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In normal
fertility, a million or more sperm must be mustered
to fertilize one egg. In ICSI, the revolutionary
new treatment for male factor problems, the sides
are more even. A single sperm is injected into an
egg. In theory it takes just one sperm for each egg
to be fertilized.
ICSI stands for
intracytoplasmic sperm injection, a
technique perfected by Dr. Andre Van Steirteghem
and colleagues at the Center for Reproductive
Medicine at University Hospital, Brussels Free
University in Belgium. They have had success with
men with no motile sperm; they have even had
pregnancies with small numbers of sperm, obtained
from testicular biopsies or from specimens of the
epididymis obtained at microsurgery.
Their successes
using ICSI approach results obtained from regular
IVF. A new standard has been set for infertility
specialists elsewhere to meet. The challenge is
that the procedure is highly technical; it requires
sophisticated equipment, specially trained
personnel, and the time to learn and perfect the
technique. All of these requirements also make ICSI
expensive to provide.
ICSI involves
taking a microneedle, puncturing through the outer
layers directly into the interior of the egg, and
injecting a single sperm inside. First, the semen
is specially prepared. The fluid is removed to
collect as many motile sperm as possible. Two types
of glass micropipettes are needed -- one for
holding the egg, one for injecting the sperm. The
egg is held in a fixed position, and a single sperm
is aspirated into the injection pipette, which is
then placed through the zona pellucida (a
relatively tough outer coating of the egg) and
pushed into the ooplasm (interior of the egg). ICSI
is carried out under magnification of 400
power.
After injection of
the sperm, the eggs are incubated for 16-18 hours,
then examined for possible damage and for evidence
that fertilization has occurred. The resulting
undamaged embryos can then either be transferred
back to the woman's uterus, using standard IVF
techniques "EMBRYO
IMPLANTATION",
or can be frozen for transfer at a later
time.
In time, more
programs will offer this new technique. Time and
experience will also provide more answers about the
success and safety of the procedure. Nevertheless,
ICSI promises major advances in male infertility if
the successes of the pioneering programs can be
replicated in clinical practice.
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