Intra-cytoplasmic sperm injection (ICSI)

Spire Cardiff Hospital's Fertility Centre offers a whole range of investigations for couples who are having difficulty conceiving. If you would like to know more about our fertility service please call Ali, Amie or Becky on 029 2054 2509.

What is intra-cytoplasmic sperm injection and how does it work?

Intra-cytoplasmic sperm injection (ICSI) involves injecting a single sperm directly into an egg to fertilise it. The fertilised egg (embryo) is then transferred into the womb a few days later. The development of ICSI means fertilisation is possible even with semen samples that have a very low sperm count.

In vitro fertilisation (IVF) insemination, as opposed to ICSI, involves adding prepared sperm to a dish containing eggs. The sperm swim to the egg and attempt to fertilise it. ICSI may be recommended if there is any reason to believe eggs will not fertilise with conventional IVF. The average fertilisation per egg injected is about 60-70%, and more than 90% of patients have at least one egg fertilised.

There is no difference between ICSI and IVF in terms of the treatment you undergo. The only difference is in the way the eggs are fertilised.

Is ICSI for me?

ICSI is often recommended if:

  • the male partner has a very low sperm count
  • other problems with the sperm have been identified, such as poor morphology (abnormally shaped) and/or poor motility (poor swimmers)
  • sperm antibodies have been detected at significant levels, which prevent sperm binding to the egg
  • previous attempts at in vitro fertilisation (IVF) resulted in failure to fertilise or an unexpectedly low fertilisation rate (below 20%)
  • the male partner has had a vasectomy and sperm have been collected from the testicles or epididymis (TESA/PESA)
  • the male partner does not ejaculate any sperm but sperm have been collected from the testicles (TESA)
  • the male partner has had problems obtaining an erection and ejaculating, which may include men with spinal cord injuries and men with diabetes

For more information see our treatment page for IVF treatment.

Are there any risks with ICSI?

ICSI is a relatively new treatment, introduced in 1992. As such it is unknown whether there are any long-term consequences for children conceived by ICSI. However, since the technique was introduced, thousands of healthy ICSI-conceived children have been born.

Risks that have been associated with ICSI

  • Certain genetic and developmental defects have been recorded in a very small number of children born using this treatment. However, problems that have been linked with ICSI may have been caused by the underlying infertility, such as inherited genetic abnormalities, rather than the technique.
  • A slight increased risk of miscarriage, because the technique uses sperm that may not otherwise have been able to fertilise an egg.
  • A risk of damaging eggs, as the technique involves placing a needle inside the egg and damaged eggs will not fertilise.
  • A possibility that a boy conceived as a result of ICSI may inherit his father’s infertility. It is too early to know if this is the case as the oldest boys born from ICSI are still in their teens.

A low sperm count caused by genetic problems could be passed on to a male child so you may wish to undergo genetic tests before going ahead with ICSI. Infertile men with a very low sperm count, or no sperm in their ejaculate, may be tested for cystic fibrosis genes and for chromosome abnormalities. You may want to discuss the full implications of taking these tests with your clinician or the centre’s counsellor before going ahead.

Other associated risks with ICSI treatment are the same as IVF treatment:

  • A mild reaction to fertility drugs may involve hot flushes, feeling low of mood or irritable, headaches and restlessness. Symptoms are often temporary.
  • Ovarian hyperstimulation syndrome (OHSS) is a serious over-reaction to fertility drugs used to stimulate egg production. It can cause symptoms such as a swollen stomach, stomach pains, shortness of breath, nausea and vomiting. If you start to experience any of these symptoms you must contact the centre immediately.
  • The risk of miscarriage following IVF is the same as in natural conception.
  • There is a risk of ectopic pregnancy following IVF. When an embryo develops in your Fallopian tube rather than your womb the pregnancy is said to be ectopic. Ectopic pregnancy can cause vaginal bleeding, low pregnancy hormone levels and  miscarriage. Hormone tests and scans are used to detect ectopic pregnancies and you should tell your doctor about any vaginal bleeding or stomach pain.
  • The biggest risk associated with IVF is the risk of multiple births. Please refer to the Risks of Multiple Births information sheet for more information.

Chances of success with ICSI

Fertilisation rates are slightly higher with ICSI compared to IVF as ICSI involves placing a sperm directly inside the egg; however, there is no significant difference in pregnancy rates with ICSI compared to IVF. Female fertility diminishes with age, so if you are using your own eggs, on average, the younger you are the higher your chances of success.

UK average success rates were (2007 figures results, published by HFEA):

  • 3.4% for women aged 43-44
  • 3.1% for women aged 44+

What is involved in ICSI treatment

On the day of egg collection the male partner, if applicable, will be asked to produce a semen sample. If you are using donor sperm, this will be prepared for treatment. A second sample may be needed that day if the first sample is not suitable or sufficient.

Embryo Transfer

ICSI treatment is the same during and after embryo transfer as for routine IVF. For further information please refer to the IVF information page.

Treatment Variation

Occasionally eggs from one patient are split into two groups with one half undergoing conventional IVF and the other half ICSI. The purpose of this is to determine whether or not fertilisation by conventional IVF is possible. We try to avoid this option where possible though as the Human Fertilisation and Embryology Authority (HFEA) Code of Practice only allows embryos from conventional and ICSI cycles to be transferred together in 2% of all ICSI embryo transfers at all licensed clinics. The decision depends upon the number of eggs and quality of sperm available, and the fertilisation outcome in previous treatment cycles, if available.

Congenital bilateral absence of the vas deferens (CBAVD)

Some men are infertile because they do not have the tube (vas deferens) that carries sperm from the testis to the penis. Without this, sperm cannot be released from the penis when a man ejaculates. Men with this problem are more likely to carry a mutation or alteration in the gene associated with cystic fibrosis. You can be a carrier of cystic fibrosis without having CBAVD or have CBAVD with no detectable mutations. If we believe you have CBAVD we will discuss this in detail and suggest testing for mutations in the cystic fibrosis gene. Such mutations are common in certain ethnic groups (about 1 in 25 for Northern European Caucasians) and your partner may also need to be tested for likely inheritance patterns. In the instance that the vas deferens is absent, male patients may undergo sperm aspiration from the epididymis (PESA) or testicle (TESA). For further information about these procedures, please contact your local Spire Fertility site.

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