Intracytoplasmic sperm injection (ICSI) is a technique used during in vitro fertilization (IVF) where a single sperm is injected directly into the egg for the purpose of fertilization. During conventional IVF, the egg is placed in a culture dish with many sperm and fertilization occurs when one sperm penetrates the egg naturally. According to the American Society for Reproductive Medicine, ICSI is a safe and effective procedure for couples with male factor infertility and can improve the chance of fertilization for couples with poor fertilization in a previous IVF cycle.

Use of ICSI for couples with male factor infertility has increased over time since the technique was introduced in the early 1990s. However, ICSI is also increasingly used in patients without male factor infertility where the procedure has not been shown to improve clinical outcomes. Findings from some but not all studies suggest that ICSI is associated with an increased risk for chromosomal abnormalities, autism, intellectual disabilities, and birth defects compared with conventional IVF. These increased risks may also be due to the effects of subfertility. ICSI also adds to the cost of an IVF cycle, making it more expensive than conventional IVF. Data from CDC’s National ART Surveillance System were used to study national trends in the use of ICSI for couples with and without male factor infertility during 1996-2012. Reproductive outcomes for cycles using conventional IVF and those using ICSI among patients with male factor infertility and among patients with non-male factor infertility during 2008-2012 were also compared. These findings provide important information on the benefits and risks of ICSI.

Assisted reproductive technology – IVF and ICSI

• IVF (in-vitro fertilisation) and ICSI (intracytoplasmic sperm injection) are assisted reproductive treatment (ART) procedures in which eggs are fertilised outside the body.
• IVF and ICSI involve a series of steps taken over several weeks.
• Your personal circumstances and medical history may affect your chance of having a baby with IVF or ICSI.
• When handled by experts, IVF and ICSI are safe, and medical complications are rare.

About IVF and ICSI

The information on this page is a general overview of 2 types of assisted reproductive treatment (ART):

• in-vitro fertilisation (IVF)
• intracytoplasmic sperm injection (ICSI).

What are IVF and ICSI?

IVF and ICSI are forms of assisted reproductive treatment (ART) in which eggs are fertilised with sperm outside the body.

IVF is used for female infertility and unexplained infertility, and ICSI is used when there is a male cause of infertility.

Sometimes ICSI is offered when there is no male cause of infertility, but research shows that this does not increase the chance of having a baby.

The steps involved in IVF and ICSI treatment are:

1. Hormone stimulation – the woman’s ovaries are stimulated with a course of injectable fertility drugs.
2. Egg retrieval – when the eggs are mature, they are retrieved while the woman is under light anaesthetic.
3. Embryo development – when using IVF, sperm from the male partner or a donor are added to the eggs to allow them to be fertilised. When using ICSI, the scientist picks up a single sperm and injects it into each egg using a microscopic needle. The eggs and sperm are then kept in the laboratory for 2 to 5 days (depending on clinic practice) for embryos to develop.
4. Embryo transfer – if the eggs fertilise and embryos develop, one embryo (or sometimes 2) is placed in the woman's uterus. (Sometimes several embryos develop, and they can be frozen for use in later embryo transfer procedures.)
5. Test for clinical pregnancy –2 weeks after the embryo transfer the woman has a blood test to see if the treatment has been successful:
   • If the test is positive, an ultrasound examination is scheduled 2 weeks later to check that the pregnancy is developing normally. (Note: A clinical pregnancy does not guarantee the birth of a baby, as miscarriages can occur.)
   • If the test is negative the woman will have a period and will then need to decide whether to try again. If she has frozen embryos these can be replaced one by one without the need to stimulate the ovaries.
6. Live baby – the birth of a living baby or babies (multiple births are classed as a single live birth).

Risks associated with IVF and ICSI include:

• An excessive response to fertility drugs (ovarian hyperstimulation syndrome)
• Multiple birth (twins and triplets)
• Premature labour and low birth weight
• A small increased risk of birth defects compared with spontaneously-conceived babies
• Caesarean delivery

IVF and ICSI are also psychologically demanding and emotional health effects are common.

Understanding IVF and ICSI success rates

Clinics report success rates in different ways. When comparing clinics’ success rates for IVF and ICSI make sure you compare like with like, or ‘apples with apples’. And, most importantly, you need to consider your own personal circumstances and medical history when you estimate your chance of having a baby with IVF or ICSI.

The woman’s age is the most important factor determining the chance of having a baby with IVF.

Possible health effects of IVF and ICSI

In the hands of experts, IVF and ICSI are safe procedures and medical complications are rare. But, as with all medical procedures, there are some possible health effects to consider for women and men undergoing treatment and for children born as a result of treatment.

What were the reproductive outcomes of ICSI cycles compared with conventional IVF?

• For cycles with a diagnosis of male factor infertility, the likelihood of cycle cancellation between egg retrieval and embryo transfer (a surrogate measure of failed fertilization) was markedly decreased for cycles where ICSI was used, compared with those using conventional IVF, confirming that ICSI increases the chances of fertilization for couples with male factor infertility. There was no difference in cycle cancellation for couples without male factor infertility.
• For cycles with a male factor infertility diagnosis, ICSI use was associated with reduced rates of implantation and multiple births, compared with conventional IVF. However, rates of pregnancy, miscarriage, and live birth were not different for cycles using ICSI versus conventional IVF.
• For cycles without male factor infertility, ICSI use was associated with decreased rates of implantation, pregnancy, live birth, and multiple live births compared with conventional IVF.

More about these findings

• Overall, use of ICSI did not improve reproductive outcomes, regardless of whether male factor infertility was present. This may be due to poorer quality embryos resulting from cycles where ICSI was used because the procedure bypasses natural barriers to fertilization. It is also possible that characteristics of patients who were candidates for ICSI weren’t captured such as poor egg or sperm quality; differences in these factors could explain the findings.
• The primary limitation of our study is that we were unable to directly assess rates of fertilization, where ICSI is expected to be advantageous over conventional IVF.

Sometimes people have embryos in storage that they don’t intend to use. Most commonly this is because they have completed their family, but for some people, health reasons prevent them from using their stored embryos. At the end of the storage time limit, which in Victoria is 5 years, people need to decide what to do with unused embryos.

There are 4 options available:

1. Apply for an extension of storage time.
2. Dispose of the embryos.
3. Let the embryos be used for research.
4. Donate the embryos to an infertile person or couple.

Couples who have frozen embryos that they are not intending to use often find it difficult to decide what to do with them.

• For cycles with male factor infertility, ICSI use increased from 76.3% in 1996 to 93.3% in 2012.
• For cycles without male factor infertility, ICSI use increased from 15.4% in 1996 to 66.9% in 2012.
• Similar increases were found for selected non-male factor infertility indications, including unexplained infertility, maternal age 38 years or older, low oocyte yield, having 2 or more prior assisted reproductive technology cycles and no prior live births, and use of preimplantation genetic testing. ICSI use also increased in the absence of any of these indications, suggesting that other reasons may be influencing the clinical decision to use ICSI.