Most cases of male infertility cases are due to low sperm counts, poor sperm quality, or both.
Sperm abnormalities are a critical factor in male infertility. These abnormalities include:
Risk factors for male infertility include:
In addition to a medical history and physical exam, specific tests for male infertility may include:
Treatment for male infertility should first address any underlying medical conditions that may be contributing to fertility problems. Drug therapy may be used to treat hormonal disorders or infections. Surgery may be used to repair varicoceles in some men and correct any obstructions in the reproductive tract.
If fertility issues remain unresolved, intracytoplasmic sperm injection (ICSI) is commonly used in combination with in vitro fertilization (IVF) to achieve pregnancy when male infertility is a factor. ICSI involves injecting a single sperm into an egg obtained through IVF. The fertilized egg is then implanted back into the woman. Pregnancy success rates depend on many different factors.
The American Society For Reproductive Medicine recommends:
Infertility is the failure of a couple to become pregnant after 1 year of regular, unprotected intercourse. About a third of infertility problems are due to male infertility, and another third are due to female infertility. In the remaining cases, infertility affects both partners or the cause is unclear.
Male infertility is due to problems with sperm.
The male reproductive system creates sperm that is manufactured in the seminiferous tubules within each testicle. The sperm have to reach the uterus and the fallopian tube in order to fertilize a woman's egg.
The male reproductive system includes the testicles, epididymis, vas deferens, seminal vesicles, prostate gland, urethra, and penis.
Sperm are male reproductive cells. They are produced in the two testicles (testes). The testes are contained in the scrotal sac (scrotum).
Structure of Sperm
A mature sperm cell has 3 parts:
Sperm production depends on 3 major hormones:
FSH and LH are produced in the brain's pituitary gland. These hormones are also important for female reproduction. Testosterone is produced in the testicles.
The scientific word for sperm development is spermatogenesis. This process begins in the testicles (testicles):
When a man experiences sexual excitement, his penis fills with blood and becomes erect. Nerves stimulate muscle contractions, which force the sperm out from the epididymis (where they are produced) through the penis' urethra (where they are expelled):
Most cases of male infertility cases are due to low sperm counts, poor sperm quality, or both. The remaining cases of male infertility are caused by a variety of factors including anatomical problems, hormonal imbalances, and genetic defects.
Sperm abnormalities can be caused by many factors. They include congenital birth defects, disease, chemical exposure, and lifestyle habits. In many cases, the causes of sperm abnormalities are unknown.
Sperm abnormalities are categorized by whether they affect sperm count, sperm movement, or sperm shape:
Retrograde ejaculation occurs when the muscles of the bladder wall do not function properly during orgasm and sperm are forced backward into the bladder instead of forward out of the urethra. Sperm quality is often impaired.
Retrograde ejaculation can result from several conditions:
Any anatomical abnormalities that damage or block the testes, tubes, or other reproductive structures can affect sperm and reduce fertility. These conditions are often birth defects such as:
Any condition that affects the production of the hormones testosterone, follicle stimulating hormone (FSH), or luteinizing hormone (LH) can affect sperm production:
Sometimes a man's immune system mistakenly identifies sperm as a foreign invader and produces antibodies that attack and destroy the sperm. Antisperm antibodies may result from surgery, infections, or trauma or twisting of the testicles.
Certain inherited disorders can impair fertility. Examples include:
There is continued research into genetic causes or risk factors for male infertility. However, genetic testing as part of an evaluation appears to be in the research stages at this time.
A varicocele is an abnormally enlarged and twisted (varicose) vein in the spermatic cord that connects to the testicle. Varicoceles are found more often in men who report infertility problems. However, most men with a variocele are fertile. It is not clear how much they affect fertility or by what mechanisms. They can raise testicular temperature, which may have effects on sperm production, movement, and shape.
Age-related sperm changes in men are not abrupt, but are a gradual process. Aging can adversely affect sperm counts and sperm motility (the sperm's ability to swim quickly and move in a straight line). The genetic quality of sperm declines as a man ages.
Medical conditions that can affect male fertility include:
A number of lifestyle factors may affect sperm and contribute to infertility. They include:
Occupational or other long-term exposure to certain types of toxins and chemicals (such as herbicides and pesticides) may reduce sperm count by either affecting testicular function or altering hormone systems. Estrogen-like and hormone-disrupting chemicals such as bisphenol A, phthalates, and organochlorines are particular concerns.
Chronic exposure to heavy metals such as lead, cadmium, or arsenic may affect sperm quality. These chemicals usually affect men who have long-term and intense occupational exposure to them.
Health care providers recommend that both male and female partners get tested for infertility if pregnancy fails to occur after 1 year of regular unprotected sexual intercourse. Fertility testing should be done earlier if a woman is over age 35 or if either partner has known risk factors for infertility.
Because male infertility can be due to many different conditions, a number of tests are used for diagnosis. Your provider may refer you to a fertility specialist, usually an urologist, for specific tests.
The provider will ask about any medical or sexual factors that might affect fertility, such as:
The provider will carefully examine the scrotum and testicles. Varicoceles can be felt during examination of the scrotum. (They are described as feeling like "a bag of worms.") The doctor will also check the prostate gland. The provider will examine the penis for any signs of infection or anatomical abnormalities.
The basic test to evaluate a man's fertility is a semen analysis. The sperm collection involves the following steps:
The sperm count test is performed if a man's fertility is in question. It is helpful in determining if there is a problem in sperm production or quality of the sperm as a cause of infertility. The test may also be used after a vasectomy to make sure there are no sperm in the semen.
A semen analysis will provide information on:
Semen Volume: The amount of semen is important. Most men ejaculate between 2.5 to 5 milliliters (1/2 to 1 teaspoon) of semen. Either significantly high or low amounts can indicate problems. Low amounts are a sign of fewer sperm. High amounts may dilute the concentration of sperm.
Semen Concentration: Concentration refers to the amount of sperm found in 1 milliliter of semen. A normal concentration is at least 15 million sperm per milliliter.
Sperm Count: Sperm count refers to the number of sperm found in the entire sample of semen. In general, a normal sperm count is considered to be 20 million per milliliter of semen.
Sperm Viability: At least 50% of the sperm in the semen sample should be alive (viable).
Sperm Motility: Motility (the speed and quality of movement) is graded on a scale from 0 (worst) to 4 (best). Grades 3 and 4 indicate good mobility. At least 50% of the sperm should be motile.
Sperm Morphology: Morphology is the size, shape, and structure of the sperm. At least 50% of the sperm should be of normal appearance.
Other Factors: The acidity of the semen is tested. The lab will test for presence or absence of certain chemicals and enzymes, such as fructose. The semen will be tested for how thick it is and how quickly it liquefies, and whether it clumps together.
Other Sperm Tests: Although less commonly performed, sperm penetration tests may be used to evaluate function. For example, the sperm penetration assay measure the sperm's ability to penetrate specially prepared hamster eggs. The exact role for these tests for most patients with infertility remains unclear.
Blood tests may be used to check for hormone levels of testosterone, follicle stimulating hormone (FSH), and luteinizing hormone (LH). A blood test can also check for evidence of sexually transmitted infections.
A post-ejaculatory urine sample can detect presence of sperm, which may indicate retrograde ejaculation.
Ultrasound uses sound waves to produce an image. Ultrasound imaging may be used to check for abnormalities or blockages in the testicles, or to find varicoceles that are too small for physical detection.
In transrectal ultrasound, a probe is inserted into the rectum to provide images of the prostate gland, vas deferens, and seminal vesicles.
A small tissue sample of the testicle may be taken using a thin needle. A biopsy may be performed for diagnostic purposes to evaluate sperm production function. A biopsy may also be used to collect sperm that will be used in an intracytoplasmic sperm injection (ICSI) fertility procedure.
Genetic testing may be recommended for some men, particularly those who will use ICSI. Genetic testing can help identify sperm DNA fragmentation, chromosomal defects, or the possibility of genetic diseases that can be passed on to children.
Treatment for male infertility depends on the cause of infertility, and whether a cause is found. Treatments may include:
Antioxidants are man-made or natural substances that may prevent or delay some types of cell damage. There is some thought that these agents may improve sperm function and therefore fertility.
Endocrine treatments may be tried in selected men with identified endocrine dysfunction as a possible cause. The goal with these treatments is to increase the level of testosterone within the testes. These include:
Conditions for treating a varicocele that can be felt on physical exam include both of the following:
Depending on semen analysis findings, other fertility treatments such as intrauterine insemination, in vitro fertilization (IVF), or intracytoplasmic sperm injection (ICSI) are other options before surgical treatment of the varicocele.
Invasive treatment options include:
In general, surgical invasive treatment of varicoceles has been found to increase sperm counts by around 12 million and improve sperm motility by around 10 to 11%. These improvements take 3 to 6 months to be evident.
Studies that report on pregnancy rates after treatment appeared to indicate an improvement for couples with otherwise unexplained infertility. The quality of these studies is generally not considered to be high.
IUI, ICSI, and other assisted reproductive technologies (ART) are offered by fertility clinics. ICSI is used in combination with in vitro fertilization (IVF). Choosing a good fertility clinic is important. Fertility procedures are expensive and often not covered by insurance.
You and your partner should ask the fertility clinic questions about:
Adolescents and adult men undergoing cancer treatments who may want to father children in the future should consider banking and freezing their sperm for later use in assisted reproductive therapies. This technique is called sperm cryopreservation.
Sperm cryopreservation is recommended by the American Society of Clinical Oncology as the method with the highest likelihood of success for male cancer survivors. It can be easily done and will not delay cancer treatment.
These banking methods are not appropriate for pre-adolescent boys being treated for childhood cancers such as leukemia. Researchers are investigating ways that stem cell transplantation may someday help these children regain their fertility while avoiding leukemia relapse.
Assisted reproductive technologies (ART) are medical techniques that help couples conceive. These procedures involve either:
Fertilization may occur either in the laboratory or in the uterus. In the United States, the number of live birth deliveries from ART has doubled in the last decade. About 50,000 live births (deliveries of one or more infants) occur each year using assisted reproductive technologies. According to the Centers for Disease Control (CDC), over 1% of all babies born in the United States every year are conceived using ART.
Technically, the term ART refers only to fertility treatments, such as in vitro fertilization (IVF) and its variants, which handle both egg and sperm. Therefore intrauterine insemination (IUI), or artificial insemination, is not officially considered a form of ART.
Before fertilization using IUI or ICSI can take place, the sperm must be collected and prepared.
When a man has no available sperm in the ejaculate (usually from blockage, vasectomy, or lack of vas deferens), the sperm must be retrieved from the testes or the epididymis.
Various microsurgical techniques are used for retrieval. The procedure may be done under local or general anesthesia, using a spring-loaded biopsy device, a thin needle, incisions, or microsurgical techniques. Most procedures can be done on an outpatient basis, and the man returns home the same day.
Sperm washing is done to prepare the sperm for use in ART procedures. Sperm washing can help remove chemicals (prostaglandins) that can cause the woman's uterus to contract and cramp. Sperm washing can also help remove sexually transmitted viruses, such as HIV and hepatitis, which could potentially be transmitted to the woman during fertility treatment.
There are 3 basic methods for sperm washing:
Sperm can be fresh or it can be frozen in advance. Men who have no sperm count not caused by obstruction (nonobstructive azoospermia) often use frozen sperm. Sperm that will be frozen is retrieved using a testicular biopsy. Evidence indicates that both fresh and frozen sperm work equally well for fertilization outcomes.
Artificial insemination (AI) is the least complex of fertility procedures and is often tried first in uncomplicated cases of infertility. AI involves placing the sperm directly in the cervix (called intracervical insemination) or into the uterus (called intrauterine insemination, or IUI). IUI is the standard AI procedure.
IUI may be used under the following circumstances:
The IUI procedure is as follows:
The administration of fertility drugs and sperm retrieval is timed so that the process can coincide with time of ovulation.
If a woman fails to conceive after IUI, she may be a candidate for IVF.
Intracytoplasmic sperm injection (ICSI) is an ART used for couples when male infertility is the main factor. It is used in combination with IVF. It involves injecting a single sperm into an egg obtained from IVF.
In the ICSI procedure:
The greatest concern with this procedure has been whether it increases the risk for birth defects. Many, but not all, studies have reported no higher risks of birth defects in children born using ICSI procedures. However, if the father's infertility was due to genetic issues, this genetic defect may be passed on to male children conceived through ICSI.
Because several embryos are implanted to increase the chances for pregnancy success, multiple births can occur with IVF/ICSI. Multiple pregnancies increase the risks for a mother and her babies. In particular, there is increased risk for premature delivery and low birth weight.
IVF/ICSI can also pose specific risks for the woman. These risks include ovarian hyperstimulation syndrome, a condition induced by the fertility drugs used in the procedure. Ovarian hyperstimulation can result in dangerous fluid and electrolyte imbalances as well as increased blood pressure and higher risk for blood clots.
Another concern has been whether the ICSI procedure is overused. Some health care providers recommend ICSI for women who have failed prior IVF attempts or who have few or poor-quality eggs, even if their male partners have normal semen measurements. According to the Society for Assisted Reproductive Technology, there is little evidence that ICSI helps improve pregnancy success for couples who do not have a problem with male factor infertility.
Success Rates: Not all IVF/ICSI cycles result in pregnancy, and not all IVF-achieved pregnancies result in live births. When the woman's own eggs are used, results are better with fresh embryos than frozen embryos. Success rates provided by fertility clinics are not always a reliable indicator as they depend on many variables, including the age of the patients. The chances for success are best for women younger than age 37.
The Fertile Window
Couples can optimize their chances for conception by planning sexual intercourse during the woman's fertile window:
Frequency of Intercourse
Evidence indicates that chances are best for conception when sexual intercourse occurs every 1 to 2 days, especially during the fertile window. Less frequent regular sexual intercourse (2 to 3 times a week) also achieves good results. However, couples need to make their own personal choices about what amount of sexual activity is appropriate, comfortable, and desirable. Data suggest that abstinence (not having sex) for more than 5 to 10 days may adversely affect sperm health.
There is no evidence that any particular sexual positions, or resting after sex, help increase the chances for pregnancy. There is also no evidence that whether or not a woman achieves orgasm affects the likelihood of her becoming pregnant. Couples should be aware that water-based sexual lubricants (Astroglide, KY Jelly, saliva) can damage sperm's ability to swim and should not be used. For lubrication, try mineral oil, canola oil, or commercially available "fertility friendly" products such as Pre-Seed, which do not harm sperm.
Fertility and Seasonal Changes
Some studies have reported higher sperm counts and better motility in the winter than in the summer.
Everyone should eat a healthy diet rich in fresh fruits, vegetables, and whole grains. Replace animal fats with monounsaturated oils, such as olive oil. Certain specific nutrients and vitamins have been studied for their effects on male infertility and sperm health. They include antioxidant vitamins (vitamin C, vitamin E) and the dietary supplements L-carnitine and L-acetylcarnitine. To date, there is no conclusive evidence that they are effective.
Other tips for helping fertility include:
The fertility treatment process presents a roller coaster of emotions. There are almost no sure ways to predict which couples will eventually conceive. Some couples with multiple problems will overcome great odds, while other, seemingly fertile, couples fail to conceive. Many of the new treatments are remarkable, but a live birth is never guaranteed. The emotional burden on the couple is considerable, and some planning is helpful:
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Last reviewed on: 3/28/2016
Reviewed by: Scott Miller, MD, urologist in private practice in Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.