Embryo grading explained – what do those numbers and letters really mean?

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Here, we break down what embryo grading really represents, how it is used in IVF laboratories, and what it means – and does not mean – for your chances of success.

What is embryo grading?

Embryo grading is a system embryologists use to describe the appearance of an embryo under the microscope at a specific moment in time. It allows us to make informed decisions about which embryos to transfer or freeze, and to communicate clearly within the laboratory team when assessing embryo development.

Importantly, embryo grading is a descriptive tool rather than a guarantee of outcome. IVF laboratories may use slightly different grading systems, which means embryo grades can vary between clinics – even clinics located within the same state – and are not always directly comparable. Understanding what grading does and does not tell us can help you feel more informed and reassured throughout your IVF journey.

Why is so much attention given to embryo grading?

It’s natural to want something tangible to hold onto during IVF, and embryo grades can feel like a clear point of reference. Much like our early educational experiences, receiving a ‘grade’ can feel like an assessment of performance. Many people assume that a higher grade means a better embryo (and therefore a higher chance of success), while a lower grade suggests the opposite.

While this interpretation is understandable, it isn’t entirely accurate. There are many factors involved in embryo development and implantation, and grading alone cannot capture them all.

Embryo grading is not a prediction tool; it is an observation tool. It tells us what an embryo looks like at a particular point in time, not whether it will implant or result in a pregnancy. Every viable embryo, regardless of grade, has the potential to result in a pregnancy.

In our many years of experience in IVF laboratories, we have seen high-grade embryos that did not implant, and lower-grade embryos that went on to become healthy babies. While grading helps us prioritise embryos for transfer or freezing at that moment, it is only one piece of a much larger picture.

When do we grade embryos?

Embryos are grown in the Newlife IVF laboratory for up to six days after fertilisation. By day five or six, embryos ideally reach the blastocyst stage, which marks a critical milestone in development.

At this stage, the embryo has developed into many interacting cells, and for the first time, we can clearly identify three distinct structures:

  • Inner cell mass (ICM): A cluster of cells inside the embryo that will eventually form the baby
  • Trophectoderm (TE): The outer layer of cells that will develop into the placenta, which supports the baby during pregnancy
  • Blastocoel: A fluid-filled cavity that allows the embryo to expand.

A photographic image of a blastocyst (left) positioned next to a graphic representation of a blastocyst (right). The images show the types of cells that go on to become an embryo proper (foetus), including the zona pellucida (shell), cavity, trophectoderm cells (TE) and inner cell mass (ICM).

How does blastocyst grading work?

Blastocyst grading assesses three main features: the stage of expansion, the characteristics of the inner cell mass, and the characteristics of the trophectoderm. Each component is graded separately, as outlined below.

Expansion stage

The expansion stage refers to the size of the blastocyst and how far it has progressed in breaking free from its protective outer shell, known as the zona pellucida. As the blastocyst grows, it needs to thin and eventually break through this shell in a process called hatching.

Expansion is categorised into six stages:

  • Stage 1: Early blastocyst development, where a small fluid cavity is just beginning to form
  • Stage 2: Early expanding blastocyst, with a growing cavity but still relatively small within the shell
  • Stage 3: Expanded blastocyst, where the cavity is larger and the embryo occupies more space, but hatching has not yet begun
  • Stage 4: Fully expanded blastocyst, filling most of the shell, which has thinned significantly
  • Stage 5: Beginning to hatch, with part of the embryo emerging through the shell
  • Stage 6: Fully hatched, where the embryo has completely escaped the zona pellucida and is ready for implantation.

Inner cell mass (ICM) characteristics (A–D)

The inner cell mass is the group of cells that will go on to form the baby. It is graded from A to D based on appearance:

  • A: Many healthy cells that are tightly packed
  • B: Several cells with a slightly looser arrangement
  • C: Few cells that are scattered and less cohesive
  • D: Very few or degenerating cells (considered non-viable).

Trophectoderm characteristics (A–D)

The trophectoderm forms the placenta and is also graded from A to D:

  • A: Many cells are present, forming a strong and cohesive layer
  • B: A moderate number of cells with less uniformity
  • C: Few cells with an irregular appearance
  • D: Very few or degenerating cells (considered non-viable).

Putting it all together

When you see an embryo grade, it is simply a shorthand way of combining these three observations into a single description.

For example, a grade of 5AB means:

  • 5: The blastocyst is beginning to hatch from its outer shell
  • A: The inner cell mass has many tightly arranged cells
  • B: The trophectoderm has a reasonable number of cells forming a mostly cohesive layer (although the layer may not be uniform).

While this grading helps embryologists make informed decisions in the laboratory regarding embryo quality, it’s important to remember that no single grade can determine the outcome of an embryo.

Embryo grades are not fixed and can change over time

Embryo grading provides a snapshot in time. Embryos are dynamic and continue to grow, divide and change as they develop.

For example, an embryo graded early on day five as 2CB may look quite different later the same day, potentially developing into a 4BB embryo. This progression is entirely normal and reflects ongoing development in a viable embryo.

The same principle applies when an embryo is transferred, while others continue developing in the laboratory. An embryo transferred on day five may be graded 3BB, while its siblings reassessed later could receive a seemingly higher grade, like 5AA. This difference is often due simply to timing and additional hours of development – not because the transferred embryo was a poorer option.

At the time of transfer, the chosen embryo was assessed as the best option based on its developmental stage, appearance and timing. Because grading is so closely linked to when an embryo is observed, it is not a reliable way of comparing embryos with one another. Instead, grading is just one part of a broader decision-making process.

You can learn more about this approach in our blog, How we select embryos for transfer.

What grading can (and can’t) tell us

In general, higher embryo grades are associated with higher pregnancy rates, which is why grading remains a useful tool when deciding which embryos to transfer or freeze.

However, embryo grading is not an absolute predictor of outcome. A high-grade embryo does not guarantee a pregnancy, and a lower-grade embryo does not mean a pregnancy will not occur. In practice, we regularly see examples where a high-grade embryo, such as 6AA, does not implant, while a sibling embryo with a lower grade goes on to result in a healthy baby.

Once a pregnancy is established, the embryo’s grade is no longer relevant. It does not predict whether a pregnancy will continue, nor does it reflect the future health of the baby.

If an embryo has been transferred or frozen, it has been deemed viable and has potential. Every viable embryo, regardless of grade, has the capacity to become a baby. For patients with embryos of varying grades in storage, or those who have had a lower-grade embryo transferred, there is every reason to remain hopeful.

Looking beyond letters and numbers

Embryo grading is only one part of how we assess embryo development. In addition to visual grading, we use time-lapse imaging, key developmental milestones, embryologist expertise and AI-powered tools to observe how embryos grow and behave over time.

Together, these approaches provide a better understanding of embryo health and potential, helping us make the most informed decisions for your treatment.

Our guidance for patients

We encourage Newlife IVF patients to focus on the number of viable blastocysts rather than becoming fixated on letters and numbers. An embryo’s potential is far greater than its grade alone.

If an embryologist has transferred or frozen your embryo, the embryo has the capacity to continue developing, and this potential matters far more than a single snapshot assessment.

Interested to learn more about embryo grading or IVF?

If you would like to understand more about embryo grading or IVF treatment, be sure to listen to the embryo optimisation podcast episode. Our team at Newlife IVF is also here to support and guide you throughout your fertility journey – call us on (03) 8080 8933.

How embryos develop – from egg retrieval to blastocyst

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After retrieval, the egg and sperm are combined, and if fertilisation is successful, your embryo spends the first few days growing in the lab under the expert care of our team. This blog will help guide you through these early embryo development steps before transfer or freezing.

Factors affecting embryo development

Embryo development is a complex process that requires a combination of genetic, environmental and physiological factors to progress successfully. To achieve good embryo development, we require:

Healthy egg and sperm

The egg and sperm provide the genetic blueprint for development. Each embryo needs a complete set of 46 chromosomes – 23 from the egg and 23 from the sperm. Some embryos inherit incorrect genetic instructions that can impact embryo development and make it harder for them to divide and grow as expected.

Mitochondrial energy

Embryos need energy to divide and grow, which is provided by mitochondria (tiny energy-producing structures in cells). Poor mitochondrial function can slow or stop embryo development.

Efficient metabolic function

An embryo’s metabolic function provides both energy and the building blocks needed for development. This includes the creation of protein and fats, and the removal of waste products that can be toxic to the embryo. Together, these provide what the embryo needs for growth, cell division and viability.

Timely cell division

Embryos should ideally divide at a regular pace (2-cell, 4-cell, 8-cell, etc.). Uneven and/or delayed division can mean the embryo is of suboptimal quality and may not develop as expected.

Embryonic genome activation

Around Day 3 (see diagram below), embryos start using their own DNA instead of relying on maternal DNA (genetic code from the egg). If this DNA transfer is inadequate, interrupted or missing, this can slow or stop the development of an embryo.

Stable conditions

Embryos need the right temperature, oxygen and pH balance to grow. These factors are carefully assessed and monitored continuously in the laboratory environment.

Difficulties or inaccuracies in any of these processes can affect the way an embryo grows and can impact whether an embryo will reach the blastocyst stage (where it has divided into many cells), making it suitable for transfer or freezing.

Safeguarding your embryos is our highest priority

We understand how important every embryo is to your journey. That’s why we use the most advanced technology and scientifically proven methods to create the ideal environment for embryo development. From carefully performing every procedure to closely monitoring each embryo’s progress, our highly trained embryologists work tirelessly to give each embryo the best possible chance to grow and thrive.

We maintain strict laboratory conditions, including precise temperature, humidity and air quality control to mimic the natural environment as closely as possible. Our team carefully observes each embryo’s development at every stage. Even though not all embryos will reach the blastocyst stage, please know that we do everything in our power to maximise their potential. Your dream of building a family is at the heart of everything we do, and we are committed to providing the best possible care every step of the way.

If you have any questions about embryo development or your fertility journey, please reach out to Newlife IVF. In the meantime, let’s walk through the different stages of embryo development to help you better understand the process.

 

Newlife IVF recognised for excellence again

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Based on figures published by the Herald Sun, sourced from the Federal Government’s Your IVF Success website, Newlife IVF recorded the highest pregnancy rates in Victorian patients under 35 years (per treatment cycle attempt in 2024), achieving a 52% pregnancy success rate (compared with the national average of 41%). Exceptional outcomes were also achieved across older age groups, with pregnancy success rates of 43% for women aged 35–38 years (the national average is 35%) and 31% for women aged 39–42 years (the national average is 25%).

Newlife IVF also excelled in live birth rates across Victoria, achieving an outstanding result of 52% for patients under 35 years (46% is the national average), and 27% for 35–42 year olds (the national average is 24%).1 Notably, since its establishment nearly seven years ago, Newlife IVF has consistently delivered outcomes that surpass the national average.

‘We’re proud of what these results mean for our patients, with pregnancy and birth outcomes that continue to exceed the national average,’ said Dr Nicole Hope, fertility specialist and Medical Director at Newlife IVF. ‘Our approach is built on precision and care at every stage. Our specialists focus on optimising conditions for egg quality and embryo development and implantation, while our embryologists bring exceptional attention to the care of eggs, sperm and embryos. Alongside this, our wider team – including nurses, counsellors, genetic counsellors and administrative staff – provides dedicated support across the many aspects of fertility care that influence wellbeing and outcomes. Together, this depth of expertise creates a strong foundation for patient success.’

Outstanding success rates backed by best-practice patient care

Results like these are not achieved by chance. They reflect a clear and consistent philosophy that has guided Newlife IVF since its inception.

Newlife IVF was built on a shared vision to do things differently. From the beginning, the goal was to create a fertility clinic that puts patients before profits, combining best-practice science with genuinely personalised care and support. Every decision and every advancement have been guided by that principle.

As a clinician-owned and led fertility clinic, Newlife IVF is proud to be an independent specialist fertility centre. This independence enables a more supportive and patient-focused experience than is often possible within large corporate-owned clinics.

‘Our results are a reflection of how we work as a connected team,’ said Dr Tiki Osianlis, Managing Director and Scientific Director at Newlife IVF. ‘Clinical expertise and best scientific practice are essential, but they are only part of the picture. What truly sets our care apart is the way our team collaborates around each patient. We take the time to listen, to understand their circumstances, and to adapt treatment accordingly. That shared commitment across every role allows us to deliver care that is both highly individualised and deeply supportive as patients work towards building their family.’

A patient-first approach to fertility care

Every aspect of care at Newlife IVF is designed with patients in mind. From our state-of-the-art laboratory to the use of advanced scientific tools and techniques, expert-led care is combined with cutting-edge technology to maximise each patient’s chance of success.

At Newlife IVF, we believe everyone deserves the opportunity to build their family. That belief underpins our commitment to making high-quality fertility treatment as accessible as possible. We remain focused on delivering outstanding results alongside compassionate, personalised care, supporting our patients every step of the way as they work towards building the family they dream of.

Appointments with one of our fertility specialists in Melbourne are available for those ready to explore their next steps. Call us on (03) 8080 8933 or book an appointment online.

Footnotes

  1. These measures represent the births per completed egg retrieval cycle. Success rates are based on the number of live births that resulted from the eggs collected from women in 2022 that were fertilised and implanted as embryos in 2022 and 2023. Source: YourIVFsuccess. ↩

Witnessing systems at Newlife IVF

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What is IVF witnessing?

Witnessing in IVF refers to the process of confirming that the correct eggs, sperm and embryos are used for the correct patient at the correct time. It mitigates the risk of mismatched or misidentified samples.  At Newlife IVF, we take this responsibility extremely seriously, which is why we use both electronic and manual methods for accuracy and traceability.

RI Witness – electronic tracking for your peace of mind

Newlife IVF employs the RI Witness electronic witnessing system, which uses Radio Frequency Identification (RFID) technology to track and verify all eggs, sperm and embryos in the laboratory. Each patient is assigned an RFID card and every patient vessel (e.g. tubes, dishes and cryo-vessels) is labelled with a matching RFID tag, all of which are programmed with each patient’s unique IVF code and three points of identification.

How RI Witness works at Newlife IVF:

  • Patient RFID card: you are assigned an RFID card that is linked to your profile. This is used for identification during key procedures, such as egg retrieval and embryo transfer
  • RFID tags on all labware: all test tubes, dishes and cryo-vessels used to hold your biological material are labelled with RFID tags matched to your unique code and profile
  • Real-time monitoring: all lab workstations have RI Witness receivers that detect these tags automatically. The system logs and monitors every sample movement during the procedure in real-time
  • Mismatch protection: if a mismatch ever occurs – for example, if two different tags are brought into an area at the same time – RI Witness triggers an audible and visual alarm, and the procedure is stopped immediately to investigate and correct the issue. To further reduce the risk of mismatches, our embryologists strictly work with the biological materials of only one patient at a time at each workstation.

Cryostorage tracking

All biological material placed into cryostorage is barcoded and tagged using the RI Witness system.

Each cryo-vessel is labelled with:

  • Your full name
  • Date of birth
  • Unique IVF code
  • Date of freezing
  • Barcode is specific to the eggs, sperm or embryos stored inside.

These cold-resistant tags ensure identification is maintained even at ultra-low temperatures. When the material is removed from cryostorage, the barcode is scanned and cross-verified with RFID data and RI Witness, and double-witnessed by embryologists to confirm all points of identification.

Embryologist double-witnessing

In addition to RI Witness, every procedure is manually witnessed by two embryologists. This human double-checking system complements electronic witnessing and adds a layer of human judgement, visual verification and accountability.

Manual witnessing includes:

  • Verifying three patient identifiers (full name, DOB and patient unique IVF code)
  • Cross-referencing all vessel labels, barcodes and RI Witness tags
  • Confirming the procedure that is to take place
  • Checking the freeze dates and, for embryos, specific embryo numbers
  • Confirming the correct sample before and after thawing.

This step is essential when biological material is entering or exiting the laboratory, and before every procedure such as insemination, embryo transfer, embryo biopsy or cryopreservation.

Cryostorage safety – cryo-vessel monitoring and audits

Biological materials such as eggs, sperm and embryos are stored in specially designed devices (cryo-vessels) that are specific for very cold temperatures.  The cryo-vessel is tagged with a special tag that withstands very cold temperatures. The cyro-vessel includes the patient’s name, date of birth, unique IVF code and the date of the freezing, along with a unique barcode that is specific to that patient’s egg, sperm or embryo held within the individual device.

Every sample is:

  • Uniquely identified and traceable
  • Matched at any time using the RI Witness system and barcode
  • Manually verified when moved or thawed.

Regular audits are conducted, comparing all stored material against patient records, to ensure that what is in storage precisely matches what is documented in each individual file and the RI Witness log.

Thawing of stored biological material

When biological material is removed from cryostorage, the barcode is scanned and linked to the patient’s vessel via an RFID tag.  Removal of eggs, sperm or embryos from cryostorage is also witnessed manually by the embryologist performing the procedure and a second embryologist.  Before thawing the biological material, the embryologists will witness the three points of patient identification on the cryotag, the freeze date and, in the case of embryos, the specific embryo number on the cryotag. This is cross-referenced with the vessel the biological material will go into after thawing, and the RI witness system. A mismatch at any point will sound an alarm.

Only once all of these steps have been completed will the thawing of the eggs, sperm or embryos proceed.

Summary of witnessing measures at Newlife IVF:

  • Only one patient’s material is handled at each workstation at any time
  • All vessels and labware are RFID tagged and barcoded
  • The RI Witness system and the embryologist manual double-witnessing are used to confirm all details at every procedure
  • Cryostored material is linked to the patient via a barcode and the RI Witness system.
  • Regular audits verify that frozen material in storage matches patient records and the RI witness system.

Please ask us!

We understand IVF can be a time filled with both hope and uncertainty. Our systems are designed to mitigate risk and ensure your biological material is being managed with the highest levels of care, security and accountability. If you have any questions, please speak to a member of our team. We’re always happy to help you feel supported and informed.

The real cost of egg freezing – a candid conversation between Dr Nicole Hope and Victoria Devine

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Understanding egg freezing and the costs

Victoria Devine aims to make finance easier in every area of life, including fertility care. To do this, she strongly advocates that you take the time to do your research. Whether it be a new sweater, a first home or your future fertility – it pays to educate yourself first.

Victoria sat down with Dr Hope and asked her all about egg freezing. With a straightforward clarity that comes from her decades of fertility experience, Dr Hope outlined the egg freezing and IVF processes, and the differences between the two. She also explained how fertility care is timed to match the natural rhythms of your body. For this reason, a lot of fertility treatments are timed around your menstrual cycle.

‘The body has it all worked out and everything we do is actually trying to mimic or replicate what happens in the body,’ said Dr Hope.

Having covered the fundamentals, Victoria and Dr Hope then dived into the costs of egg freezing and IVF, as well as who is eligible for Medicare deductions to their fertility treatment. Dr Hope also discussed some of the patient financing options available to help people manage the costs of fertility care more comfortably.

Cutting out hidden fees at Newlife IVF

When it comes to any major expenses, Victoria recommends that it can be helpful to budget for both the known costs and any additional expenses that may come your way. In the case of egg freezing – depending on the healthcare provider you choose – you may have costs tacked on outside of the initial quote.

This is why at Newlife IVF, transparency with patients is a priority. It is rare for a patient to receive an unexpected or additional cost – and if there is a medical need for one, this will always be discussed beforehand.

‘People shouldn’t be getting too many extra costs outside what they are quoted,’ said Dr Hope.

Dr Hope also explained that all Newlife IVF patients receive an appointment with a member of the finance team before any treatment is started. This appointment helps people understand the costs of treatments and services, and the financing options available, which can help them make informed decisions about whether the treatment/service is right for them.

Infertility is more common than you may think

To complement Dr Hope’s fertility guidance, Victoria shared her own pregnancy experience, as well as the fertility journeys of some of her friends. It quickly became clear how varied fertility journeys can be and that there is no one-size-fits-all for family planning. This led Victoria to ask if there are any factors that can affect someone’s fertility.

Dr Hope explained that the quality of a woman’s eggs is one of the main contributors to their chances of having a baby. She added that although egg quality is affected by many factors, age is often the most crucial.

‘For women, the single biggest thing that predicts when we can get pregnant is our age,’ said Dr Hope.

Drawing on her proactive approach to fertility treatment, Dr Hope also talked through what people can do to improve their egg quality at any age.

A brief background about the webinar presenters

Victoria Devine is a multi-award-winning financial advisor, business owner, podcaster and author. She hosts the popular podcasts She’s on the Money and The Property Playbook, and is the CEO of Zella, a financial services company. Through all her ventures, Victoria aims to transform the way millennials think about money to make their financial dreams achievable.

Dr Nicole Hope is a highly experienced fertility specialist and the Medical Director of Newlife IVF. She also holds an advanced Certificate in Reproductive Endocrinology and Infertility (CREI). This is the highest level of qualification you can have in fertility care and less than 100 Australian fertility specialists have it! Above all, Dr Hope is passionate about helping her patients start or grow their families, and she prioritises the importance of providing the right information and support at each step of fertility care.

Learn more about the financial side of egg freezing

Watch the webinar for a full breakdown of egg freezing, the costs and the financing options available.

How does ICSI increase IVF success?

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The traditional IVF approach is to allow this meeting to take place ‘naturally’, albeit in a laboratory dish: the woman’s egg is placed in a special culture medium with a prepared semen sample containing thousands of sperm. The fittest sperm fertilises the egg, mimicking what would normally happen in the woman’s reproductive tract.

As its name suggests, ICSI is far more precise. Rather than leaving the egg and sperm to meet on their own accord in a laboratory dish, this technique allows us to directly inject a single sperm into a woman’s egg, thereby overcoming any issues that may be getting in the way of a sperm and an egg meeting and coming together naturally. Here, we consider some of the reasons why ICSI may be considered during IVF and what specific fertility problems it can help overcome.

Who is ICSI suitable for?

When a couple is experiencing difficulties getting pregnant, it can be easy to focus solely on the woman’s fertility. However, a male factor contributes to infertility in approximately 40% of couples who fail to conceive.1 ‘Male factor infertility’ typically involves an alteration in the number, shape and/or movement of the man’s sperm, all of which can affect the sperm’s ability to fertilise an egg the natural way. ICSI is most commonly used to help overcome these types of sperm-related issues.

ICSI may also sometimes be offered if a woman has very few eggs available (e.g. due to age). In this case, ICSI is used to increase the chances of successful fertilisation, thereby lowering the risk that the woman runs out of eggs before she achieves a successful pregnancy through IVF.

ICSI may also be recommended if one or more previous standard IVF cycles were not successful due to failed fertilisation, or if the reason for cycle failure is unclear but a sperm-related issue is suspected despite a normal semen analysis.2

A checklist for fertile sperm

If your doctor suspects male factor infertility could be affecting your chances of pregnancy, they will usually suggest a semen (sperm) analysis. This is the main method used to test male fertility. During the analysis, a number of different factors that could be affecting your ability to conceive naturally are studied, including:

  • The volume of semen, which needs to be sufficient to transport sperm into the female reproductive tract
  • The sperm concentration and total sperm count, which affect the likelihood that enough sperm will reach the egg in order for one to fertilise it
  • The physical shape of the sperm, as abnormally shaped sperm can have difficulty swimming to the egg or penetrating the egg’s outer layer
  • The motility of the sperm (i.e. how well it can swim) – if large numbers of sperm in the sample are ‘weak swimmers’, then a natural pregnancy will be more difficult to achieve.

Your specialist might also recommend additional testing for:

  • Sperm DNA damage or fragmentation: sperm with damaged or fragmented DNA have a reduced chance of fertilising an egg
  • Sperm antibodies, which if present, can attack and impair sperm function.

Depending on your results, your doctor may then order follow-up tests to make sure the results are accurate and/or to see if anything else is preventing the semen from doing its job.

Once the tests are complete, your specialist will discuss your results with you and explain what your options are, including whether ICSI is likely to increase your chances of successful fertilisation and the overall success of your IVF treatment cycle.

Success rates with ICSI

Because of ICSI, many previously infertile men now have a good chance of fertilising eggs with their sperm. With some couples, pregnancy rates as high as 45% have been achieved with ICSI.3 However, rates this high are not always possible because of other factors, including age and egg quality.

The fertilisation of an egg and its subsequent development into a growing embryo is a complicated process, and there are many reasons why IVF may not be successful, even with the assistance of ICSI. To aid our success rates at Newlife IVF, we:

  1. Ensure an egg is suitable for fertilisation prior to ICSI: Using polarised light microscopy, we assess a structure inside the eggs called a ‘spindle’. We call this ‘egg spindle visualisation’. This allows us to identify if an egg is at a certain stage of development (called metaphase II) and therefore, in optimal condition for fertilisation via ICSI.
  2. Select the healthiest-looking sperm for ICSI: If the genetic information in the sperm has been damaged, or if the sperm is unable to use its DNA correctly, then there is a risk that development of the embryo will fail, even if it has been successfully fertilised via ICSI.4 A number of factors can increase this risk, such as smoking and older age.5,6 It’s not currently possible to know if the sperm we choose for ICSI is completely free of genetic defects. However, by using an advanced imaging system with an extremely high-powered microscope, we are able to study the structure of individual sperm, helping us to select the optimum sperm to inject into an egg. Sometimes, we may also use another technique, called intracytoplasmic morphologically selected sperm injection (IMSI), to help us pick out a healthier sperm based on its shape. A DNA test can also provide us with more details about sperm quality.
  3. Assess the best position to inject the sperm into the egg: Our extremely high-powered microscope also allows us to very precisely inject the selected sperm into the egg, such that we avoid an important structure inside the egg called the spindle. Research has shown that injecting eggs away from the spindle results in higher fertilisation rates and better embryo quality.

Are there any risks with ICSI?

As with any medical procedure, ICSI carries both potential benefits and risks. While complications are uncommon, some risks specific to ICSI include:

  • Damage to the woman’s egg: Though the risk is low, the process of preparing the egg and inserting the needle can cause structural damage to the egg
  • Genetic inheritance of male infertility: If ICSI is used due to a genetic issue on the Y chromosome, there’s a possibility that a male child could inherit the same condition.

Your fertility specialist will only recommend ICSI if the potential benefits outweigh the risks for your individual situation. It’s important to discuss these factors in the context of your personal circumstances.

What is the cost of ICSI?

ICSI is offered as part of an IVF cycle. Please visit our IVF fees page for more detailed information about the costs involved.

Still have questions?

If you are concerned about the possibility of male factor infertility or would like more information about the role of ICSI in an IVF treatment cycle, you can make an appointment with one of our fertility specialists by calling Newlife IVF on (03) 8080 8933. You can also book online via our appointments page.

References

  1. Agerwal A et al. Reprod Biol and Endocrinol. 2015;13:37–46. ↩
  2. Palermo GD et al. Sem Reprod Med. 2015;33:92–102. ↩
  3. Palermo GD et al. Sem Reprod Med. 2009;27:191–201. ↩
  4. Colaco S & Sakkas D. J Assisst Reprod Genet. 2018;35:1953–1968. ↩
  5. García-Ferreyra J et al. Clin Med Insights. Rep Health 2015;9:21–27. ↩
  6. Zini A & Sigman M. J Androl 2009;30:219–229. ↩

Giving embryo transfer the best chance of success

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As science and technology have progressed, so too have the techniques we can use during embryo transfer to increase the chances of a successful pregnancy. Below we outline the specific techniques we use at Newlife IVF to facilitate success during this part of the IVF cycle.

1. Growing and selecting the best embryo

During IVF, your eggs, sperm, and later embryos, are kept in an incubator. An incubator is a bit like an oven. It maintains a stable environment (including an even temperature), which helps the embryos to grow and develop.

As your embryos grow in the incubator, we observe them very carefully. In the past, this meant repeatedly opening the incubator at regular intervals to get ‘snapshots’ of their growth – but this also meant that we were constantly disturbing the embryos as they developed.

More recently, advances in technology have led to the development of a special type of incubator called the EmbryoScope time-lapse system. The EmbryoScope has a built-in camera and high-powered microscope, which enables us to automatically capture images of your growing embryos every 10 minutes. Essentially, this means we no longer have to keep opening the ‘oven door’, allowing us to closely monitor the development of your embryos without disturbing them.

The benefits of this are two-fold:

  1. We ensure a stable environment for embryo growth, which contributes to embryo quality, and;
  2. We get a more complete picture of embryo quality, enabling us to select the best embryo for transfer.

In most cases, we will select embryos that are at the ‘blastocyst’ stage of development (around 5 days old). This is roughly the same time that an embryo would normally be in the uterus after a natural conception. Transferring the embryo at this stage (instead of the earlier ‘cleavage’ stage around day 2–4) means the embryo is more mature and has already demonstrated its potential for strong growth. Blastocyst transfer may also reduce the risk of the embryo being expelled from the mother due to altered levels of hormones that can occur after the egg freezing process.

The other benefit of waiting until embryos have reached the day 5–6 cell stage is that we can test them for chromosomal or specific genetic defects prior to transfer using preimplantation genetic testing. These tests are not recommended for everybody but may be advised if you are older, have experienced recurrent miscarriage or multiple failed IVF cycles. In this case, our aim is to screen out any embryos with genetic anomalies that are unlikely to result in an ongoing healthy pregnancy, so that the embryo with the best potential for development can be placed in the womb.

At Newlife IVF, we routinely use the EmbryoScope time-lapse system for all IVF procedures, as part of our standard of care. Patients do not pay more for this technology. It is included in our standard cycle fees.

2. Deciding the optimum number of embryos to transfer

In the past, it was common practice to place two or more embryos in the womb at the same time, with the aim of increasing the chance of success. However, this practice has fallen out of favour due to the likelihood of a multiple pregnancy (e.g. twins or triplets). While this may seem like an ideal way to complete your family in one go, multiple pregnancies actually carry an increased risk of miscarriage and other complications. For this reason, our preferred practice at Newlife IVF is to transfer a single, high-quality embryo. That’s why we put a lot of effort into selecting the right embryo to transfer.

3. Guiding and protecting the embryo during transfer

The way an embryo is transferred into the womb is also critical to its success. We use a thin, flexible tube, called a soft catheter, to guide the embryo and protect it during its journey from the incubator to the womb.

For the best possible odds of an ongoing pregnancy, the embryo also needs to be placed in the correct location within the womb. Every woman’s uterus can vary in shape, so we may sometimes conduct a ‘mock embryo transfer’ before the actual procedure to determine the location and transfer technique that will give the best chance of success.

During the transfer, we use ultrasound imaging (the same technology used to view a baby in the womb) to provide us with real-time information about the catheter’s location, enabling highly accurate placement of the embryo in the womb.

4. Helping the embryo to implant in the wall of the womb

Once the embryo has been placed in your womb, it must attach to the wall of the uterus in a process called implantation before it becomes a viable pregnancy.

To improve the likelihood that the embryo implants, we place the embryo in a special substance called EmbryoGlue before we transfer it. EmbryoGlue was developed following the discovery that certain compounds that occur naturally in the body may help the embryo attach to the wall of the uterus.

A major component of EmbryoGlue, hyaluronan, is normally found in the uterus and has chemical properties that increase cell viscosity. This is thought to assist the embryo to attach to the wall of the womb, increasing the chances of implantation and a successful pregnancy.

Fresh versus frozen embryo transfers

Using fresh or frozen embryos affects the timing of your embryo transfer. In a fresh transfer, the embryo is transferred 3–5 days after egg collection and fertilisation (once it has reached the blastocyst stage). In a frozen transfer, previously frozen embryos are thawed and transferred into the uterus at a later date.

While many assume that a fresh embryo transfer is faster or more effective, this is not always true. During IVF, hormone levels can rise significantly, which may prime the uterus to become receptive to implantation before the embryo has reached the necessary blastocyst stage. The use of frozen embryos allows us to avoid this issue. Freezing embryos shortly after they reach the blastocyst stage provides additional time for hormone levels to return to their normal cyclical rhythm, allowing us to align the window of uterine receptivity with the embryo transfer.

Frozen embryo transfer may also be more suited to patients who have high progesterone levels at the time of egg collection, those with PCOS, or anyone undergoing genetic testing of embryos, which requires additional time. Comparably, fresh transfer may be suitable for patients with a limited number of embryos or where time-to-pregnancy is a consideration.

At Newlife IVF, your fertility specialist will help determine the most suitable approach based on your unique circumstances to improve your chances of a successful embryo transfer.

What to expect on the day of your embryo transfer

An embryo transfer is a straightforward procedure. The experience is comparable to a Pap smear, and an anaesthetic is not needed. Most women can return to their usual activities shortly after the procedure.

We aim to optimise every step in the treatment cycle

By employing advanced scientific techniques like these at every step in the IVF cycle, we aim to give our patients a better chance of achieving a successful pregnancy sooner.

If you would like advice specific to your circumstances or a second opinion, you can make an appointment with one of our fertility specialists by calling Newlife IVF on (03) 8080 8933 or by booking online. This appointment does not need to be about IVF specifically – there are many different ways we can assist with conception depending on your fertility needs.

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