Semen analysis: The normal and the abnormal
In Singapore, one in 5 to 6 married couples have problems getting pregnant. Half of these difficulties is due to low sperm counts and/or abnormal sperm function. Thus, in the assessment of male fertility, it is important to test the semen, which contains the sperm and the fluid secreted by the male genital tract (the seminal vesicles, the prostate gland and the bulbourethral glands).
Collection of sample:
Semen can be collected by:
· Masturbation and collection into a wide mouthed cup
· Using a non-spermicidal condom during sexual intercourse
· Withdrawal before ejaculation during sexual intercourse
· Electrical stimulation or prostatic message
Masturbation is usually the preferred method.
Preparation for Semen analysis
· Abstinence of 3-4 days is recommended. According to World Health Organization in 1999, the optimal abstinence period is 2-7 days.
· Avoid alcohol, caffeine, herbal medications and lubricant use.
· Keep the semen at body temperature.
· Send the sample to the laboratory within an hour.
· Do not take the test if you are sick or stressed.
What are normal results?
Semen analysis includes the evaluation of various sperm parameters such as the volume of semen, concentration of sperm, the vitality, motility and morphology) of sperm.
The results should be compared with the World Health Organization reference values published in 2010.
• semen volume: 1.5 ml or more
• pH: 7.2 or more
• sperm concentration: 15 million spermatozoa per ml or more
total sperm number: 39 million spermatozoa per ejaculate or more
• total motility (percentage of progressive motility and non-progressive motility):
40% or more motile or 32% or more with progressive motility
• vitality: 58% or more live spermatozoa
• sperm morphology (percentage of normal forms): 4% or more.
A low or excessive semen volume could indicate infection of the prostate and seminal vesicles.
The normal appearance of semen is whitish to gray and opaque. Semen that has a red or brown tint could indicate the presence of blood, while a yellow tint could indicate infection.
A pH level higher than 8.0 may suggest an infection. A pH of less than 7.0 could indicate the specimen is contaminated or that the ejaculatory ducts are blocked.
Semen is initially thick and takes 15 to 30 minutes to liquify to facilitate the sperm to move up the genital tract. If semen is slow to or does not liquefy, it may indicate an infection.
Sperm concentration refers to the number of sperm found in one milliliter of semen. Low sperm count or oligospermia will make conception difficult. If no sperm are found, the condition is called azoospermia.
Sperm morphology refers to the shape of the head, neck and the tail. A normal shaped sperm that fertilizes a normal egg will result in a healthy baby.
Motility is the percentage of sperm which moves. The movement may be forward either in line or in a large circle This is important for the sperm to travel up the female genital tract to fertilize the egg.
Sperm vitality refers to the percentage of live sperm in the semen sample.
If Your Results Are Abnormal
As semen test in the individual can vary from day to day and from laboratory to laboratory, one abnormal result is not necessarily a sign of impaired male fertility. It is common for doctors to repeat the tests in order to have a better assessment of the sperm health. According to the American Association for Clinical Chemistry (AACC), the tests should be conducted at least seven days apart and over the course of two to three months