Factors Semen Analysis Tests
Semen analysis involves collecting a sample of semen and inspecting it under a microscope. It gives an idea of the health and fertility potential of sperm cells.
The WHO (World Health Organization) has defined the features of sperm to be tested and provided standard reference values for semen and sperm parameters.
To accurately understand a semen analysis report, you should know the reference values and the cut-off line for each characteristic.
A sufficient volume of semen is important for accurate sperm analysis. If the semen volume is too small, the concentration and sperm count may be altered. It may help to practice abstinence for a few days before collecting the sample to ensure a sufficient volume of semen.
A volume of less than 2 mL per ejaculate is called hypospermia. This may be caused factors such as:
- Low sex hormone levels (hypogonadism)
- Blockage of ducts that transport semen
- Obstruction in the urethra
- Retrograde ejaculation
In contrast, hyperspermia refers to a volume of more than 6mL per ejaculate. The causes include:
- Excessive secretion of semen from the accessory glands
- Prolonged abstinence before collection of samples
pH of Semen
pH is a measurement of how acidic or basic the semen is. Semen is usually neutral or slightlhy basic to counteract the more acidic pH of the vagina. The normal pH of semen is 7 to 8.
Abnormal semen pH may result from:
- Acidic (low) pH: Urinary tract infections, sexually transmitted infections, infection or inflammation in the reproductive tract
- Basic (high) pH: Blockage of the tubules that produce semen
Sperm concentration is the density of sperm cells per milliliter of semen. The normal range for sperm concentration is 15 to 30 million sperm per mL of the semen.
Azoospermia is a term that describes the total absence of sperm in the ejaculate. A sperm concentration of less than 15 million is referred to as oligospermia. Azoospermia and oligospermia can make it more difficult to conceive.
Sperm count is the total number of sperm per ejaculate. You can calculate it by multiplying sperm concentration by the volume of semen in milliliters. A normal sperm count is considered 39 million or more sperm per ejaculate.
A low sperm count can be caused by many factors, including:
- Medical conditions like diabetes and high blood pressure
- Decreased physical activity
- Poor nutrition
- Excessive alcohol consumption
- Recreational substance use
- Cancer or cancer treatment
Sperm motility is the ability of sperm to move and swim. This movement is crucial for sperm to be able to reach an egg to fertilize it.
A normal sperm motility is considered 40% or more motile sperm in the ejaculate. If you have low sperm motility, the fertility potential may decrease.
Sperm morphology, or shape, is another important parameter. Sperm consist of a head, neck (mid-piece), and tail, and defects in morphology may occur in any piece. Spermatogenesis typically produces numerous structurally defective sperm in healthy individuals. However, at least 4% of sperm cells should have normal morphology to give you a good chance of conception.