Intra-cytoplasmic sperm
injection (ICSI) differs from conventional in vitro fertilisation (IVF) in that
the embryologist selects a single sperm to be injected directly into an egg,
instead of fertilisation taking place in a dish where many sperm are placed
near an egg.
ICSI
enables fertilisation to happen when there are very few sperm available.
Your clinic may recommend ICSI if:
·
you have a very low sperm count
·
other problems with the sperm have been identified, such as poor
morphology (abnormal shape) or poor motility (not moving normally)
·
during previous attempts at IVF there was failure of
fertilisation or an unexpectedly low fertilisation rate
·
you need sperm to be collected surgically from the testicles or
epididymis (a narrow tube inside the scrotum, where sperm are stored and
matured); for example because you have had a vasectomy, you do not ejaculate
sperm, or because you have extremely low sperm production
·
you are using frozen sperm in your treatment which is not of
optimum quality
·
you are using embryo testing.
How does ICSI work?
Before your treatment starts you will need to complete various
consent forms and you, and if applicable your partner, may need to have blood
tests to screen for HIV, hepatitis B and C and human T cell lymphotropic virus
(HTLV) I and II.
Treatment then typically involves the following:
For women
You take fertility drugs to stimulate your ovaries to produce
more eggs, as for IVF, and your progress will be monitored through vaginal
ultrasound scans and possibly blood tests.
The eggs are then collected using the same procedure as IVF and
each egg is injected with a single sperm from your partner or donor. The rest
of the process is also the same as IVF.
You are more likely to become pregnant with twins or triplets if
more than one embryo is transferred so your clinic will recommend single embryo
transfer (SET) if they feel it is the best option for you. An embryologist will
examine your sperm under a microscope and decide whether ICSI could increase
your chances of fathering a baby.
The next step depends on whether you are able to provide sperm
without a medical procedure:
·
If you can, you produce a fresh sperm sample on the same day as
your partner’s eggs are collected.
Or:
·
Sperm can be collected directly from the epididymis using a type
of fine syringe. This is known as ‘percutaneous epididymal sperm aspiration’ or
PESA.
·
Sperm can also be retrieved from the testicles, a process known
as ‘testicular sperm aspiration’ or TESA.
·
It is also possible to remove tiny quantities of testicular
tissue from which sperm can be extracted. This procedure is called ‘testicular
sperm extraction’ or TESE. For more information about PESA, TESA and TESE,
speak to your doctor.
·
If you have stored sperm, it will be removed from frozen
storage, thawed and prepared for treatment.
A single sperm is then injected into each egg. ICSI provides the
opportunity for fertilisation to happen, but it is not guaranteed to succeed.
Finally, if fertilisation does take place, the embryos will be
cultured in the laboratory for up to six days and then between one and three of
the best-quality embryos will be transferred to the womb.
Zero sperm count
If you have a zero sperm count (other than caused by vasectomy),
the chances of retrieving sperm surgically by PESA, TESA or TESE may be very
low.
In this situation, you might consider having a surgical
retrieval as a ‘dummy run’ and storing any sperm that are obtained. If no sperm
are retrieved, you may want to consider donor insemination (DI) or IVF with
donor sperm instead.
