If getting pregnant has been a challenge for you and your partner, you’re not alone. Ten percent to 15 percent of couples in the United States are infertile. Infertility is defined as not being able to get pregnant despite having frequent, unprotected sex for at least a year.
If you’ve been trying to conceive for more than a year, there’s a chance that something may be interfering with your efforts to have a child. 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.
What is Infertility?
Most experts define infertility as not being able to get pregnant after at least one year of trying. Women who are able to get pregnant but then have repeat miscarriages are also said to be infertile.
- Pregnancy is the result of a complex chain of events. In order to get pregnant:
- A woman must release an egg from one of her ovaries (ovulation).
- The egg must go through a fallopian tube toward the uterus (womb).
- A man’s sperm must join with (fertilize) the egg along the way.
- The fertilized egg must attach to the inside of the uterus (implantation).
- Infertility can result from problems that interfere with any of these steps
Is Infertility a Common Problem?
About 12 percent of women (7.3 million) in the United States aged 15-44 had difficulty getting pregnant or carrying a baby to term in 2002, according to the National Center for Health Statistics of the Centers for Disease Control and Prevention.
Is Infertility Just a Woman’s Problem?
No, infertility is not always a woman’s problem. In only about one-third of cases is infertility due to the woman (female factors). In another one third of cases, infertility is due to the man (male factors). The remaining cases are caused by a mixture of male and female factors or by unknown factors.
Over the past twenty years, fertility problems have increased dramatically. At least 25 percent of couples planning a baby will have trouble conceiving, and more and more couples are turning to fertility treatments to help them have a family.
What is the cause? From a medical point of view, infertility is believed to be caused by the following factors, and in these proportions.
Causes of 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.
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 psychological 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. And some men who seek treatment for infertility lack the tubes that carry sperm (vasa deferentia).
- 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.
- Anti-sperm 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 vasa deferentia.
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.
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 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.
Some cases of female infertility are 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. In addition, 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.
- Tobacco smoking.
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 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.
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 a woman’s fertility.
Many of the risk factors for both male and female infertility are the same. They include:
- Age. Age is the strongest predictor of female fertility. After about age 32, a woman’s fertility potential gradually declines. A woman does not renew her oocytes (eggs). 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 following 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.
Most pregnancies occur during the first six cycles of intercourse in the fertile phase. Overall, after 12 months of unprotected intercourse, approximately 85 percent of couples will become pregnant. Over the next 36 months, about 50 percent of the remaining couples will go on to conceive spontaneously.
Conditions Affecting Both Partners
A number of factors that affect males and females alike can increase the risk of infertility. Perhaps the most common problem is age the older a person is, the more difficult it is to become pregnant. Over the last 20 to 30 years there has been a trend to delay childbearing, often until women are in their 30s. A woman reaches her peak fertility at age 18 or 19, with little change until the mid-20s. As she approaches age 30, her hormone levels start to decline and her fertility also begins a slow decline, with a more rapid decline after age 35. Menopause, which occurs in the late 40s to early 50s in most women, marks the end of a woman’s natural ability to bear children. A man’s fertility decline is not as rapid and has no clear-cut end point, but a man of 50 has lower hormone levels and is likely less fertile than he was at age 25 or 30
What Are Infertility, Sub fertility, and Sterility?
Doctors use these and other terms to define different types of fertility-related conditions. Even so, the definitions of the above terms have changed as technology has advanced.
Sterility is the absolute inability to procreate. For instance, a woman has no uterus or a man has no testes (the male sex organs). In years past, a woman with blocked fallopian tubes or a man with an obstructed vas deferens would be considered sterile and beyond help. With the advent of assisted reproductive technology (ART), however, this is no longer the case. Many couples who were once in this category can now get help.
Infertility is usually defined as the inability to achieve pregnancy after one year of frequent, unprotected intercourse. This is not an exact measurement. Over time many couples in this category may, in fact, achieve pregnancy. Statisically, after five years, nearly one half of so-called “infertile” couples do conceive.
Subfertility is used to describe the gray area between normal fertility and sterility; the term is often used interchangeably with infertility.
Fecundability, from “fecunditas,” the Latin word for fertility, is the average pregnancy rate after one menstrual cycle. The normal rate in humans is 20%. Seventy-five percent of normally fertile couples are expected to have conceived in six months, and almost 100% by one year.
Normal fertility can be considered from the point of view of the couple, the female, or the male. We are going to look at male fertility its biological steps and mechanisms, defects, the causes of those defects and what can be done to remedy them.
Normal Male Fertility
As male factors have been increasingly implicated as a major cause of infertility, investigators have focused on the underlying physical processes in men. If the sperm count is low, then why? Or, if the sperm count is normal, why do the sperm not fertilize?
That there are literally dozens of factors leading to a completely normal spermatozoon, the form of sperm that is present in semen. These involve the structure of the testis; the hormones that influence its function; the receptors for these hormones; the maturation process through which the germ cell develops into a spermatozoon; the composition of the seminal plasma; and all the enzymes, receptors, and reactions that make the sperm capable of fertilizing the egg. In these steps, there are dozens of occasions for mistakes and problems.
Normal Female Fertility
Knowing your own body and being able to tell when you are fertile or ovulating is an important skill that every woman should have. You will save yourself an enormous amount of worry and anxiety when you get to know your body and can control your risk of unwanted pregnancy.
The fact is that there are only certain times during your menstrual cycle when you are fertile or can get pregnant in. So it pays off to know when those times are.
Your body will give you clear clues and signals as to when fertility is approaching and happening.
A woman is fertile when she is ovulating and for a few days before ovulation when fertile cervical mucus is present.
Ovulation usually occurs mid cycle. More precisely, ovulation usually occurs 14 days before the onset of bleeding.
Not at day 14 of the menstrual cycle as is commonly believed.
However – ovulation can be upset and delayed by many factors, eg, sickness, alcohol, travel, stress etc which is why simply counting the days can be inaccurate.
You will find your success in tracking your fertility will be far greater when you become adept at recognizing your own personal fertility signals rather than just counting the days.
Ovulation can also spontaneously occur during your natal lunar phase. Your natal lunar (moon) phase fertile time can occur at any time during your menstrual cycle, including before, during and after your period.
Your natal lunar fertile time is individual to you and is calculated from your birth data – it is all to do with which phase of the moon you were born under.