Intracytoplasmic sperm injection (ICSI)

What is intracytoplasmic sperm injection (ICSI)?

Intracytoplasmic sperm injection (ICSI) – sometimes referred to as ICSI-IVF – is a form of in-vitro fertilisation (IVF) fertility treatment.

ICSI is considered one of the best treatment options when male infertility is preventing you and your partner from having a baby. It is a highly technical fertility treatment where a single sperm is injected into the centre of each egg to try to achieve fertilisation.

At the Assisted Conception Unit at Guy’s Hospital, we have been at the forefront of fertility care for over 30 years. We are proud to have been the first NHS unit in the country to have a baby born from the ICSI technique.

When is ICSI recommended?

ICSI is commonly recommended for men with sperm problems. The procedure is advisable for men with:

• abnormally shaped sperm
• high levels of antibodies against his sperm – this can affect the ability of the sperm to bind to the egg
• low sperm count
• no sperm in his ejaculate, but sperm can be obtained from the testicles using surgery
• retrograde ejaculation – the sperm passes back into the bladder and can be found in the urine
• sperm with poor motility
• unexplained failed fertilisation of all the eggs from previous IVF treatments

ICSI can also be recommended when sperm has DNA damage, or when the sperm used for fertilisation has been recovered through surgical sperm retrieval (a procedure that collects sperm from the epididymis tubes which attach to the testicles).

ICSI may also be considered if fertilisation failed when you had traditional IVF treatment. If you are using frozen eggs, you will need to use ICSI to successfully fertilise them. This is because eggs that are frozen and then thawed will have a hardened zona pellucida (the thick coat that covers the eggs). ICSI is also suitable when donor eggs are used for IVF treatment.

If you’re interested in ICSI or fertility treatment in general, get in touch today to speak with our dedicated team.

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 while, 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 6 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, 2 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 4-6 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 2-5 days after collection for your embryo transfer.

Contact our friendly team, who are on hand to answer any fertility questions.

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