ICSI,
or Intracytoplasmic Sperm Injection, is the most
widely used specialized insemination technique. It
is a newer advancement in reproductive technology in
which procedures are performed on eggs under a
specially constructed microscope in a process known
as micromanipulation. ICSI enables fertilization in
cases of very low sperm counts, of non-motile sperm,
of severe sperm abnormalities, and in cases in which
sperm have poor penetration ability. It may also be
indicated in couples who had no fertilization in
previous IVF attempts.
Sperm used for ICSI may be obtained from a fresh
ejaculate, electroejaculate, epididymal aspirate or
from the testis by the isolation of sperm from
biopsy specimens. The technique involves injecting
a single sperm directly into the egg. After
injection of the sperm, the eggs are incubated for
16-18 hours, and then examined for evidence that
fertilization has occurred. The resulting embryos
can then either be transferred back to the woman's
uterus using standard IVF techniques (or to the
fallopian tubes using ZIFT), or can be frozen for
transfer at a later time.
