What causes male infertility?
The main causes of male infertility can be divided into the following categories:
- Sperm disorders. Problems with the production and maturation of sperm are the most common causes of male infertility. Sperm may be immature, abnormally shaped or unable to move properly. Or normal sperm may be produced in abnormally low numbers (oligospermia) or seemingly not at all (azoospermia). Sperm disorders may be caused by many different conditions, including the following:
- infectious diseases or inflammatory conditions, such as the mumps virus
- endocrine or hormonal disorders, such as Kallmann syndrome (an absence of or decrease in the function of the male testes) or a pituitary problem
- immunological disorders in which some men produce antibodies to their own sperm
- environmental and lifestyle factors
- genetic diseases, most of which are either directly or indirectly associated with sperm abnormalities, including:
- Cystic Fibrosis is an inherited condition that typically involves the lungs and pancreas, but that can also present as a cause of infertility with or without mild sinus problems. Most men who have cystic fibrosis have obstructive azoospermia because they were born without a vas deferens. This results in male infertility.
- Noonan syndrome is an inherited condition that can occur in either males or females. In males, this syndrome can cause abnormal gonadal (testicular) function.
- Myotonic dystrophy is an inherited condition with progressive multisystem involvement that results in infertility (underdeveloped testes and abnormal sperm production) in some cases.
- Hemochromatosis is an inherited condition that affects iron storage. Eighty percent of men with hemochromatosis have testicular dysfunction.
- Sickle cell disease is an inherited condition that affects the normal production of hemoglobin.
- Sex reversal syndrome is a condition in which a male has the sex chromosomes of a genetic female (XX, instead of XY), which results in azoospermia and other characteristics.
- Androgen receptor gene mutations is an inherited condition in which a man is genetically male (46,XY), but has infertility due to a defect in receptors for testosterone.
- Chromosomal abnormalities can lead to infertility. Men with an extra X sex chromosome, a condition known as Klinefelter syndrome, often do not produce sperm or produce very low quantities of sperm.
- Chromosome rearrangements can cause infertility. In some persons, there is a usual number of chromosomes (46) in the nucleus of cells, but rearrangements in the chromosome material, in which a piece of a chromosome has exchanged places with another, has occurred. Men with either azoospermia or oligospermia have a higher frequency of chromosome rearrangements than is found in the general population.
- Deletions in the Y chromosome can cause infertility. In some persons, there are the usual number of chromosomes (46) in the body cells, but small sections of the Y chromosome are missing or deleted. A small percentage of men with either azoospermia or oligospermia have deletions in the Y chromosome. It is important to understand that men who have genetic problems that cause their infertility, such as a deletion in the Y chromosome, can pass this problem to their sons if they elect to use their own sperm to achieve a pregnancy.
- Anatomical abnormalities can cause infertility. Obstructions of the genital tract can cause infertility by partially or totally blocking the flow of seminal fluid. Some of these abnormalities may be congenital (present at birth) or the result of a genetic defect. Others could have occurred due to infection or inflammation of the urogenital tract, surgery that left scar tissue in the genital tract, or the presence of varicose veins in the scrotum (scrotal varicoceles).
- Immotile cilia syndrome is a condition in which the sperm count is normal, but the spermatozoa are nonmotile, such as in Kartagener's syndrome, an inherited disorder.
- Mitochondrial deletions can cause infertility. Mitochondria are structures in the cell responsible for energy production. There is actually a set of genes in the mitochondria, separate from the normal chromosome set contained in the nucleus. Recently, it has been discovered that these genes, when altered or deleted, can affect a person's health and/or fertility.
- Liver disease, renal disease, or treatment for seizure disorders
Infertility Treatment for Men
There is a range of treatment options currently available for male factor infertility. Treatment may include:
- Assisted reproductive technologies (ART). ART may include the following:
- Artificial insemination. Artificial insemination involves the placement of relatively large numbers of healthy sperm either at the entrance of the cervix or into the partner's uterus, bypassing the cervix, to have direct access to the fallopian tubes.
- IVF, GIFT, and other techniques. In vitro fertilization (IVF) or gamete intra-fallopian transfer (GIFT) have been used for the treatment of male infertility. As is the case with artificial insemination, IVF and similar techniques offer the opportunity to prepare sperm in vitro so oocytes are exposed to an optimal concentration of high quality, motile sperm.
- Microsurgical fertilization (microinjection techniques, such as intracytoplasmic sperm injection, or ICSI). This treatment is used to facilitate sperm penetration by injection of a single sperm into the oocyte. Fertilization then takes place under the microscope.
- Drug therapy. A small percentage of infertile men have a hormonal disorder that can be treated with hormone therapy. Hormonal imbalances caused by a dysfunction in the mechanism of interaction between the hypothalamus, the pituitary gland, and the testes directly affect the development of sperm (spermatogenesis). Drug therapy may include gonadotropin therapy, antibiotics or another medication if deemed appropriate.
- Surgery. Surgical therapy in male infertility is designed to overcome anatomical barriers that impede sperm production and maturation or ejaculation. Surgical procedures to remove varicose veins in the scrotum (varicocele) can sometimes serve to improve the quality of sperm.
What is unexplained infertility?
About 5 to 10 percent of couples have unexplained infertility, for which a cause, despite all investigations, is not found. Unexplained infertility does not mean there is no reason for the problem, but that the reason cannot be identified at the present time.
If you suspect you are experiencing infertility, seek medical consultation early. The age of the woman and the duration of the couple's infertility may influence the success of treatment.