Successful human reproduction normally requires the maturation and release (ejaculation) of sperm from the testes.
The process that results in the release of mature sperm is complex, can be disrupted by several disorders, and involves many
different components. The known reasons for an abnormal semen analysis and poor sperm quality may become understood once you learn
this material. Alternatively, you can focus more specifically on problems that your physician has addressed with you about the sperm.
In this sperm tutorial, a large amount of information about the production and release of sperm is presented by
Dr. Eric Daiter.
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for additional information.
Many of the normal events that result in mature sperm production and release are currently understood. Dr. Daiter
reviews these events, including the movement of the testes from the male abdomen to the scrotum prior to birth, the different types
of cells that are found in a normal testis and their important and unique functions, the maturation process from an immature sperm
cell to a highly specialized mature sperm cell, the modifications in a sperm cell's shape and motility during its storage in the
epididymis, the physiologic mechanism that allows for the release of the mature sperm, and the final changes to the sperm hours
after release that allow it to fertilize an egg.
The detection of normal sperm is limited since the semen analysis is basically a sperm and semen "appearance test"
and there are no reliable sperm function tests. Dr. Daiter discusses the benefits and limitations of the semen analysis, the way in
which a semen analysis is performed, and the reliability (positive and negative predictive values) of the various sperm function tests
that are currently available.
There are several different possible causes for abnormal sperm and semen, each with their own treatment
alternatives. Dr. Daiter categorizes and reviews these causes, including varicoceles (the dilatation of the testicular veins
within the spermatic cord that is found in up to 15% of all healthy fertile men), antisperm antibodies (the types of antibodies,
their detection, and their clinical significance for fertility), testicular causes (including exposure to excessive heat, testicular
surgery, infections, radiation, trauma, substance abuse, testicular cancer, toxins, medications, chromosomal abnormalities and DES
exposure in utero), pituitary causes (including pituitary tumors, elevated blood prolactin concentrations, pituitary damage, thyroid
disease and hemochromatosis), and hypothalamic and central nervous system causes (structural lesions, Kallman's syndrome, and
The clinical evaluation of abnormal sperm or semen and the evaluation of a complete absence of sperm in semen
(azoospermia) should involve several components. Dr. Daiter presents his usual evaluation, including a detailed fertility history,
a detailed medical history, an expert physical examination (usually by a Urologist), and the initial laboratory evaluation.
The risks and benefits of available treatment alternatives for male infertility largely depend on the cause for the
disorder. Dr. Daiter reviews the clinically accepted treatments for specific known causes, the appropriate use of fertility
medications, intrauterine inseminations for mild to moderate abnormalities, the more recent use of assisted fertilization
(such as intracytoplasmic sperm injection or ICSI) and when to consider donor sperm.