Male factor infertility is a complex problem
and requires the expertise of specially-trained professionals who stay abreast
of new developments in the field. Both the diagnosis and treatment of the male
factor infertility has made significant progress in recent years. We have attempted
to outline both the basic and advanced tests and procedures available at Coastal
Fertility Medical Center. We hope you find the information helpful in this rapidly
advancing field.
What is Male Factor Infertility?
In order for a pregnancy to occur, sperm must
travel from the male genital tract to the egg
in the female and then penetrate the egg. This requires sufficient numbers of
not only moving but functioning sperm that have the ability to undergo the biochemical
process that enables them to fertilize an egg. An impairment in any aspect of
this chain of events is called male factor infertility.
How is Male Factor Infertility Diagnosed?
There is no single test to diagnose for male factor infertility. A work-up for
male factor infertility may include: An analysis of the number of sperm (count);
how many are moving (motility), and
what sperm look like (morphology).
Tests to identify sperm antibodies
to determine the capacity of sperm to function (computer assisted semen analysis;
CASA) and to assess the sperm's ability to attach to (zona binding) and penetrate
the egg (sperm penetration assay; SPA)
may also be performed. Physical examination and semen culture can also be important
components of the male work-up.
Complete Semen Analysis
A complete semen analysis provides the basic starting point in any work-up for
male factor infertility. It consists of a sperm
count, sperm motility, sperm
morphology, live-dead ratio, and cellular content at the microscopic level.
In addition, macroscopic observations of the semen volume, color, pH, and viscosity
are also reported. Recent advances in the analysis of these parameters include
strict morphology (Kruger criteria) for patients with increased abnormal forms
or low motility and CASA for poor motility or idiopathic infertility.
Sperm Antibodies
The presence of antisperm antibodies
can often be detected by the coagulation or clumping of sperm observed during
a semen analysis. Also, unusually low sperm numbers or the presence of "twitching"
sperm movement in the cervical mucus
following a post-coital examination
can often be an indicator of antisperm antibodies. Antibodies to sperm are frequently
observed in patients that have undergone vasectomy reversal. By severely inhibiting
sperm motility or sperm binding
to the egg, sperm antibodies are a major causative factor in male infertility.
Sperm Penetration Assay (SPA)
The ability of human sperm to attach to and penetrate zona-free hamster eggs
is highly correlated with their ability to fertilize human eggs. Men with normal
semen analyses often display poor penetration due to incomplete capacitation
of the sperm. If sufficient numbers are available, the sperm specimen can be
split among 2-3 different preparations in an effort to identify the best treatment
for IUI cycles or In Vitro Fertilization. The standard preparation is with isolate
separation and then additional adjuvants such as test yolk buffer, follicular
fluid, high salt or high protein may be included to improve the results. Furthermore,
the average number of sperm penetrating the egg (penetration index) is a useful
marker for deciding whether or not Intracytoplasmic
Sperm Injection (ICSI) would be the most efficacious treatment to achieve
fertilization.
If an abnormality is found, what treatments
are available?
The male may undergo medical or surgical treatment appropriate to their medical
condition. Additional treatment may include artificial
insemination (AI) of the male's partner with sperm that has been treated
with a variety of methods. Some couples will undergo In
Vitro Fertilization (IVF) using chemical enhancement for the sperm or Intracytoplasmic
Sperm Injection (ICSI).
Anodiant Separation
Isolate is the standard method of separating progressively motile sperm from
non-motile sperm and cellular debris found in semen.
The concentration of Isolate used, length of the Isolate column, and speed of
centrifugation may all be adjusted to improve sperm separation and recovery
in male factor cases that are not severe.
Chemical Enhancement
A number of chemicals have been identified which can be used to improve the
quality of the specimen prior to insemination either vivo or in vitro. In general,
these chemicals act by either improving the motility
of many slow-moving sperm or improving
the capacitation process. Repeated
CASA and/or SPA following the use of
adjuvants often reveals dramatic improvements in results. Examples of motility
enhancers include chymotrypsin, pentoxifylline and deoxyadenosine, whereas TEST-yolk
buffer, follicular fluid, high salt, and high protein have been shown to improve
capacitation.
Micromanipulation
Male factor patients who show severely reduced sperm numbers, motility, or function
often benefit from In Vitro
Fertilization in combination with Intracytoplasmic
Sperm Injection (ICSI). An ICSI procedure can also be successfully applied
to couples in which sperm can only be obtained through a testicular biopsy specimen.
The biopsy is performed by a Urologist,
usually on the day before the oocyte
retrieval.