ICSI vs. IVF: Understanding the key differences

• What are the differences between IVF and ICSI treatment?
• When is IVF recommended?
• When is ICSI recommended?
• Risks and considerations of IVF and ICSI
• How to choose between IVF and ICSI
• Is ICSI better than IVF?
• What else should you know about ICSI and IVF?
• Getting IVF or ICSI with donor sperm

IVF (In Vitro Fertilisation) is a common fertility treatment that involves mixing sperm and eggs in a laboratory environment, then transferring the resulting embryo(s) to the recipient’s uterus to develop further. ICSI (Intracytoplasmic Sperm Injection) is a specific IVF technique in which sperm is injected directly into the egg. The main difference between the two is how the sperm is combined with the egg in the lab.

Fertilisation method

IVF and ICSI differ in how the sperm fertilise the egg. In IVF, eggs and sperm are combined in a laboratory dish and the sperm still has to swim to and penetrate the egg, allowing natural selection to determine fertilisation. In contrast, ICSI involves selecting a single sperm cell and injecting it directly into the egg. This means the sperm receives more assistance, making it well-suited to situations where sperm motility or other male-factor challenges are a concern.

Indications for IVF or ICSI

IVF is usually recommended for individuals with different fertility challenges or advanced maternal age. ICSI is particularly beneficial for couples experiencing fertility challenges related to male fertility or when previous IVF attempts have been unsuccessful.

Success rates of ICSI vs. IVF

IVF has an approximate success rate of 32-40% per cycle for aspiring mothers under 35. For mothers over 35, the success rate per cycle is 5-30%. 

ICSI can improve the chance of fertilisation when male-factor fertility challenges are present, but it does not automatically improve the chance of pregnancy compared with IVF. 

In instances where male-factor fertility is not a concern, IVF and ICSI have similar success rates. The key factors influencing IVF success rates are age, egg quality, sperm quality, medical history and the quality. 

IVF vs. ICSI costs

ICSI is usually more expensive than conventional IVF, though this can depend on how many cycles are required. For instance, a single successful ICSI cycle is likely to cost less than several IVF treatment cycles. In the UK, a single IVF cycle can cost between £3,000 and £10,000. ICSI typically increases costs by £1,000 to £2,000.

IVF is typically recommended when:

• You are experiencing fertility challenges, such as blocked fallopian tubes, PCOS or endometriosis.
• You have a low ovarian reserve or are of advanced maternal age.
• You are in a same-sex female relationship.
• You are an aspiring solo mum.
• You are starting a family with the help of donor sperm or eggs.

ICSI is typically recommended when:

• Male-factor fertility challenges, such as low sperm count, reduced sperm motility and abnormal sperm shape are a concern.
• You have had previous unsuccessful IVF treatments.

Both IVF and ICSI are safe and well-established fertility treatments. However, there are some risks to consider. These include:

• Hyperstimulation syndrome (OHSS) - a response to fertility medications that can result in enlargement of the ovaries and abdominal pain.
• Multiple pregnancy - if more than one embryo is transferred to maximise the chances of a successful transfer, there is the possibility that more than one embryo will implant.
• Ectopic pregnancy - as the embryo is free-floating in the uterus for several days before implanting, there is a slightly higher chance of ectopic pregnancy. However, the likelihood of a post-IVF ectopic pregnancy is still less than 5%.
• Egg retrieval complications - such as bleeding, infection or internal injuries. 

In ICSI specifically, there is also a very small risk that an egg may be damaged during the sperm injection process. Your fertility team will discuss these risks with you and explain the steps taken to minimise them before treatment begins.

Your decision should be based on discussions with your fertility specialist and take your personal circumstances and preferences into consideration. In most cases, your fertility clinic will recommend a particular treatment based on their initial assessment and conversations with you. 

If you feel strongly about a particular aspect of your treatment, make sure you talk to your fertility specialist about it. They will provide all the relevant information and guidance so you can make an informed decision about the best path forward for your family.

No, ICSI should not be considered “better” than IVF. Instead, it is better suited to certain situations and health contexts, such as those instances where male-factor fertility challenges are present. In other cases, IVF may be the preferred option because it is less complex, more affordable and has a similar success rate. 

The best treatment for you is the one that meets your unique needs and reflects your personal circumstances.

What is IVF?

IVF is a common fertility treatment that involves laboratory-based fertilisation of eggs with partner or donor sperm. The resulting embryos are monitored in the lab for several days, and one or more is selected for transfer into the uterus.

IVF treatment typically involves the following steps:

• Hormone therapy to produce multiple eggs.
• Egg retrieval from the ovaries when the eggs are ready.
• Fertilisation of eggs in a laboratory.
• Monitoring fertilised eggs and embryo development.
• Selecting and placing one or more embryos into the uterus.

What is ICSI?

ICSI is a specific IVF technique that involves injecting a single sperm directly into an egg to facilitate fertilisation. This contrasts with conventional IVF, in which sperm are combined with the eggs in a petri dish and still have to reach and penetrate the egg to fertilise it.

ICSI treatment typically involves the following steps:

• Hormone therapy to stimulate egg production.
• Egg retrieval when the eggs are ready.
• Injection of a single sperm cell into an egg. 
• Monitoring fertilisation and embryo development.
• Embryo transfer to the uterus.

Is ICSI the same as IVF?

No, ICSI is a type of IVF treatment, but differs from conventional IVF in several ways. The most important distinction is that in ICSI a single sperm cell is injected directly into an egg to facilitate fertilisation in the lab. In conventional IVF, sperm and eggs are combined in a petri dish, and the sperm still has to reach and penetrate the egg.

Is ICSI more expensive than IVF?

Yes, a single ICSI cycle is more expensive than a single IVF cycle. However, overall costs depend on the number of treatment cycles required. For instance, a single successful ICSI cycle is likely to be less expensive than IVF treatment that requires multiple cycles. 

Can ICSI be used with donor sperm?

Yes, ICSI can be used with both donor and partner sperm.

Donor sperm is regularly used in IVF and ICSI and can play a role in determining which treatment is most suitable. Typically, your clinic decides whether IVF or ICSI is appropriate based on how the sperm has been prepared and stored, previous fertilisation outcomes, and their own clinical protocols.

If you do not have a clinic yet or need guidance in navigating your fertility journey, we are always here to help you. A fertility consultation can help assess your unique situation, answer your questions and provide tailored recommendations based on your needs.