- Abnormal sperm parameters
- Antisperm antibodies
Abnormal Sperm Parameters
Abnormalities in the semen are primarily due to a defect in sperm production by the testicles. Spermatozoa (sperm) are relatively fragile cells and are easily damaged by a number of environmental and life style habits. Increased body temperature resulting from illness, prolonged periods of sitting in hot tubs, or tight clothing can affect sperm production and function. Strenuous repetitive exercise, such as long distance bicycling or marathon running, can also alter sperm production, as can significant weight loss or gain. Drugs, including alcohol and nicotine, can decrease male fertility and should be minimized or avoided while attempting to achieve pregnancy.
Many genetic diseases can impair male fertility, including Klinefelter’s syndrome and cystic fibrosis. Exposure to environmental toxins, such as heavy metals and other chemicals, can also reduce male fertility.
Infections with microorganisms, such as chlamydia, mycoplasma, or niesseria gonorrhea, also can decrease fertility and are effectively treated with antibiotics. Rarely, a male will produce antibodies to his own sperm. When this occurs, his immune system mistakes his sperm for an invading pathogen and seeks to destroy them.
Hormonal imbalances, such as hypogonadotropic hypogonadism, can lead to male infertility. In this rare condition, gonadotropin releasing hormone ( GnRH ) , which is released from the hypothalamus, is deficient. GnRH controls the process leading to the production of testosterone and other reproductive hormones. Diseases of the pituitary gland also can lead to deficiencies of FSH and LH, which are hormones necessary for sperm production.
A varicocele, an enlargement of the veins to the testes (spermatic cord), may be present. The varicocele impairs the blood flow needed to cool the testicles, thus raising the temperature of the involved testicle. A varicocele may be accompanied by pain and often can be treated surgically by a urologist.
Retrograde ejaculation occurs when sperm are propelled “backwards” into the bladder rather than ejaculated through the penis. This condition can be caused by certain medications, previous surgery, spinal cord disease, diabetes, and other factors. Sometimes, it can be treated by removing the causative medication or by surgery.
The absence of sperm in the ejaculate (azoospermia) may be due to an obstruction at the level of the vas deferens, epididymis, or even at the level of the testes. It may also be due to a bilateral congenital absence of the vas. Some men might have testicular failure, i.e. failure of production of sperm. This may be the result of a chromosomal disorder or previous infections such as the mumps. It may also be associated with the history of undescended testes.
Some instances of male infertility can be attributed to anti-sperm antibodies. This is an immunological response whereby the male’s body attacks the sperm, impeding fertility in a variety of ways. The antibodies may prevent the sperm from being able to properly travel through a woman’s cervical mucus, impair the sperm from fusing to the egg, and/or inhibit the sperms ability to penetrate the egg. Some men are more at risk of developing antibodies than others.
These may occur following reversal of a vasectomy or other surgery on the male genitals and may also be related to previous infections or injury.