ICSI (Intracytoplasmic Sperm Injection)
ICSI is a specialist technique in which a single sperm is injected into the centre of an egg. The technique is commonly used when the sperm to be used is not optimal, often because of low sperm count or motility (its ability to swim towards the egg). ICSI is also preferable for a number of reasons, for example combined with pre-implantation genetic diagnosis (PGD) or when sperm DNA fragmentation is high.
How does ICSI work?
Fertility drugs are given to the female partner to stimulate the production of multiple eggs which are contained in follicles on the ovaries. Progress is monitored using ultrasound and blood tests.
When the leading follicle reaches 17-22mm, the final preparation for the egg collection is done. This involves a hormone injection of human chorionic gonadotrophin (hCG), which is given approximately 36 hours before the egg collection. The hCG injection stimulates the eggs to mature.
The egg collection procedure is usually done using light sedation. An ultrasound guided vaginal probe is used to locate the follicles and aspirate its contents. The eggs are then placed in culture in our state of the art laboratory. It is difficult to determine the number of eggs that will be collected until the procedure. In rare cases, no eggs are collected.
In the laboratory, the embryologists will inject one sperm into each egg. In some cases, sperm may need to be surgically removed.
Once the embryos have developed, the embryologist will select one to be transferred back to the womb during an embryo transfer procedure. It is a painless and quick procedure. The embryo(s) are loaded into a fine catheter and this is placed into the womb and the embryo(s) are expelled. After the embryo transfer, the patient can resume her usual activities.
Two weeks after the embryo transfer, a pregnancy test is performed, and CRGH should be informed of the result.
How long do ICSI embryos take to develop?
The day after the sperm is injected each egg, embryologists will look for signs of fertilisation. The following day they will check to see if the embryo has cleaved. Embryos can be transferred at any stage from day 2 up to day 6. By day 5 or 6, the embryos should reach the blastocyst stage.
The embryologists monitor and grade the embryos very carefully. In the majority of cases, if the embryos have developed well we would recommend a single embryo to be transferred to reduce the risk of twins. If a blastocyst transfer is going to take place, we will only normally transfer one embryo in patients under 40 years.
What happens to embryos that are not transferred?
All good quality embryos that are not transferred will be frozen. CRGH has a very high pregnancy rate for frozen embryo transfers. This gives a very high chance of getting pregnant in a subsequent cycle without having to go through the whole IVF procedure again.
What are my chances of having a baby with ICSI?
An embryologist will examine your sperm under a microscope and decide whether ICSI could increase your chances of fathering a baby. The average number of eggs that get fertilised using ICSI is around 70%. In rare cases, there is failure to fertilise.
You are more likely to become pregnant with twins or triplets if more than one embryo is transferred during the process. Your clinician will recommend single embryo transfer (SET) if they consider it to be the best option for you.
Is ICSI for me?
We may recommend ICSI if:
- The male partner has a very low sperm count
- The male partner’s sperm has problems such as poor motility (not moving normally) or poor morphology (abnormal shape)
- Previous IVF attempts have failed
- Sperm needs to be collected surgically from the male’s testicles or epididymis, for instance if he’s had a vasectomy
- You are using frozen sperm in your treatment which is not of optimum quality
- You are undergoing pre-implantation genetic diagnosis or screening
Success Rates at CRGH