The most important laboratory investigation of male infertility is the semen analysis.
It provides information about the volume of semen and the sperm count, sperm motility (swimming), and sperm morphology , sperm shape.
Semen may be obtained by masturbation or intercourse using a special nontoxic condom.
A period of abstinence from ejaculation (sex and masturbation) from 2 to 5 days, delivery of the sample to the laboratory within 1 hour of collection, and avoidance of exposure to lubricants or extremes of temperature are indicated.
Because of the variability of results, several semen analyses at intervals of 2 or more weeks are necessary in a man with an abnormality in the first test. Even with complete collection of samples, there is variability caused by counting error, other technical errors, and differences in the ejaculate from day to day.
These large variations need to be remembered when interpreting results of semen analysis.
Sperm antibodies – tests for sperm antibodies should be done routinely on all men being evaluated for infertility. The presence of high levels of antibodies against sperm might be responsible to low sperm movement and lack of binding of sperm to the egg, hence, no fertilization.
Variations in Semen Volume and Appearance
Low semen volume suggests incomplete collection, short duration of abstinence from ejaculation before the test, absence or obstruction of the seminal vesicles, or androgen (male hormone) deficiency.