IVF & ICSI – Laboratory Fertilisation Methods
What Are IVF and ICSI?
In Vitro Fertilisation (IVF) and Intracytoplasmic Sperm Injection (ICSI) are the two main methods we use in the lab to fertilise your eggs after egg collection. They are both part of an IVF treatment cycle and are performed in our embryology lab after the eggs and sperm have been prepared.
What’s the Difference Between IVF and ICSI? Which One Is Right for Me?
Both IVF and ICSI aim to achieve fertilisation — the joining of the egg and sperm to form an embryo. The main difference lies in how fertilisation happens.
IVF (In Vitro Fertilisation)
In IVF, eggs and sperm are placed together in a dish and left overnight. The sperm are expected to swim to the egg and fertilise it naturally.
IVF may be recommended when:
- Sperm parameters (count, motility, morphology) are normal.
- There is no male infertility.
- Fertilisation occurred normally in previous IVF cycles.
This method allows for natural sperm selection, making it slightly more physiologically aligned.
ICSI (Intracytoplasmic Sperm Injection)
In ICSI, an Embryologist selects a single sperm and injects it directly into each mature egg using a fine needle under a microscope.
ICSI may be recommended when:
- There is male factor infertility (low count, motility, or abnormal morphology).
- The sperm has been frozen or surgically retrieved (e.g., PESA, TESA).
- There was poor fertilisation in a previous IVF cycle.
- The eggs will undergo genetic testing for Monogenic Diseases (PGT-M).
- The sample contains very few viable sperm.
Sometimes, your doctor and Embryologists may recommend using both IVF and ICSI on separate groups of eggs in the same cycle, depending on your specific situation.
What Happens in the Lab?
Once the eggs have been collected
- In IVF, we mix the eggs with sperm in a petri dish and place them in an incubator for 16–18 hours.
- In ICSI, we inject one selected sperm directly into each mature egg.
Please note that only mature eggs can be fertilized. The next morning, we check to see if fertilisation has occurred.
How Do We Know If Fertilisation Was Successful?
If fertilisation is successful, we see two pronuclei (2PN) under the microscope – one from the egg and one from the sperm. This is a normally fertilised egg and is called a zygote.
Why Might Some Eggs Not Fertilise?
Not every egg fertilises, even with ICSI. In these cases we see 0PN (no pronuclei): Fertilisation did not visibly occur.
Common reasons include
- There was no binding between the eggs and the sperm after conventional IVF insemination.
- The egg or sperm was not mature.
Common reasons include
- In rare cases, the injection process in ICSI may damage the egg.
- The molecular “activation” between sperm and egg did not happen.
We may also see abnormal fertilisation, explained below.
What Is Abnormal Fertilisation?
What Is Abnormal Fertilisation?
At Almond Blossoms, we use the highest-quality equipment and perform all procedures under strict quality control to minimise risks and optimise outcomes.
Our Commitment to You
Choosing IVF or ICSI is not something you have to decide on your own.
Our medical and embryology team will:
- Carefully evaluate your individual case.
- Recommend the most appropriate method for fertilisation.
- Support you through every step, from egg collection to embryo transfer.
We are here to help you feel informed, confident, and cared for throughout your fertility journey.