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.