Infertility
Introduction
You and your partner have tried for months, perhaps for even more than a year. But despite sexual intercourse without birth control, you've been unable to conceive a child.
If you've been trying to conceive for more than a year, there's a good chance that something may be interfering with your efforts to have a child. 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.
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.
Causes
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. 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.
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 during 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 a sperm to reach an 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 or causes of infertility can involve one or both partners. For many couples having problems with fertility, the male partner is either the sole or a contributing cause. Problems with female fertility are common as well, but present less often than those in the male partner. In both men and women, multiple factors can account for difficulty with fertility. 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.
Causes of male infertility
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. Most cases of male infertility 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 are 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 very few infertile men.
- Low sperm concentration. A normal sperm concentration is greater than or equal to 20 million sperm per milliliter of semen. A count of 10 million or fewer sperm per milliliter of semen indicates low sperm concentration (subfertility). A count of 40 million sperm or higher per milliliter of semen indicates increased 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 internal body temperature compared to the temperature in the scrotum, 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.
Impaired delivery of sperm. Problems with the delivery of sperm from the penis into the vagina can cause infertility.
Causes of female infertility
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
Treatment
Treatment of infertility depends on the cause, the duration of the problem, the age of the partners and their specific wishes. Some causes of infertility can't be corrected. However, various means of insemination or embryo transfer may be possible so that a woman can still become pregnant.
Nonsurgical fertility treatment falls into two main categories:
- Restoring or bringing about fertility
- Assisted reproductive technology (ART)
These approaches can involve steps related to the male or to the female, or both. Sperm survive in the female reproductive tract for up to 72 hours, and an egg can be fertilized for up to 24 hours after ovulation. Increasing the frequency of intercourse increases the chances for conception.
Other approaches that involve the male include:
- Treatment of general sexual problems. Addressing impotence or premature ejaculation can improve fertility. Treatment for these problems often is with medication or behavioral approaches.
- Addressing lack of sperm. When the source of infertility lies in the man's sperm, or lack of it, restoring or initiating fertility is sometimes possible. For example, in some instances, surgical correction of a varicocele will restore fertility. Problems with the testicles, prostate gland, seminal vesicle and urethra also can be treated. When sperm production is impaired because of damage to the sperm-producing areas of the testicle, drug treatment has little benefit. In rare instances when sperm production is impaired because of a pituitary problem, treatment with pituitary hormones called gonadotropins may help. When infection hampers sperm production, both you and your partner will need treatment.
Most types of male infertility aren't preventable. However, avoid drug and tobacco use and excessive alcohol consumption, which may contribute to male infertility. Also, high temperatures can affect sperm production and motility. Although this effect is usually temporary, avoid hot tubs and steam baths.
If you're a man who's uncertain about whether you would eventually like to become a father, don't undergo permanent sterilization, such as a vasectomy. Although surgery to reverse this condition is possible, risks are involved that could affect fertility in other ways.
A woman can increase her chances of becoming pregnant in a number of ways:
- Exercise moderately. Regular exercise is important, but if you're exercising so intensely that your periods are infrequent or absent, your fertility is likely to be impaired.
- Avoid weight extremes. Being overweight or underweight can affect your hormone production and cause infertility.
- Avoid alcohol, tobacco and street drugs. These substances may impair your ability to conceive or produce a healthy child. Don't drink alcohol or smoke tobacco. Avoid illegal drugs such as marijuana and cocaine.
- Limit medications. The use of both prescription and nonprescription drugs can decrease your chance of getting pregnant or keeping a pregnancy. Talk with your doctor about any medications you take regularly.
Informations obtained from National Institute of Health.