If you've tried to conceive for more than a year, you or your partner may be infertile. Pregnancy may be a challenge, not an impossibility.
Infertility, also known as subfertility, is the inability to conceive a child within one year. Infertility may be due to a single cause in either you or your partner, or a combination of factors that may prevent a pregnancy from occurring or continuing.
Infertility differs from sterility. Being sterile means you're unable to conceive a child. With sterility, you or your partner has a physical problem that precludes the ability to conceive. A diagnosis of infertility simply means that becoming pregnant may be a challenge rather than an impossibility.
The human reproductive process is complex. To accomplish a pregnancy, the intricate processes of ovulation and fertilization need to work just right. For many couples attempting pregnancy, something goes wrong in one or both of these complex processes and causes infertility.
Infertility affects more than 6 million American couples, with the male partner being either the sole or a contributing cause in approximately 40 percent of infertile couples. Problems with female fertility are present about one-half to two-thirds of the time. In both men and women, multiple factors can account for difficulty with fertility.
Signs and symptoms
Most men with fertility problems have no signs or symptoms. Some men with hormonal problems may note a change in their voice or pattern of hair growth, enlargement of their breasts, or difficulty with sexual function. Infertility in women may be signaled by irregular menstrual periods or associated with conditions that cause pain during menstruation or intercourse.
Because of the intricate series of events required to begin a pregnancy, many factors may cause a delay in starting your family.
Every month the pituitary gland in a woman's brain sends a signal to her ovaries to prepare an egg for ovulation. The pituitary hormones — follicle-stimulating hormone (FSH) and luteinizing hormone (LH) — are involved in stimulating the ovaries to bring an egg to ovulation. A large boost in LH carries a message to the ovarian follicle to release its egg (ovulate). A woman is most fertile at the time of ovulation — around day 14 of her menstrual cycle — although the exact time of ovulation varies among women due to different lengths of menstrual cycles.
Every month, hormones signal a woman's ovaries to prepare an egg for ovulation....During each menstrual cycle, an egg is released by one of the ovaries (ovulation). The egg travels into the fallopian tube. If fertilization is to occur, sperm ejaculated into the vagina must swim up ...For fertilization to occur, sperm produced in the testicles and ejaculated into the vagina must swim up the uterus and into the fallopian tube where one sperm penetrates the egg....
The egg is then captured by a fallopian tube and is viable for about 24 hours, but its best chance of being fertilized is within the first 12 hours following ovulation. For pregnancy to occur, a sperm must unite with the egg in the fallopian tube within this time. Sperm are capable of fertilizing the egg for up to 72 hours and must be present in the fallopian tube at the same time as the egg for conception to occur. If fertilized, the egg moves into the uterus two to four days later. There it attaches to the uterine lining and begins a nine-month process of growth.
In order for sperm to reach the egg, many factors are involved in the male fertility process. There must be enough sperm, they must be of the right shape, and they must move in the right way. There must be enough semen to transport the sperm. The man also needs to be able to have an erection, and must be able to ejaculate the semen and deliver it into the vagina.
The cause of infertility can involve one or both partners. Sometimes the problem isn't really one of infertility, but a more general sexual problem such as erectile dysfunction. Other times, the problem may involve an abnormality in the structure of the reproductive hormones or organs. Certain infections and diseases also can affect fertility.
A number of causes exist for male infertility that may result in impaired sperm count or mobility, or impaired ability to fertilize the egg. The most common causes of male infertility include abnormal sperm production or function, impaired delivery of sperm, conditions related to a man's general health and lifestyle, and overexposure to certain environmental elements:
Abnormal sperm production or function. More than 90 percent of male infertility cases are due to sperm abnormalities, such as:
Impaired shape and movement of sperm. Sperm must be properly shaped and able to move rapidly and accurately toward the egg for fertilization to occur. If the shape and structure (morphology) of the sperm is abnormal or the movement (motility) is impaired, sperm may not be able to reach the egg.
Absent sperm production in testicles. Complete failure of the testicles to produce sperm is rare, affecting less than 5 percent of infertile men.
Low sperm concentration. A sperm count of 13.5 million per milliliter of semen or fewer indicates low sperm concentration (subfertility). A count of 48 million per milliliter of semen or higher indicates fertility.
Varicocele. A varicocele is a varicose vein in the scrotum that may prevent normal cooling of the testicle and raise testicular temperature, preventing sperm from surviving.
Undescended testicle (cryptorchidism). This occurs when one or both testicles fail to descend from the abdomen into the scrotum during fetal development. Undescended testicles can cause mild to severely impaired sperm production. Because the testicles are exposed to the higher degree of internal body heat, sperm production may be affected.
Testosterone deficiency (male hypogonadism). Infertility can result from disorders of the testicles themselves, or an abnormality affecting the hypothalamus or pituitary glands in the brain that produce the hormones that control the testicles.
Klinefelter's syndrome. In this disorder of the sex chromosomes, a man has two X chromosomes and one Y chromosome instead of one X and one Y. This causes abnormal development of the testicles, resulting in low or absent sperm production. Testosterone production also may be lower.
Infections. Infection may temporarily affect sperm motility. Repeated bouts of sexually transmitted diseases (STDs), such as chlamydia and gonorrhea, are most often associated with male infertility. These infections can cause scarring and block sperm passage. Mycoplasma is an organism that may fasten itself to sperm cells, making them less motile. If mumps, a viral infection usually affecting young children, occurs after puberty, inflammation of the testicles can impair sperm production. Inflammation of the prostate (prostatitis), urethra or epididymis also may alter sperm motility.
In many instances, no cause for reduced sperm production is found. When sperm concentration is less than 5 million per milliliter of semen, genetic causes could be involved. A blood test can reveal whether there are subtle changes in the Y chromosome.
Impaired delivery of sperm. Problems with the delivery of sperm from the penis into the vagina can cause infertility. These may include:
Sexual issues. Often treatable, problems with sexual intercourse or technique may affect fertility. Difficulties with erection of the penis (erectile dysfunction), premature ejaculation, painful intercourse (dyspareunia), or psychologic or relationship problems can contribute to infertility. Use of lubricants such as oils or petroleum jelly can be toxic to sperm and impair fertility.
Retrograde ejaculation. This occurs when semen enters the bladder during orgasm rather than emerging out through the penis. Various conditions can cause retrograde ejaculation including diabetes, bladder, prostate or urethral surgery, and the use of psychiatric or antihypertensive drugs.
Blockage of epididymis or ejaculatory ducts. Some men are born with blockage of the part of the testicle that contains sperm (epididymis) or ejaculatory ducts. An estimated 2 percent of men who seek treatment for infertility lack the tubes that carry sperm (vas deferens).
No semen (ejaculate). The absence of ejaculate may occur in men with spinal cord injuries or diseases. This fluid transports sperm through the penis into the vagina.
Misplaced urinary opening (hypospadias). A birth defect can cause the urinary (urethral) opening to be abnormally located on the underside of the penis. If not surgically corrected, this condition can prevent sperm from reaching the cervix.
Antisperm antibodies. Antibodies that target sperm and weaken or disable them usually occur after surgical blockage of part of the vas deferens for male sterilization (vasectomy). Presence of these antibodies may complicate the reversal of a vasectomy.
Cystic fibrosis. Men with cystic fibrosis often have missing or obstructed vas deferens.
General health and lifestyle. A man's general health and lifestyle may affect fertility. Some common causes of infertility related to health and lifestyle include:
Emotional stress. Stress may interfere with certain hormones needed to produce sperm. Your sperm count may be affected if you experience excessive or prolonged emotional stress. A problem with fertility itself can sometimes become long term and discouraging, producing more stress. Infertility can affect social relationships and sexual functioning.
Malnutrition. Deficiencies in nutrients such as vitamin C, selenium, zinc and folate may contribute to infertility.
Obesity. Increased body mass may be associated with fertility problems in men.
Cancer and its treatment. Both radiation and chemotherapy treatment for cancer can impair sperm production, sometimes severely. The closer radiation treatment is to the testicles, the higher the risk of infertility. Removal of one or both testicles due to cancer also may affect male fertility. You may want to consider freezing (cryopreserving) your sperm before cancer treatment to ensure future fertility.
Alcohol and drugs. Alcohol or drug dependency can be associated with general ill health and reduced fertility. The use of certain drugs also can contribute to infertility. Anabolic steroids, for example, which are taken to stimulate muscle strength and growth, can cause the testicles to shrink and sperm production to decrease.
Other medical conditions. A severe injury or major surgery can affect male fertility. Certain diseases or conditions, such as diabetes, thyroid disease, HIV/AIDS, Cushing's syndrome, anemia, heart attack, and liver or kidney failure, may be associated with infertility.
Age. A gradual decline in fertility is common in men older than 35.
Environmental exposure. Overexposure to certain environmental elements such as heat, toxins and chemicals can reduce sperm count either directly by affecting testicular function or indirectly by altering the male hormonal system. Specific causes include:
Pesticides and other chemicals. Herbicides and insecticides may cause female hormone-like effects in the male body and may be associated with reduced sperm production. Exposure to such chemicals also may contribute to testicular cancer. Men exposed to hydrocarbons, such as ethylbenzene, benzene, toluene, xylen and aromatic solvents used in paint, varnishes, glues, metal degreasers and other products, may be at risk of infertility. Men with high exposure to lead also may be more at risk.
Testicular exposure to overheating. Frequent use of saunas or hot tubs can elevate your core body temperature. This may impair your sperm production and lower your sperm count.
Substance abuse. Cocaine or heavy marijuana use may temporarily reduce the number and quality of your sperm.
Tobacco smoking. Men who smoke may have a lower sperm count than do those who don't smoke.
The most common causes of female infertility include fallopian tube damage or blockage, endometriosis, ovulation disorders, elevated prolactin, polycystic ovary syndrome, early menopause, benign uterine fibroids, and pelvic adhesions:
Fallopian tube damage or blockage. This condition usually results from inflammation of the fallopian tube (salpingitis). Chlamydia is the most frequent cause. Tubal inflammation may go unnoticed or cause pain and fever.
Tubal damage with scarring is the major risk factor of a pregnancy in which the fertilized egg is unable to make its way through the fallopian tube to implant in the uterus (ectopic pregnancy). One episode of tubal infection may cause fertility difficulties. The risk of ectopic pregnancy increases with each occurrence of tubal infection.
Endometriosis. Endometriosis occurs when the tissue that makes up the lining of the uterus grows outside of the uterus. This tissue most commonly is implanted on the ovaries or the lining of the abdomen near the uterus, fallopian tubes and ovaries. These implants respond to the hormonal cycle and grow, shed and bleed in sync with the lining of the uterus each month, which can lead to scarring and inflammation. Pelvic pain and infertility are common in women with endometriosis.
Infertility in endometriosis also may be due to:
Ovarian cysts (endometriomas). Ovarian cysts may indicate advanced endometriosis and often are associated with reduced fertility. Endometriomas can be treated with surgery.
Scar tissue. Endometriosis may cause rigid webs of scar tissue between the uterus, ovaries and fallopian tubes. This may prevent the transfer of the egg to the fallopian tube.
Ovulation disorders. About 25 percent of female infertility is caused by ovulation disorders. Disruption in the part of the brain that regulates ovulation (hypothalamic-pituitary axis) can cause deficiencies in luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Even slight irregularities in the hormone system can affect ovulation.
Specific causes of hypothalamic-pituitary disorders include:
- Direct injury to the hypothalamus or pituitary gland
- Pituitary tumors
- Excessive exercise
- anorexia nervosa
Elevated prolactin (hyperprolactinemia). The hormone prolactin stimulates breast milk production. High levels in women who aren't pregnant or nursing may affect ovulation. An elevation in prolactin levels may also indicate the presence of a pituitary tumor. Some drugs can elevate levels of prolactin. Milk flow not related to pregnancy or nursing (galactorrhea) can be a sign of high prolactin.
Polycystic ovary syndrome (PCOS). An increase in androgen hormone production causes PCOS. In women with increased body mass, elevated androgen production may come from stimulation by higher levels of insulin. In lean women, the elevated levels of androgen may be stimulated by a higher ratio of luteinizing hormone (LH). Lack of menstruation (amenorrhea) or infrequent menses (oligomenorrhea) are common symptoms in women with PCOS.
In PCOS, increased androgen production prevents the follicles of the ovaries from producing a mature egg. Small follicles that start to grow but can't mature to ovulation remain within the ovary. A persistent lack of ovulation may lead to mild enlargement of the ovaries.
Without ovulation, the hormone progesterone isn't produced and estrogen levels remain constant. Elevated levels of androgen may cause increased dark or thick hair on the chin, upper lip or lower abdomen as well as acne and oily skin.
Early menopause (premature ovarian failure). Early menopause is the absence of menstruation and the early depletion of ovarian follicles before age 35. Although the cause is often unknown, certain conditions are associated with early menopause, including:
Autoimmune disease. The body produces antibodies to attack its own tissue, in this case the ovary. This may be associated with hypothyroidism (too little thyroid hormone).
Radiation or chemotherapy for the treatment of cancer
Benign uterine fibroids. Fibroids are benign tumors in the wall of the uterus and are common in women in their 30s. Occasionally they may cause infertility by interfering with the contour of the uterine cavity, blocking the fallopian tubes.
Pelvic adhesions. Pelvic adhesions are bands of scar tissue that bind organs after pelvic infection, appendicitis, or abdominal or pelvic surgery. They may limit the functioning of the ovaries and fallopian tubes and impair fertility. Scar tissue formation inside the uterine cavity after a surgical procedure may result in a closed uterus and ceased menstruation (Asherman's syndrome). This is most common following surgery to control uterine bleeding after giving birth.
Other causes. A number of other causes can lead to infertility in women:
Medications. Temporary infertility may occur with the use of certain medications. In most cases, fertility is restored when the medication is stopped.
Thyroid problems. Disorders of the thyroid gland, either too much thyroid hormone (hyperthyroidism) or too little (hypothyroidism), can interrupt the menstrual cycle and cause infertility.
Cancer and its treatment. Certain cancers — particularly female reproductive cancers — often severely impair female fertility. Both radiation and chemotherapy may affect a woman's ability to reproduce. Chemotherapy may impair reproductive function and fertility more severely in men than in women.
Other medical conditions. Medical conditions associated with delayed puberty or amenorrhea, such as Cushing's disease, sickle cell disease, HIV/AIDS, kidney disease and diabetes, can affect female fertility.
Many of the risk factors for both male and female infertility are the same. These include:
Age. Age is the strongest predictor of female fertility. After about age 32, a woman's fertility potential declines. A woman does not renew her oocytes (eggs). There is no one special point when fertility declines — it's a gradual transition.
Chromosomal abnormalities. Infertility in older women may be due to a higher risk of chromosomal abnormalities that occur in the eggs as they age. Older women are also more likely to have health problems that may interfere with fertility. The risk of miscarriage also increases with a woman's age. A gradual decline in fertility is possible in men older than 35.
Tobacco smoking. Women who smoke tobacco may reduce their chances of becoming pregnant and the possible benefit of fertility treatment. Miscarriages are more frequent in women who smoke.
Alcohol. There's no certain level of safe alcohol use during conception or pregnancy.
Body mass. Extremes in body mass — either too high (body mass index, or BMI, of greater than 25.0) or too low (BMI of lower than 20.0) — may affect ovulation and increase the risk of infertility.
Being overweight. Among American women, infertility often is due to a sedentary lifestyle and being overweight.
Being underweight. Women at risk include those with eating disorders, such as anorexia nervosa or bulimia, and women on a very low-calorie or restrictive diet. Strict vegetarians also may experience infertility problems due to a lack of important nutrients such as vitamin B-12, zinc, iron and folic acid. Marathon runners, dancers and others who exercise very intensely are more prone to menstrual irregularities and infertility.
When to seek medical advice
In general, don't be concerned about infertility unless you and your partner have been trying to conceive regularly for at least one year. However, if you're a woman older than 30 or haven't had a menstrual flow for longer than six months, seek a medical evaluation. If you have a history of irregular or painful menstrual cycles, pelvic pain, endometriosis, pelvic inflammatory disease (PID) or repeated miscarriages, schedule a consultation with your doctor sooner. If you're a man with a low sperm count or a history of testicular, prostate or sexual problems, consider seeking help earlier.
Screening and diagnosis
If you and your partner are unable to achieve conception within a reasonable time and would like to do so, seek help. The woman's gynecologist, the man's urologist or your family physician can determine whether there's a problem that requires a specialist or clinic that treats infertility problems.
One-fourth of infertile couples have more than one cause of their infertility. Thus, your physician will usually begin a comprehensive infertility examination of both you and your partner.
Before undergoing infertility testing, be aware that a certain amount of commitment is required. Your physician or clinic will need to determine what your sexual habits are and may make recommendations about how you may need to change those habits. The tests and periods of trial and error may extend over several months.
Evaluation is expensive and in some cases involves operations and uncomfortable procedures, and the expenses may not be reimbursed by many medical plans. Finally, there's no guarantee, even after all testing and counseling, that conception will occur. However, for couples who are eager to have their own child, such an evaluation is best. It may result in a successful pregnancy.
Tests for men
For a man to be fertile, the testicles must produce enough healthy sperm, and the sperm must be ejaculated effectively into the woman's vagina. Tests for male infertility attempt to determine whether any of these processes are impaired.
The first step is a general physical examination. This includes examination of your genitals and questions concerning your medical history, illnesses and disabilities, medications, and sexual habits. Your doctor may ask for a specimen of ejaculated semen. This is generally obtained by masturbating or by interrupting intercourse and ejaculating your semen into a clean container. Your doctor will provide instructions. Such a specimen may be required more than once.
A laboratory analyzes your semen specimen for quantity, color and presence of infections or blood. Detailed analysis of the sperm also is done. The laboratory will determine the number of sperm present and any abnormalities in the shape and movement (motility) of the sperm. Often sperm counts fluctuate from one specimen to the next.
Other tests are sometimes required of the man. A blood test to determine the level of testosterone and other hormones is common.
Tests for women
For a woman to be fertile, the ovaries must release healthy eggs regularly, and her reproductive tract must allow the eggs and sperm to pass into her fallopian tubes for a possible union. Her reproductive organs must be healthy and functional.
After your doctor asks questions regarding your health history, menstrual cycle and sexual habits, a general physical examination is done. This includes a regular gynecologic examination. Specific fertility tests may include:
Confirmation of ovulation. A blood test is sometimes performed to determine the levels of hormones involved in successful ovulation.
Hysterosalpingography. This test evaluates the condition of your uterus and fallopian tubes. Fluid is injected into your uterus, and an X-ray is taken to determine whether the fluid progresses out of the uterus and into your fallopian tubes and general peritoneal cavity. Blockage or problems often can be located and may be corrected with medication or surgery.
Laparoscopy. Performed under general anesthesia, this procedure involves inserting a thin viewing device into your abdomen and pelvis to examine your fallopian tubes, ovaries and uterus. A small incision (8 to 10 millimeters) is made beneath your navel, and a needle is inserted into your abdominal cavity. A small amount of gas (usually carbon dioxide) is inserted into the abdomen to create space for entry of the laparoscope — an illuminated, fiber-optic telescope.
The most common problems identified by laparoscopy are endometriosis and scarring. Your doctor can also detect blockages or irregularities of the fallopian tubes and uterus. Often a blue dye is injected into the cervical canal and through the uterus and fallopian tubes to determine whether they are open. At the end of the procedure, the gas and laparoscope are drawn out and the incision is closed. Laparoscopy generally is done on an outpatient basis.
Basal body temperature. Although this test was once a standard, basal body temperature charting is used less often today. Charting a woman's body temperature doesn't give as precise time of ovulation as earlier believed.
Urinary luteinizing hormone (LH) detector kits. A number of at-home kits are available to test your LH level. Although these kits may be helpful, they also can be inaccurate and misleading. Consult your doctor before using one.
Not everyone needs to undergo all, or even many, of these tests before the cause of infertility is found. Which tests are used and their sequence depend on discussion and agreement between you and your doctor.
In about one-fifth of infertile couples, no specific cause is found (unexplained infertility). Couples receiving the diagnosis of unexplained infertility are more likely to seek multiple health care providers and be influenced by the experiences of family and friends or literature that promises new hope. Although infertility is unexplained, the pregnancy rate for these couples is among the highest.
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