Sperm Counts
Laboratories performing sperm “counts,” in general, vary in the details that they provide
the physician requesting the “count.” A general sperm count as part of a fertility
evaluation should include the total density or count (20 million per ml or above) and the
motile density (8 million per ml or higher). The motile density is perhaps the most
important part of the semen analysis, as it reports the total number of sperm thought
capable of progressing from the site of sperm deposition to the site of fertilization. This
value is essential in both allowing a determination regarding whether or not a semen
analysis is “normal,” as well as in providing prognostic information should advanced
reproductive medical assistance be required. (Numbers in italics are what “normal”
values should be.)
Definitions of “abnormal” counts:
 Polyzoospermia: Excessively high sperm concentration
 Oligozoospermia: Sperm count less than 20 million/ml
 Hypospermia: Semen volume < 1.5 ml
 Hyperspermia: Semen volume > 5.5 ml
 Aspermia: No semen volume
 Pyospermia: Leukocytes (germ fighter cells) present in semen
 Hematospermia: Red blood cells present in semen
 Asthenozoospermia: Sperm motility < 40%
 Teratozoospermia: > 40% of sperm seen are of abnormal form
 Necrozoospermia: Non-viable (“dead”) sperm
 Oligoasthenozoospermia: Motile density < 8 million sperm/ml
Sperm Morphology (Shape and Appearance)
The evaluation of sperm size, shape, and appearance characteristics should be
assessed by carefully observing a stained sperm sample under the microscope. The
addition of colored dyes (stains) to the sperm allows the observer to distinguish
important normal landmarks (characteristics) as well as abnormal findings. Several

methods of staining sperm are used, and the method employed should be one with
which the examiner is comfortable and experienced.
Several different shapes or forms of human sperm have been identified and
characterized. These forms fall into one of four main categories: normal forms,
abnormal head, abnormal tail, and immature germ cells (IGC), as described as follows:
Normal Forms
Normal sperm have oval head shapes, an intact central or “mid” section, and an
uncoiled, single tail.
Abnormal Heads
Many different sperm head abnormalities may be seen. Large heads (macrocephalic),
small heads (microcephalic), and an absence of identifiable head are all seen in
evaluations. Tapering sperm heads, pyriform heads (teardrop shape) and duplicate or
double heads have also been seen. Overall (gross) abnormalities in appearance may
be termed “amorphous” changes.
Abnormal Tails
Coiling and bending of the tail are sometimes seen. Broken tails of less than half the
normal length should be categorized abnormal. Double, triple, and quadruple tails are
sometimes seen and are considered abnormal. Cytoplasmic droplets along the tail may
indicate an immature sperm.
Immature Germ Cells (IGCs)
White blood cells (WBCs, germ fighters) in the semen should rarely be seen. It is very
difficult to distinguish between an immature germ cell and a WBC. Because the
presence of WBCs in the semen (pyospermia) can be a serious concern, if a report of
“many IGCs” is delivered, it becomes very important to assure that these cells are not,
instead, WBCs.
Sperm Motility (Movement)
Sperm motility studies identify the number of motile (moving) sperm seen in an
ejaculate specimen. Here again, as in many other sperm studies, many laboratories use
“normal” values that are out of date and inaccurate. Many labs will assess sperm
motility upon receipt of the specimen, and again at hourly time intervals for four to
twenty-four hours. It is well known that sperm motility is a temperature dependent sperm
function, so the handling and processing of specimens is critical. It is for this reason that
we, except in very rare instances, require that specimens be evaluated only in a
laboratory such as our own, where we are able to tightly control laboratory conditions.

We have found the repeated testing of sperm over time for motility adds little to the
evaluation of motility over the initial sperm motility assessment. Sperm are known not to
survive well for extended periods of time in semen, and in nature, sperm very rapidly
leave the semen to enter the cervical mucus. Many laboratories consider “normal”
sperm motility to be 40 percent or greater.
The following is a discussion of common sperm motility characteristics.
Asthenozoospermia
Decreased sperm motility. If found to be present, exam should be repeated to assure
that laboratory conditions did not cause the problem. Frequent causes include abnormal
spermatogenesis (sperm manufacture), epididymal sperm maturation problems,
transport abnormalities, and varicocele. These conditions should all be looked for if
sperm motility is repeatedly “low.”
Necrozoospermia
A total absence of moving sperm. It is vital, if sperm are seen but are not moving, to
carry out studies (vital stains) to see if the sperm seen are alive. It is possible to have
sperm with normal reproductive genetics that are deficient in one or several of the
factors necessary to produce motility. We have achieved several successful
pregnancies employing microinjection of healthy, non-motile sperm directly into the egg
(ICSI).
Chemical and Biochemical Semen Characteristics
Semen Acid-Base Balance (pH)
The pH of semen is measured using a specially treated paper blot that changes color
according to the pH of the specimen that it is exposed to. The pH of normal semen is
slightly alkaline ranging from 7.2 to 7.8. Prostatic secretions are acidic while the
secretions of the seminal vesicles are alkaline. Therefore, alterations in pH may reflect a
dysfunction of one or both of these accessory glands. The pH of semen has not been
generally found to have a major influence on a man’s fertility potential.
Color and Turbidity
Semen is normally translucent or whitish-gray opalescent in color. Blood found in
semen (hematospermia) can color the semen pink to bright red to brownish red. The
presence of blood in semen is abnormal and should be reported. The presence of
particles, non-liquified streaks of mucus, or debris requires further evaluation.

Liquefaction
Semen is normally produced as a coagulum. The specimen will usually liquefy within 30
minutes. The failure to liquefy within one hour is abnormal. Excellent methods for
correcting this problem in the laboratory are available.
Viscosity
Non-liquefaction and excessive viscosity are two separate conditions. Viscosity is
measured after complete liquefaction has occurred. Viscosity is considered “normal” if
the liquefied specimen can be poured from a graduated beaker drop by drop with no
attaching agglutinin between drops. The role of hyper (excessive) viscosity is being
studied, but it seems possible that this condition may interfere with the ability of sperm
to travel from the site of deposition into the cervix or uterus.