Intra cytoplasmic sperm injection (ICSI)

What is intracytoplasmic sperm injection (ICSI)?

Intracytoplasmic sperm injection (ICSI) is when a single sperm is injected into an egg. The fertilised egg is then placed into the uterus. This method may be recommended for couples who are experiencing fertility difficulties due to sperm-related infertility problems. 

Am I a candidate for ICSI?

If you are having trouble naturally conceiving due to you (or your partner) having a low sperm count, you may be a good candidate for intracytoplasmic sperm injection (ICSI). 

To determine whether this fertility treatment is right for you, speak with your doctor about your options. 

Intracytoplasmic Sperm Injection Stages

There are seven main stages of Intracytoplasmic sperm injection:

1. Down regulation

Before beginning fertility treatment drugs are given to suppress the natural hormones produced in a normal menstrual cycle. This results in the ovaries responding more effectively to fertility drugs.

Possible complications

If the treatment is not successful, you may find your periods are irregular for a couple of months before returning to normal.

2. Stimulation of the ovaries

In an ICSI cycle fertility drugs are given in order to control the growth of follicles to produce between 10-15 eggs. Sometimes the ovaries respond inadequately to the drugs and the treatment cycle may be cancelled. A further attempt can then be arranged and the amount of stimulating drugs may be increased.

Possible complications

Ovarian hyperstimulation syndrome (OHSS) may occur if the ovaries over stimulate and produce large numbers of eggs or high levels of oestrogen, but this is rare. Symptoms include abdominal discomfort, but this should settle with rest and mild painkillers.

3. Monitoring egg development

The growth of the follicles is monitored by vaginal ultrasound scans regularly from approximately the sixth day of injections. When the follicles are the best size, a different hormone injection is given to induce the final stages of egg maturation. This injection is given 34 to 36 hours before the eggs are collected.

4. Ultrasound guided egg collection

The most common technique is by using an ultrasound-guided needle, carried out under a light general anaesthetic or intravenous sedation. The procedure, which takes about 30 minutes, is carried out using vaginal ultrasound. Remember, you will not be able to drive after this procedure. A needle is guided along the probe through the vaginal wall and into the ovary. Each follicle in turn is punctured and drained of the fluid it contains. The embryologist examines this to determine whether an egg is present.

On average eggs are retrieved from about 80 per cent of mature follicles. The eggs recovered will be inseminated using sperm provided by the recipient’s partner. Those that fertilise will be cultured in the embryology lab. In some cases no eggs will be collected, but this is very rare.

5. Sperm collection

Your partner will be asked to produce a sample of sperm either before or after the egg collection depending on the time of the procedure. He shouldn’t have sex for 72 hours before the egg collection. Usually only one sample is needed. If donor sperm <link> is being used, the sample will be taken from frozen storage. When donor sperm is used in any assisted conception technique recommendations from the Human Fertilisation and Embryology Authority (HFEA) and the Royal College of Gynaecologists are followed.

6. Fertilisation

A single sperm is injected directly into the centre of the egg (cytoplasm). In this way, the sperm is not required to penetrate any of the barriers surrounding the egg. Fertilisation occurs if the head of the sperm and the egg fuse together. Once injected, the eggs are incubated for a period of 16 hours, after which the embryologist will check to see if fertilisation has taken place.

7. Embryo transfer

Embryos are transferred through the cervix into the uterus using a catheter. Usually two to three embryos are transferred to increase the chance of having a baby. No more than three embryos may be transferred, under HFEA guidelines.

For more information, and if you have any queries, speak to your consultant.


ICSI may be appropriate if you have:

• Previous failed fertilisation or low fertilisation rate with conventional IVF

• No sperm or extremely low sperm count

• High levels of antisperm antibodies (these occur when the body becomes sensitised to sperm, causing an immune system response that destroys the sperm).

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