Semen
Analysis Reference and Explanations Semen
Analysis is carried out at OVO according to the
W.H.O recommended methods and protocols. Therefore
concentration and motility assessments are performed
in duplicate and averages reported once the validity
of the two scores have been statistically assessed.
MOTILITY
Duplicate assessments are made
for motility to ensure accuracy. Results are reported
as a percentage of sperm in each of the following
groups:
| |
a |
rapid progression |
> 25µm/s |
| |
b |
slow progression |
5-24 µm/s |
| |
c |
non-progressive |
<5 µm/s |
| |
d |
immotile |
|
If motility values are less than
40% overall motility a vitality test will be performed
to assess whether there is any evidence of necrozoospermia
or possibly vital but non motile sperm as seen
in Kartagener’s Syndrome for example.
MORPHOLOGY
Morphology is assessed following
staining and performed using the Tygerberg strict
criteria.
The reference value for Tygerberg is >14%.
However in many men we will see much lower values.
Perhaps of more interest is the TZI value. This
relates to the Teratozoospermic index (or the
Multiple Anomalies Index). The reference value
for TZI is 1.6; studies have shown that above
this value spontaneous pregnancy rates are reduced.
Above 1.9 a very highly significant reduction
in pregnancy rate can be expected. (Joannet
et al, 1988)
ANTISPERM ANTIBODIES
Antisperm antibodies can be present
in semen samples without any other indication
which is why we test all samples for IgG and IgA
antisperm antibodies. A positive result is a level
of binding greater than 50% of the motile sperm.
When a positive result is assessed, the location
of the binding will also be reported. Reports
have shown that positive ASAB associated with
the head in particular can be linked to reduced
pregnancy rates. The W.H.O recommends the following
treatment types by level and location of ASAB:
| >80% |
Head or all locations on sperm |
In Vitro Fertilisation + ICSI |
| 50%-80% |
Head or all locations on sperm |
In Vitro Fertilisation |
| >80% |
Midpiece or tail only |
Intrauterine insemination or
IVF |
| 50%-80% |
Midpiece or tail only |
Intrauterine insemination |
(WHO Manual for the Standardised Investigation,
Diagnosis and Management of the infertile male.
2000)
