Intracytoplasmic Morphologically Selected Sperm Injection (IMSI)

IMSI with IVF is an advanced fertility treatment which may be recommended to you if you have previously experienced a miscarriage or unsuccessful implantation.

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CGI closeup of IVF treatment and sperm being injected into the egg.

What Is IMSI in IVF Treatment?

Intracytoplasmic Morphologically Selected Sperm Injection (IMSI) with IVF is an advanced technique used in fertility treatment where powerful magnification is used to select the sperm with the best size and shape to inject into the egg.

There is some limited evidence to suggest that by selecting the sperm with the best morphology, pregnancy rates might be improved and miscarriage rates are reduced. However, as research continues, there is not yet conclusive evidence as to the benefits of IMSI during the IVF process.

IMSI can be used when sperm quality or morphology is sub-optimal, allowing the embryologist to select the best sperm with which to fertilise the egg. IMSI is similar to Intracytoplasmic Sperm Injection (ICSI); the latter is often combined with Preimplantation Genetic Diagnosis (PGD) or testing for aneuploidy (screening for numerical chromosomal abnormalities).

As IMSI is classed as an Add On by the HFEA, it will be recommended if deemed to reduce the chances of miscarriage or implantation failure.

Semen Culture Test

Our Outstanding Success Rates

IVF with IMSI/PIMSI Live Birth Rates, Per Embryo Transferred, 2021

Live Birth Rate per embryo transferred in under 35s



Live Birth Rate per embryo transferred all ages average



Live Birth Rates per Embryo Transferred by age group


Complete List of Success Rates

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Talk To A Specialist
Almost every treatment journey begins with an initial consultation. At The Centre for Reproductive and Genetic Health (CRGH), you will meet with a fertility consultant of your choice for a 60-minute video call. They will take a detailed medical history and, based on that information, talk you through your treatment options and answer any questions you might have. This is also when you can ask if IVF with Intracytoplasmic Morphologically Selected Sperm Injection might be suitable for you.
Our consultants are experts at understanding your previous medical and fertility history, as well as your goals for treatment, and will be able to provide options based on your unique fertility journey.
Young vibrant women smiling at the camera.

Frequently Asked Questions

The process of IVF with IMSI

How long does IVF with Intracytoplasmic Morphologically Selected Sperm Injection take?

Using IMSI doesn’t usually impact the typical timeline for a cycle of IVF treatment, which usually takes around six weeks. This estimate can vary for different individuals, and is often governed by menstrual cycles.

Is IVF with IMSI suitable for everyone?

IVF with IMSI is considered an Add On, and therefore is only offered to those for whom it is deemed relevant. This can include those who have previously had an unsuccessful implantation or miscarriage.

Is IVF with IMSI safe?

IVF with IMSI comes with certain risks that are still being researched, and should be taken into consideration. For example, there is a very small risk that the egg may be damaged during the injection process.
Your consultant will explain these risks and the measures we take to avoid them. You can read more about the risks below, or visit the HFEA website which explains the risks for IVF and all other fertility treatments available in the UK.

Can you use donated sperm or eggs for IVF with IMSI?

Yes, you can use donated egg or sperm in IVF with IMSI. Our specialist team can help you find appropriate donated gametes.
You can learn more about IVF with donated eggs and IVF with donated sperm on our website.

Can you pause during the IVF with IMSI process?

Yes, with IVF you are generally able to “pause” at certain points in the process, and using an Intracytoplasmic Morphologically Selected Sperm Injection does not affect this. This can be helpful for those who have other commitments.
Speak to your consultant for more information on how to schedule your treatment.

How much does IVF with IMSI cost?

We tailor your treatment at every stage to ensure you have the best possible chance of success. Treatment costs will vary depending on your individual needs, particularly when it comes to medication, so prior to starting treatment, our finance team will provide you with an itemised costing of your unique treatment plan.

What Are Add Ons?

Learn more about Add Ons

The HFEA defines Add Ons as “optional treatments” where the evidence for their effectiveness is “missing or not very reliable”. As part of our continuous efforts to develop and prove new techniques and treatments, there is not always enough evidence to say without doubt that a particular treatment type is beneficial for all patients.

For this reason, we only offer certain Add Ons to patients for whom we believe that treatment to be beneficial. IMSI is considered a Grey Add On by the HFEA.

Risks of IVF with IMSI

Go to HFEA website
There is a small risk of the egg being damaged during the injection process, as well as the usual risks associated with IVF. These risks include:
• Ovarian hyperstimulation syndrome (OHSS)
• Multiple births (twins or triplets)
• Ectopic pregnancy
Your consultant will discuss these risks, and how we avoid them, during your consultation.
IMSI is deemed an Add On by the HFEA; you can learn more about the risks associated with all fertility treatment available in the UK on the HFEA website.