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Date: 16-2-2016
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Seminal fluid analysis
Semen is an organic fluid, also known as seminal fluid, that usually contains spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize female ova. In humans, seminal fluid contains several components besides spermatozoa: proteolytic and other enzymes as well as fructose are elements of seminal fluid which promote the survival of spermatozoa and provide a medium through which they can move or "swim". The process that results in the discharge of semen is called ejaculation.
A semen analysis (plural: semen analyses) evaluates certain characteristics of a male's semen and the sperm contained in the semen. It may be done while investigating a couple's infertility or after a vasectomy to verify that the procedure was successful.
Relation to fertility
The characteristics measured by semen analysis are only some of the factors in semen quality. One source states that 30% of men with a normal semen analysis actually have abnormal sperm function. Conversely, men with poor semen analysis results may go on to father children.
Collection methods
The most common way to collect a semen sample is through masturbation, directing the sample into a clean cup. A sample may also be collected during intercourse in a special type of condom known as a collection condom. Collection condoms are made from silicone or polyurethane, as latex is somewhat harmful to sperm. Finally, if a blockage in the vas deferens is suspected to impede fertility, semen can be taken directly from the epididymis. Such a collection is called per cutaneous epididymal sperm aspiration (PESA). Alternatively, the testicular tissue itself, instead of the sperm produced can be investigated. Then, the collecting method is called TESE.
Postprocedure Care
spermatozoa. However, one recent study found that sperm motility increased significantly with coffee drinking and with smoking when evaluated in infertile couples.
Client and Family Teaching
some have been shown to impair the activity of or damage sperm as well as oocytes.
Factors That Affect Results
Other Data
Repeat testing may be necessary because results vary with samples.
Parameters
Examples of parameters measured in a semen analysis are: sperm count, motility, morphology, volume, fructose level and pH.
Sperm count
Over 15 million sperm per milliliter is considered normal, according to the WHO in 2010. Older definitions state 20 million. A lower sperm count is considered oligozoospermia. A vasectomy is considered successful if the sample is azoospermic.
Total sperm count
Total sperm count, or total sperm number, is the total number of spermatozoa in the entire ejaculate. By WHO, lower reference limit (2.5th percentile) is 39 million per ejaculate.
Motility
The motility of the sperm is evaluated. The World Health Organization has a value of 50% and this must be measured within 60 minutes of collection. WHO also has a parameter of vitality, with a lower reference limit of 60% live spermatozoa. A man can have a total number of sperm far over the limit of 20 million sperm cells per milliliter, but still have bad quality because too few of them are motile. A more specified measure is motility grade, where the motility of sperm are divided into four different
grades:
- Grade 4: Sperm with progressive motility. These are the strongest and swim fast in a straight line. Sometimes it is also denoted motility a.
- Grade 3: (non-linear motility): These also move forward but tend to travel in a curved or crooked motion. Sometimes also denoted motility b.
- Grade 2: These have non-progressive motility because they do not move forward despite the fact that they move their tails.
- Grade 1: These are immotile and fail to move at all.
Morphology
The morphology of the sperm is also evaluated. With WHO criteria as described in 2010, a sample is normal if 4% or more of the observed sperm have normal morphology.
Volume
The volume of the sample is measured, volumes between 1.0 mL and 6.5 mL are normal; WHO regards 1.5 ml as the lower reference limit. Low volume may indicate partial or complete blockage of the seminal vesicles, or that the man was born without seminal vesicles. In clinical practice, a volume of less than 2 mL in the setting of infertility and absent sperm should prompt an evaluation for obstructive azoospermia.
Fructose level
The level of fructose in the semen is measured. WHO specifies a normal level of 13 umol per sample. Absence of fructose may indicate a problem with the seminal vesicles.
pH
The pH of the sample is measured. WHO criteria specify normal as 7.2-7.8. Acidic ejaculate (lower pH value) may indicate one or both of the seminal vesicles are blocked. A basic ejaculate (higher pH value) may indicate an infection. A pH value outside of the normal range is harmful to sperm.
Liquefaction
The liquefaction is the process when the gel formed by proteins from the seminal vesicles is and the semen becomes more liquid. It normally takes less than 20 minutes for the sample from a thick gel into a liquid. An abnormally long liquefaction (more than 30 minutes at 37 24 ċ may indicate an infection.
MOT
MOT is a measure of how many million sperm cells per ml are highly motile , that is, approximately of grade 4, or sometimes also taking grade 3 into account. Thus, it is a combination of sperm count and motility.
Total motile spermatozoa
Total motile spermatozoa (TMS) or total motile sperm count (TMSC) is a combination of sperm count, motility and volumes, measuring how many million sperm cells in an entire ejaculate are motile.
Others
The sample is tested for white blood cells. A high level of white blood cells (over 1 million per milliliter) may indicate an infection.
Abnormalities
Computer Assisted Semen Analysis (CASA) is a catch-all phrase for automatic or semi-automatic semen analysis techniques. Most systems are based on image analysis, but alternative methods exist such as tracking cell movement on a digitizing tablet. Computer-assisted techniques are most-often used for the assessment of sperm concentration and mobility characteristics, such as velocity and linear velocity. Nowadays, there are CASA systems, based on image analysis and using new techniques, with near perfect results, and doing full analysis in a few ^seconds. With some techniques, sperm concentration and motility measurements are at least as reliable as current manual methods.
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