In Vitro Fertilisation (IVF) Process & Procedures

– What Happens in the Lab?



In Vitro Fertilisation or IVF treatment is not a single procedure, it is a process – one that spans around 28 days and involves a number of steps and procedures, including a 7-day stay for the fertilised eggs or embryos in our modern, sophisticated IVF Laboratory with our team of dedicated, experienced embryology staff.


In this article, we look at what happens in the IVF lab during those crucial days, as well as the people and the state-of-the-art technology that ensures Cape Fertility has one of South Africa’s best IVF labs.

The IVF Process

An IVF treatment cycle is usually around 28 days long and involves a number of steps and procedures.

The short summary below highlights only a few milestones of the full process to place in context the time that the embryos spend in the IVF lab. You can read a full overview of the steps and procedures involved in a typical 28-day IVF plan at Cape Fertility in our article The In Vitro Fertilisation (IVF) Process.

The first day of a typical 28-day IVF cycle is the first day of your period. Two or three days later you will begin to take fertility medications to stimulate egg growth. A week later, you will have your first scan, followed by another scan two days later. On the 12th day, if a third scan confirms that your eggs are ready for retrieval, you will have a trigger injection to prepare you for egg retrieval two days later.

It is on egg retrieval day that the eggs go our IVF lab, where they spend six or seven days before the best quality embryos are selected and transferred to your uterus.

The Days and Processes in the IVF Lab

What happens in the IVF laboratory from Day 0 up until Day 6 is crucial to the success of your IVF treatment.

During this time our team of embryologists collect as much information as possible about your eggs and embryos in order to select the best embryos for your embryo transfer and freezing.

Day 0

Embryologists call egg retrieval day – when your eggs first arrive at the IVF Lab – Day 0. As soon as the eggs arrive, one of our embryologists will screen the retrieved eggs, count them and assess them for maturity and quality. The eggs are individually assessed to make sure that they are at the right maturity stage for fertilization, as immature eggs will not fertilize.

In the morning of Day 0, the sperm that will be used to inseminate the eggs is received from your partner or a donor and processed or “washed” to prepare it for insemination. If the sperm to be used is frozen, the straws or vials containing the sperm will be thawed and processed in the same way.

At Cape Fertility, our laboratory predominantly performs Intracytoplasmic Sperm Injection (ICSI) – a procedure in which sperm is injected individually into mature eggs by an embryologist, using high-powered microscopes, specialised needles and micromanipulation skills.

After ICSI, the eggs are placed in a specially designed culture medium covered with oil that mimic the fluid in the fallopian tubes. It contains the proteins, amino acids and enzymes needed for embryo development. Should you have requested to have your eggs grown in our time-lapse incubator, they will be placed in the EMBRYOSCOPE™.

Day 1

On the next day, the injected eggs are evaluated for fertilisation. This process takes place 16 – 20 hours after ICSI. The presence of two pronuclei (two discs) inside the egg – one from the egg and one from the sperm – indicates normal fertilisation. Fertilised eggs are called zygotes.

At times, the embryologist may not see the presence of pronuclei in the eggs, but that does not always mean that the eggs have not fertilised. After fertilisation check, the dish containing the eggs is placed back into the incubator.

On this day, our embryologist team will send you an update, confirming the number of eggs retrieved the previous day, the number of mature eggs that were injected with sperm and the number of eggs showing normal fertilisation, along with notification of when you will receive the next update for embryo development.

Day 2

The embryologists do not perform embryo evaluations on Day 2, when the fertilised eggs start to divide into cells and become embryos. Most of the embryos will have between two to four cells.

Embryologists are very protective over the growing embryos and will not expose them to temperature variations as this may influence embryo development.

Day 3

Day 3 is in the cleavage stage, when embryos have developed further into six cells, eight cells, multicells and compacting embryos.

On this day, the embryologist will transfer the divided embryos into a new petri dish with media supporting further development of the embryo. The embryos are also graded and images of them captured for further evaluation.

On Day 3, you will receive an update on the developing embryos, confirming how the embryos are growing and when your embryo transfer will take place, usually on Day 5.

Day 4

No evaluation of embryos occurs on Day 4. This is because at the Morula stage, the transition between the cleavage stage embryo and a blastocyst on Day 5, the embryos resemble a cell mass with no distinct features to grade.

Day 5

By Day 5, the embryos will have increased in size and development in what is called the blastocyst stage. During this stage the embryo has certain structures which the embryologist expect to see while performing an assessment. These include the Inner Cell Mass (ICM), which is the foetal component, and the trophectoderm cells (TE), which is the placental component.

The blastocyst will be graded according to the size of the embryo in terms of expansion, the appearance of the ICM and the appearance of the TE cells.

On Day 5, images of the embryos are sent to your fertility specialist who will discuss the embryo results with you and decide with you about the embryo transfer. One or two embryos will be transferred dependent on your individual situation.

The embryologist will then select the best embryo or embryos and load these into a catheter to be transferred into your uterine cavity by your fertility specialist. The remaining good quality blastocysts can be frozen for future use.

Day 6

The remaining embryos are assessed and graded on Day 6 and suitable embryos can be frozen. The lab will only freeze good quality blastocysts as the lower grade embryos will give a poor success rate at thawing.

On Day 6, a final email will be sent to you indicating the number and grade of the embryos transferred and the number and grade of the remaining embryos frozen.

Our Embryologists

Highly qualified, each of our embryologists holds at least a 4-year university degree. Guided by the highest ethical standards, our embryologists are also experienced and work as a team, drawing on their individual experiences and combining their talents to define and establish the finest IVF processes and practices in all areas, including oocyte vitrification, frozen embryo transfer, ICSI and PGS/PGD.

We invite you to meet our embryologists here

Our Facilities

All the procedures in the IVF process are done at our purpose-built premises in Claremont, in the beautiful City of Cape Town. We have a dedicated IVF Procedure Room, a modern and sophisticated IVF lab and a special Embryo Transfer room, all conveniently located adjacent to our Main Reception and Offices.

Our IVF lab is equipped with state-of-the-art equipment such as EMBRYOSCOPE™, providing optimum control of the environment for handling our eggs and embryos and we only use the highest quality products for sperm preparation, egg retrieval and embryo culture.

Your next step

Your first step to undergoing the IVF treatment process is simply to contact us by clicking here… At Cape Fertility, we value each individual patient and we look forward to providing you with our signature individualised and personalised care.