What is intracytoplasmic sperm injection (ICSI)?

Intracytoplasmic sperm injection (ICSI) is the process of selecting a single sperm and mechanically placing it inside of the egg for fertilization in IVF. ICSI is a complimentary procedure to IVF. In traditional IVF, a large number of sperm are placed next to the egg, and the sperm have to attach and push through the outer layer of the egg themselves.

Intracytoplasmic Sperm Injection

When to consider ICSI

You might want to consider ICSI if you have tried traditional IVF with no or little success, if you are using frozen eggs, or if there are problems related to the following:


    • Too few sperm being produced to conduct artificial insemination intrauterine insemination [IUI] or IVF
    • Sperm that does not move properly (poor motility)
    • Sperm that has difficulty attaching to the egg

  • A blockage in the sperm producer’s reproductive tract that prevents sperm from getting out
  • You have unexplained infertility

What are the steps involved?

For you, the patient, the steps will be the same as the IVF process. The difference is what happens in the laboratory on the day of your egg retrieval.

The ICSI procedure includes the following steps:

Sperm Selection

Embryologists will analyze the sperm. They will choose the most mature and fastest moving sperm out of the sample provided. They will prepare that sperm for fertilization.

Egg Assessment

Once the egg retrieval is complete, the lab will remove the cells surrounding each egg, called the cumulus cells, using a gentle enzyme. This allows the lab to determine how mature the eggs are. Only mature eggs can be used for ICSI.


The lab will then inseminate your mature eggs with the chosen sperm. A single sperm is injected directly into each mature egg. Once injected, the eggs and sperm will be placed back into an incubator. Approximately 18 hours later, the eggs will be checked to see if fertilization has occurred.

Risks associated with ICSI

There are a few risks involved with ICSI. These include medication risks, ovarian hyperstimulation syndrome, procedure risks, cycle cancellation, multiple pregnancy, and other pregnancy risks.

Medication risks

You might feel some bloating and fullness in your lower abdomen, which are normal reactions to the injectable medications. Other side effects include bruising and soreness at the injection site, allergic reaction, gastrointestinal symptoms, headaches, or mood changes. If you experience any reactions, please make sure to discuss these with your doctor.


Ovarian hyperstimulation syndrome (OHSS)

Some individuals develop a large number of follicles and very high hormone levels in response to their ovarian stimulation medications. This over-response to medication is called ovarian hyperstimulation syndrome (OHSS). If the response is severe, fluid (water) can build up in the abdomen and lungs, and blood clots can occur. The fluid may need to be removed with a needle, and hospital admission may be required.


Another rare side effect of ovarian stimulation is torsion, where the ovary twists. This may require surgery.


Procedure risks

Risks may include discomfort during the procedure, bleeding, infection, or puncture of the bowel. Infections are rare but may require antibiotics or rarely surgery. Sedation is another risk, as some people can become too sedated and have breathing or heart rate complications.


Cycle cancellation

In some situations, your ICSI cycle might need to be cancelled before the egg retrieval. If this happens, we will book an appointment with your primary doctor and a portion of your fees will be refunded depending on the treatments that have already occurred.


Multiple pregnancy

The goal of ICSI is to have one healthy baby. However, the risk of multiple pregnancy is higher with ICSI. Risks with multiple pregnancies include miscarriage, premature birth, or long-term health issues such as cerebral palsy. Risks to the person carrying the pregnancy include high blood pressure, diabetes, bleeding, and delivery problems. You may require bed rest or time off work earlier than planned. Please see our Multiple Pregnancy Fact Sheet for more information.


Pregnancy risks

The risks associated with ICSI include the same risks of an IVF cycle. Some studies have shown a slightly higher risk of birth defects in patients undergoing ICSI (7-10%) compared to patients undergoing IVF without ICSI (5-7%).


Other risks associated with ICSI include miscarriage, ectopic pregnancy (where the embryo becomes trapped in a Fallopian tube), high blood pressure, premature birth, C-section, and low birth weight babies.

Pregnancy risks

All pregnancies have a small (3% to 5%) risk of a birth defect. This risk is higher in people experiencing infertility, including those undergoing IVF or ICSI. A vitamin called folic acid can help prevent some types of birth defects called neural tube defects. Folic acid can be found in many foods including dark green leafy vegetables. Most neural tube defects happen in the first four weeks of pregnancy, so it is important to take folic acid before and during pregnancy. For most, the recommended dose is 0.4 mg/day.


Other risks associated with ICSI include miscarriage, ectopic pregnancy (where the embryo becomes trapped in a Fallopian tube), high blood pressure, premature birth, cesarean birth, and low birth weight babies.