Complete Semen Analysis
The Complete Semen Analysis is the primary test performed to inform and guide the clinician in the evaluation of male infertility. It is important for the sample to be collected into a sterile container by masturbation after 2 to 3 days of abstinence from ejaculation and examined within one (1) hour of collection in order to obtain the most accurate results. Time of collection and days of abstinence are noted on the check-in form. The volume, color, viscosity (consistency), and pH are checked after the specimen is transferred to a test tube. A small amount of the well-mixed semen is placed in a Microcell™ counting chamber slide to calculate sperm density. Differential motility, agglutination, round cells per high power field, an estimation of morphology, and the presence of any bacteria can also be determined from the counting chamber or from a direct wet mount slide. Strict morphology using the Krueger system involves staining a semen smear on a slide and examining the sperm under higher magnification with refraction oil.
The Complete Semen Analysis (also called a comprehensive semen analysis) is usually the first and most common test ordered to check a couple’s fertility. Unfortunately, not all labs examine or report out all semen parameters in the same way. The following is a guideline that our laboratory uses in evaluating and reporting a semen analysis that will hopefully remove some of the mystery. The source of these methods and parameters is the World Health Organization (WHO) Laboratory Manual for the Examination and Processing of Human Semen, 5th edition, 2010. Some labs still use the WHO 4th edition, so be sure you know which system the lab is using to ensure proper interpretation of results.
The three critical parts of a semen analysis:
Parameter Units What it measures / How Normal Range
Volume mL How much “liquid” volume is in the sample. >1.5 mL
The volume is read of the markings on a 15mL
conical centrifuge tube.
Density M/mL The number of sperm (in millions) in a volume >15.0 M/mL
of 1 mL of the sample. Sometimes called “count”
or concentration. A counting chamber, like the
Microcell™, is used to calculate the density from
a small drop of the sample.
Motility % The percentage of sperm seen that have some >40%
movement or motion. 100 to 200 sperm are
examined. If 35 out of the 100 have motion, the
motility is 35%, etc. Motility is broken down to:
immotile (IM), non-progressive (NP) and
World Health Organization Manual for the Processing of Human Sperm and Cervical Mucous Vol. 5 2010