What to expect during ICSI treatment

Whether you’re comparing IVF and ICSI for the first time or you already know ICSI is likely to be part of your treatment plan, understanding how the process works can bring a sense of clarity and control. Many people begin this journey with questions about what actually happens at each stage, how involved the treatment is, and what they can realistically expect along the way.

This guide breaks down the ICSI pathway into clear, manageable steps, helping you feel informed and prepared as you explore your options or move closer to starting treatment.

ICSI meaning

ICSI stands for Intracytoplasmic Sperm Injection, and it is a form of In Vitro Fertilisation (IVF). ICSI was introduced as an assisted reproduction technology in the early 1990s, with the first births using ICSI reported in 1992.

Today, it is the most popular fertilisation method for all types of IVF treatment, with one UK-based study finding it accounts for 21% to more than 80% of IVF cycles, depending on the clinic.

How does ICSI work?

In standard IVF treatment, each collected egg is placed with thousands of sperm in a petri dish, and fertilisation occurs when a single sperm successfully penetrates that egg. However, in ICSI, a single sperm is chosen and drawn up into a very fine glass needle before being injected directly into the centre of the egg to fertilise it.

Why is ICSI necessary?

ICSI is necessary to overcome male infertility when sperm cannot naturally fertilise an egg. ICSI may be recommended when a male partner has:

• A very low sperm count
• Poor sperm motility
• Poor sperm morphology
• Issues with ejaculation
• A disease, injury or disability that means sperm must be collected surgically from the testicles
• High levels of antibodies against his sperm
• Previous low fertilization with standard IVF

Sometimes, patients will be undergoing an IVF protocol, but on the day of collection, the sperm quality is insufficient for IVF, most likely due to natural variation in semen samples, and the clinic can change the treatment plan to ICSI. This will always be done with patient consent, with the reasons why and any potential extra costs explained. ICSI can also be the next step if you’ve previously had IVF but none, or very few, of the eggs were fertilised.

ICSI success rates

As a fertility treatment, the ICSI procedure is very successful at helping the sperm and the egg to fertilise. Research shows that ICSI results in an average fertilisation rate of 70 in 100.

However, just like with standard IVF, there are still many other factors that influence the likelihood of pregnancy, including:

• Female age
• Embryo quality
• Endometrial function
• Overall health and lifestyle

Overall, success rates for ICSI births tend to be very similar to IVF, so the Human Fertilisation & Embryology Authority (HFEA) don’t publish separate statistics for this fertility treatment.

The ICSI procedure step by step

ICSI treatment is carried out in carefully sequenced steps, each playing a specific role in helping achieve fertilisation and pregnancy. Knowing how these stages connect can give you a clearer sense of what to expect along the way.

Fertility tests and consultation

The first stage of ICSI is for you and (if relevant) your partner to undergo fertility assessments such as blood tests, ultrasound scans, semen analysis, and a medical history review to understand your reproductive health.

A fertility specialist then explains your results, discusses possible causes of infertility, and recommends an appropriate treatment plan, such as ICSI. This stage ensures you have a clear understanding of the process before starting treatment.

Ovarian stimulation

During ovarian stimulation, you take daily hormone injections to encourage your ovaries to grow multiple follicles instead of the single one produced in a natural menstrual cycle.

Throughout this phase, your clinic monitors you with ultrasound scans and sometimes blood tests to track follicle growth and adjust medication doses if needed. Once enough follicles reach the right size, you administer a trigger injection at a precise time to prepare the eggs for collection.

ICSI egg collection

During egg collection for ICSI, you’re given sedation and a thin ultrasound-guided needle is passed through the vaginal wall into each ovary. The procedure typically takes 10–20 minutes and involves a fertility specialist gently drawing out the fluid from each follicle, which contains the eggs.

Afterwards, you rest in recovery for a little while so that your team can check you have had no ill effects from the sedation and that you have passed urine. You’ll be able to go home afterwards, but will need to be transported home by someone else or via taxi.

Sperm collection and preparation

A sperm sample is needed for ICSI. This may be:

• Fresh, having been produced on the same day as egg collection
• Frozen, having been collected and stored in a prior procedure
• Donor sperm that has been previously selected before being shipped to your clinic and stored ready for treatment

If frozen, sperm will need to be thawed and examined to check their quality and ensure their viability for use in treatment. Sperm will be ‘washed’ to separate them from the seminal fluid and other unwanted components like white blood cells and bacteria.

Insemination and fertilisation

The eggs are contained in tubes of follicular fluid. These are given to the embryology lab, who collect the eggs, washes them and incubates them in a special culture medium to keep them safe. They then inject a single sperm into the centre of each egg using a fine glass needle. The morning after the ICSI process, fertilisation is checked to see how many eggs have successfully fertilised and are continuing to develop.

ICSI embryo development

The eggs remain incubated and continue to develop, progressing from single fertilised cells to blastocysts over approximately 5 days:

• Day 2: The zygote divides into a two-cell embryo.
• Day 3: The embryo continues to divide, reaching approximately 8 cells.
• Day 4: The embryo compacts and forms a morula, a ball of 16–32 cells.
• Day 5: The morula develops into a blastocyst.

Embryo transfer

3-5 days after fertilisation, the best embryo will be selected for embryo transfer. This is a short, painless procedure where a fine catheter is inserted into the uterus, and the embryo is gently placed.

You need to have a full bladder for embryo transfer. This helps your fertility specialist see your uterus clearly on the ultrasound scan, which they use to guide the catheter and check that the embryo has been transferred.

After embryo transfer, you’ll be able to go home the same day and resume your usual activities, although many patients like to take it easy for the rest of the day.

Pregnancy test

Two weeks after your embryo transfer, you will have a blood test to measure the level of pregnancy hormone in your blood. This determines whether your ICSI treatment was successful.

ICSI FAQS

ICSI is a well-established, highly successful assisted reproductive technology. However, even if you have a sound understanding of the process, it’s normal to still have some questions before you start your journey.

How long does ICSI IVF treatment take?

A single cycle of ICSI typically takes 4 to 6 weeks from starting ovarian stimulation medications to taking a pregnancy test, although this duration can vary depending on individual circumstances and the protocol used, as well as whether you are having a fresh or frozen embryo transfer. This is because a fresh embryo transfer typically occurs 3-5 days after egg collection, whereas a frozen embryo transfer has a separate timeline, occurring within a different cycle.

How many injections are needed for ICSI treatment?

The number of injections for ICSI treatment varies depending on your protocol and your individual response. If you are placed on what’s known as a ‘long protocol’, the first step is known as down regulation, and this stops your body from producing eggs for a short while. For two to three weeks, you’ll take medicine to suppress your normal menstrual cycle. This may be in the form of a nasal spray or an injection. If you are on a ‘short protocol’, you will not have this down regulation phase.

The ovarian stimulation stage comes next and typically requires a daily hormone injection for between 10 and 15 days. This is then followed by a single ‘trigger’ injection to promote final egg maturation before the ICSI egg retrieval procedure.

Some women are also prescribed progesterone injections after embryo transfer to support implantation and early pregnancy. These will be continued daily until you take a pregnancy test, and if positive, you will likely continue the injections until 8-10 weeks of pregnancy.

How is sperm chosen for ICSI?

As just one sperm is selected to fertilise each egg during the ICSI procedure, the highest quality sperm is chosen. An embryologist will use a high-magnification microscope to visually inspect the sperm sample and identify individual sperm. They will be looking for sperm that have the most normal appearance and good motility. The selected sperm will then be carefully drawn up into a fine glass needle and injected directly into the egg.

How many days of abstinence are required before sperm collection for ICSI?

Before providing a sperm sample for use in ICSI treatment, a man will need to refrain from ejaculation for between 2 and 7 days, according to World Health Organization guidelines. However, this does vary between clinics, and your team will give you specific instructions depending on your treatment plan.

How long after egg retrieval is ICSI done​?

ICSI will be performed on the same day as egg collection. Again, this varies depending on the clinic and their processes, but typically occurs within a 2-6 hour window after the egg collection.

ICSI with Kind iVF

The prospect of beginning fertility treatment can feel exciting and full of hope, but it can also be overwhelming, especially when navigating the physical and emotional demands of ICSI. Having a clinic that understands both sides of that experience makes all the difference.

At Kind iVF, we specialise in advanced treatments such as IVF with ICSI for couples facing sperm-related infertility, with your care delivered by highly skilled embryologists from our partner, London Women’s Clinic.

What’s more, our all-inclusive ICSI package covers everything from medication and monitoring to egg collection, ICSI fertilisation, embryo transfer, and the final pregnancy test, ensuring you’re supported at every step of your journey. To begin your ICSI path to parenthood with Kind iVF, book a consultation.