Since the world’s first ICSI-conceived baby was born in 1992, this technique has helped thousands of people facing significant male fertility challenges go on to have biological children. If you've been told that ICSI might be recommended as part of your fertility treatment, you may have questions about what the procedure involves and why it's been suggested for your circumstances.
Dr Mandana Master provides clear, individualised guidance through every stage of ICSI treatment, helping you understand your options and feel confident in your care.
ICSI is a specialised laboratory technique used alongside in vitro sperm injection (IVF), during which a single sperm is selected and injected directly into an egg using a fine microneedle. This differs from conventional IVF, where eggs and sperm are placed together in a laboratory dish and fertilisation occurs naturally, with one sperm penetrating the egg without further assistance.
By bypassing the need for sperm to swim to and penetrate the egg on its own, ICSI can achieve fertilisation in situations where conventional IVF would be unlikely to succeed.
ICSI is most commonly recommended for couples and individuals affected by male factor infertility, including:
ICSI may also be recommended in the case of previous poor fertilisation, where a prior conventional IVF cycle resulted in few or no fertilised eggs.
It is also often the most effective method of conceiving with frozen eggs or sperm, as the freezing and thawing process can affect fertilisation through conventional IVF or intrauterine insemination (IUI). Same-sex couples, solo parents, or couples seeking donor conception may be recommended ICSI for this reason.
Dr Mandana will assess your individual circumstances carefully to determine whether ICSI is likely to improve your chances of success, whether as a first-line option or as a next step after trying other less invasive fertility treatments.
ICSI is performed as part of an IVF cycle, following the same initial steps before diverging at the fertilisation stage.
As with conventional IVF, hormonal medication is used to stimulate the ovaries of the female partner to produce multiple eggs, which are then retrieved via a short procedure under sedation.
A sperm sample is prepared and assessed, with the healthiest available sperm selected for injection. In cases of severe male infertility, sperm may be retrieved surgically beforehand. If conceiving with donor sperm, this is thawed.
Using a specialised microscope and a fine glass needle, an embryologist injects a single sperm directly into the centre of each mature egg.
As with conventional IVF, embryos are cultured and monitored over several days, allowing the embryology team to identify the embryo or embryos most suitable for transfer.
A single embryo is transferred into the uterus of the female partner or surrogate using a thin catheter. Any additional healthy embryos can be frozen for future use.
Approximately two weeks after transfer, a blood test is performed to determine whether the ICSI cycle has resulted in a pregnancy.
ICSI success is influenced by many of the same factors as conventional IVF, alongside some specific to the technique itself. Dr Mandana will talk through what these mean for your individual circumstances. Key factors include:
Which is closely tied to the age of the person providing the eggs.
As the genetic integrity of the selected sperm affects embryo development.
Given the precision required to perform the injection technique successfully.
Which remains essential for successful implantation regardless of fertilisation method.
ICSI has been used successfully for over three decades and is considered a safe, well-established procedure. As it is performed alongside IVF, the risks associated with ovarian stimulation and egg retrieval – such as mild bloating or a small risk of ovarian hyperstimulation syndrome (OHSS) – are the same as for conventional IVF.
ICSI itself carries a small additional risk of egg damage during the injection process, though this is uncommon in experienced hands. Some studies have also looked at whether ICSI carries any additional risk of passing on genetic causes of male infertility to male children; Dr Mandana can discuss the current evidence with you in the context of your own circumstances.