Intracytoplasmic sperm injection (ICSI)

Preparing for ICSI

The procedure involves the injection of live sperm into the cytoplasm of the egg, the substance found in the middle of the egg, which is similar to a gel. After a fertilised egg (embryo) has been created with the injection of live sperm, the fertilised egg can be transferred to your uterus (womb).

ICSI slightly differs from traditional IVF treatment methods as the sperm is injected into the eggs. Whereas, in traditional IVF methods, the sperm penetrates the egg naturally.

How does ICSI work?

Step 1: Consent and screening

Before you have ICSI treatment, you will need to fill in the necessary forms and provide your consent. There may also be a few screening tests to take. These are usually blood tests that check for infections such as HIV, hepatitis B and hepatitis C.

Step 2: Fertility medicines

As with traditional IVF treatment, you will need to take daily hormone injections for 10 to 12 days to stimulate your ovaries, which helps to produce mature eggs for the fertilisation process. You will be seen regularly in the clinic so your doctor can monitor the ovary stimulation stage. This will be carried out by using ultrasound to check on the development of your eggs and how well your ovaries have responded to the fertility medicines. You will then be informed when the eggs are ready for collection.

Step 3: Egg retrieval

Once the day of the egg retrieval has been decided by your medical team, your eggs will be collected. This day will be determined by your response to the fertility medicines, your medical history and your ultrasound scan results.

Approximately 36 hours before your procedure, you will have a trigger injection to ensure ovulation occurs and the eggs are released. During the procedure your eggs will be extracted from the ovaries through a fine needle. You will be provided with pain relief, and oxygen to help with your breathing, throughout.

Step 4: Sperm retrieval

If you are using the sperm of your partner rather than a donor, they will be asked to provide a sperm sample on the same day as the collection of your eggs.

Step 5: Injection of eggs

When both the eggs and sperm are ready, the injection is done in a laboratory. Each egg will be injected with a single sperm. The best sperm cells from the partner or donor will be selected. If fertilisation is successful, the embryos are cultured in a laboratory incubator for a maximum of six days, before the best quality fertilised eggs are selected.

Step 6: Embryo transfer

Once the embryos have successfully developed, the best fertilised egg will be transferred to your uterus. Only one will be transferred usually, as multiple transfers could increase your chances of having twins or triplets. However, if you are over 40 years old, two might be transferred to increase your likelihood of conceiving. The fertilised egg will be transferred into your uterus using a fine catheter (a thin medical tube) and guided by ultrasound for accuracy.

How long does ICSI treatment take?

Although one cycle of ICSI treatment takes around four to six weeks, the egg and sperm collection process itself only usually takes half a day to complete. If fertilisation is successful, you’ll return to the clinic two to five days after collection for your embryo transfer.

ICSI success rate

ICSI is considered the best option for couples who can’t conceive due to male infertility. Several factors can influence the success rate of ICSI, including:

• age: patients under the age of 35 have the best prognosis
• lifestyle: smokers have a lower pregnancy rate; weight, because obesity also has a negative impact on the pregnancy rate
• anti mullerian hormone (AMH) level: having a high level of this hormone indicates a higher egg count, and therefore a higher cumulative pregnancy rate.

Previous studies have corresponded women’s chances of success from ICSI to their age:

• under 35 years old – 42.8%
• from 35 to 39 years old – 36.3%
• over 40 years old – 20%

On average, we expect 50% of couples to achieve a positive pregnancy test and 33% to have a baby, but success is highly dependent on the age of the woman. These results compare favourably with those from other centres in the UK and worldwide. If ICSI doesn’t work the first time, don’t get discouraged, because you can usually try the treatment again.

ICSI risks

Among the risks associated with ICSI treatment are:

• there is a chance (of less than 5%) that some eggs could be damaged during the insertion of the needle
• you are more likely to have a baby with a chromosomal abnormality in the X or Y chromosomes when conceiving with ICSI compared to having sex. Sex chromosome abnormalities are linked to a higher risk of; miscarriage, your child having learning disabilities, your child having heart issues, or your child being infertile when they are older.