two or more pre-embryos are transferred to the female's uterus.

Success rates of IVF are still rather low. The national average success rate of IVF is approximately 27% but some centers have higher pregnancy rates. Because most IVF procedures put more than one embryo into the uterus, the chance for a multiple birth (twins or more) is greatly increased.

GIFT involves retrieval of both multiple ova and semen, and the mechanical placement of both within the female's fallopian tubes, where fertilization may occur. ZIFT involves the same retrieval of ova and semen, and fertilization and growth in the laboratory up to the zygote stage, at which point the zygotes are placed in the fallopian tubes. Both GIFT and ZIFT have higher success rates than IVF.

Expected Results

In general, it is believed that about half of the couples who undergo a complete evaluation of infertility followed by treatment will ultimately have a successful pregnancy. About 5% of those couples who choose to not undergo evaluation or treatment will go on to conceive after a year or more.

Resources

Books

Hornstein, Mark D., and Daniel Schust. "Infertility." In Novak's Gynecology, edited by Jonathan S. Berek. Baltimore: Williams and Wilkins, 1996.

Maleskey, Gale. "Infertility." Nature's Medicines: from Asthma to Weight Gain, from Colds to High Cholesterol—the Most Powerful All-Natural Cures. Emmaus, PA: Rodale Press, 1999.

Martin, Mary C. "Infertility" In Current Obstetric and Gynecologic Diagnosis and Treatment, edited by Alan H. Cecherney and Martin L. Pernoll. Norwalk, CT: Appleton & Lange, 1994.

Ying, Zhou Zhong, and Jin Hui De. "Common Diseases of Gynecology." In Clinical Manual of Chinese Herbal Medicine and Acupuncture. New York: Churchill Livingston, 1997.

Periodicals

Alfieri, Rosemarie Gionta. "Natural Options for Fertility." Let's Live, 67 (May 1999): 37+.

"Copper IUD Not the Cause of Tubal Occlusion." Contemporary OB/GYN 46, no. 12 (December 2001): 111.

"Low Sperm Count Linked to Organic Solvents." Health and Medicine Week (October 1, 2001).

"New Study Provides Insight into Male Infertility." Gene Therapy Weekly (December 13, 2001).

Rosenbaum, Joshua. "Beat the Clock: Treatments for Infertility." American Health (December 1995): 70+.

Trantham, Patricia. "The Infertile Couple." American Family Physician (September 1, 1996): 1001+.

Veal, Lowana. "Complementary Therapy and Infertility: an Icelandic Perspective." Complementary Therapies in Nursing & Midwifery 4 (1998): 3–6.

Organizations

American Society for Reproductive Medicine. 1209 Montgomery Highway, Birmingham, AL 35216-2809. (205) 978-5000. .

International Center for Infertility Information Dissemination. .

RESOLVE. 1310 Broadway, Somerville, MA 02144-1779. (617) 623-1156. .

[Article by: Belinda Rowland; Teresa Norris]

Inability of a woman to conceive or of a man to induce conception. Strenuous regular physical activity of more than 1 h each day may be a factor contributing to the infertility of some women since such activity can disrupt menstruation (see amenorrhoea) and it may even prevent ovulation in some women. The abuse of certain drugs as ergogenic substances may also lead to infertility. For example, anabolic steroids can cause testicular atrophy, which may lead to infertility because of lack of sperm. Usually, this situation is resolved after withdrawal of the drugs, but the sperm count may remain abnormally low for 12-24 months.

The inability to conceive and produce viable offspring. In agricultural animals there are requirements that the animals reproduce prolifically and at a particular time chosen to best suit the availability of feed. A decision as to when infertility can be said to be present varies with the species and with the mating pair, and also with the state of the environment. For example, a dairy cow mated three times without conceiving to proven fertile semen by artificial insemination or by natural breeding to a known fertile bull is judged to require treatment for infertility. Infertility is a diagnosis about a mating rather than an individual animal; the error may be with the male or the female and it may be permanent or temporary. As a herd problem it provides a major brake on production in all species. In many instances the problem is man-made and in many of those there is in fact nothing wrong with the animals but there is with the management program, especially the nutritional regimen, which affects a mating at a time when fertility is marginal.

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