The characteristics of a man’s semen are critical to fertility. Both the health and number of the sperm cells and the composition of the supporting seminal fluid are important. The seminal fluid contains a number of substances, designed to improve the sperm cells’ chances of reaching an ovum, and is produced in three glands: the prostate, the seminal vesicles, and the Cowper’s glands (bulbourethral glands). These substances include sugars, amino acids, enzymes, and prostaglandins, among others.
Sperm Cell Analysis (Sperm Count)
Only healthy sperm cells (spermatozoa) can fertilize an ovum. If too few healthy sperm cells are produced, the odds of pregnancy are slim, so sperm count is important.
A normal sperm cell has a head, which contains the genetic material (DNA) and enzymes allowing it to fertilize an egg cell, and a long, whiplike tail, which makes the cell motile (able to move about under its own power). A single ejaculation should contain between 200 million and 500 million sperm.
Sperm cell analysis looks at the following:
- Sperm concentration: This is a measure of the number of sperm cells in a volume of semen.
- Total sperm: This is a count of the total number of sperm cells.
- Sperm motility: This includes both a measure of the percentage of sperm cells that are motile, and an evaluation of how well the sperm are able to move. Healthy sperm should be able to move vigorously in a straight direction.
- Number of normal and defective sperm: With hundreds of millions of sperm cells, a few defective sperm are not unusual. Too many defective sperm can cause male infertility.
- Number of immature sperm: Only fully mature sperm can fertilize an egg. Normally, immature sperm should not be ejaculated. Sperm production, called spermatogenesis, is a very sensitive process, and a number of factors (for example, hormone deficiency or improper temperature) can prevent sperm from maturing properly.
Seminal Fluid Analysis
The seminal fluid supports the sperm cells as they travel through the female reproductive tract, and problems with its composition can negatively impact fertility. Seminal fluid is typically analyzed to measure the following:
- Volume: An adequate quantity of semen per ejaculation improves the chance of pregnancy.
- Consistency: The thickness or viscosity of the semen affects the sperm cells’ ability to swim. Normal semen contains a small amount of mucus to provide a "channel" for the sperm.
- Coagulation and liquefaction: Semen must normally coagulate shortly after ejaculation, to keep it inside the vagina, then liquify, to permit sperm mobility.
- Fructose: This simple sugar serves as the sole energy source for the sperm. Without fructose, the sperm will not have enough energy to swim.
- pH: This value is a measure of how alkaline or acidic the semen is. The vaginal canal is normally very acidic, which helps protect against bacterial infection. The semen must counteract the acid of the vagina by being alkaline; otherwise the sperm will not be able to survive.
- White blood cells: A large number of white blood cells indicates an infection, which may cause infertility and other health problems.
Semen Analysis from Lab Tests Online.