Embryology (Fertility Science)
1. Are my eggs good quality?
It’s understandable to wonder about the quality of your eggs, but egg “quality” isn’t something we can measure directly at the time of collection. What we can assess is whether the eggs are mature and how they look under the microscope, things like size, shape, and other features. If there are any differences from what we typically see, we’ll note them, but eggs can’t be graded in the same way embryos are. The best indication of an egg’s quality is how it performs after fertilisation and as an embryo develops.
2. Is that a good number of eggs?
The number of eggs collected can vary a lot from person to person, and there isn’t a single “right” number. What matters most is not just the total count, but how many eggs are mature, able to fertilise, and go on to develop into healthy embryos. Some people collect only a few eggs and still have an excellent chance of success, while others may collect more but see fewer develop to the blastocyst stage.
Stimulation protocols often aim to produce around 10-12 eggs, but age, ovarian reserve, and individual response mean numbers can range from none to 20 or more. A larger number of eggs doesn’t automatically mean a higher chance of success, because not every egg will fertilise or develop into an embryo suitable for transfer, biopsy, or freezing.
Your care team considers your egg number alongside your age, medical history, and treatment plan to guide the next steps and optimise your chances.
3. (If egg freezing) How many eggs do I need frozen to achieve a pregnancy?
The number of eggs you may need depends on your age, egg quality, and your personal circumstances. In general, younger eggs have a higher chance of leading to a healthy embryo and pregnancy, so fewer may be required. Freezing more eggs simply gives you more opportunities in the future. Not all eggs collected will be mature eggs and suitable for freezing. Your Fertility Specialist can help estimate how many eggs might give you the best chance based on your individual situation. If you visit our website at www.eggfreezingaustralia.com.au there is an egg freezing calculator – Egg freeze calculator. This calculator can help predict your chance of having a baby with the eggs you have frozen.
4. Should I do another egg freeze cycle?
Deciding whether to do another egg freezing cycle is a very personal decision and depends on several factors, including your age, medical history, how many eggs you already have frozen, and your future family plans. Freezing more eggs can increase your chances of having enough healthy embryos when you’re ready to use them, but it also involves considerations like time, cost, and the physical and emotional impact of another cycle.
Your Fertility Specialist is the best person to guide this decision. With the comprehensive view of your personal medical history, they can help you weigh the potential benefits against any risks, so you can determine whether another round is likely to meaningfully improve your chances.
5. Is my fertilisation result good?
Many factors influence fertilisation, including egg maturity, sperm quality, age, and medical history. On average, we expect about 65-75% of eggs to fertilise normally, but some patients do experience having more or fewer.
Not every egg is expected to fertilise as some may be immature, not viable, or fertilise atypically. What matters most is whether a healthy number of eggs are developing into good-quality embryos. Even if the fertilisation rate is lower than expected, it can still yield multiple healthy embryos. Your Fertility Specialist and care team consider fertilisation results together with egg maturity and embryo development to give you the most accurate understanding of your chances moving forward.
6. What was the sperm quality?
On the day of sperm preparation, we assess key factors such as motility (how well the sperm are swimming) and concentration (the number of sperm). These measurements help us understand how likely the sperm are to fertilise eggs, but they don’t tell the whole story. Sperm functionality and their ability to produce good-quality embryos can’t be judged by appearance alone.
For treatments like IVF or IUI, there is a minimum requirement for the sperm count and its motility. If your sperm quality is below this threshold, we will discuss your options with you and your Fertility Specialist. This may include producing another sample or using techniques like ICSI, where a single sperm is injected directly into each egg, to give the best chance of fertilisation. Even if some measurements are lower than average, there are ways we can support fertilisation and embryo development.
7. What is the chance of getting an embryo transferred or frozen from my fertilised eggs?
The chance of a fertilised egg developing into an embryo suitable for transfer or freezing varies between patients. This can depend on individual factors such as egg quality, sperm quality, and age.
At this early stage, the fertilised eggs haven’t started dividing yet, so it’s difficult to give a precise probability. It is common for human embryos to have chromosomal abnormalities, so not every fertilised egg will develop well. Our team look for key milestones that help us understand their potential. The final decision about transfer or freezing is typically made on Day 5 or 6, once we can see which embryos are developing normally.
8. I’m very anxious - can I get an embryo update on day 2, 3, 4, 5?
We understand that waiting can be stressful, and it’s natural to want updates. Daily updates are not usually given because embryo development is dynamic and can change quickly so early information may not accurately reflect the final outcome. Our team will make sure you receive clear updates at the right times and explain what they mean for your treatment.
9. What is the grade of my embryos?
We look at factors such as cell number, symmetry, and overall appearance to assign a grade. While higher-graded embryos do have a better chance of implantation, lower-graded embryos can also result in healthy pregnancies.
The number refers to the embryo’s developmental stage, which is reflected in its size, this goes from a 1 to a 6. A grade 1 is an early blastocyst and a 6 is a fully hatched blastocyst.
1 = cavitating blastocyst
2 = early blastocyst
3 = full size blastocyst
4 = expanded blastocyst
5 = hatching blastocyst
6 = fully hatched blastocyst
Then there are two letters that represent the inner and outer cells of the blastocyst. The inner cells (inner cell mass) will eventually become the baby. The outer cells (trophectoderm) will become the placenta. Both get a grade which is a simply A, B or C
A = good number and quality cells
B = fair number and quality cells
C = low number and quality cells
Early blastocysts and cavitating blastocysts, i.e. 1or 2 grades, are only assigned a developmental stage as the inner and outer cells cannot be fully assessed at that point.
While embryo grading gives us helpful information, it’s only one piece of the picture, many other factors, including genetics, and the uterine environment, also influence each embryo’s potential.
10. What is the chance of pregnancy for each of my frozen embryos?
The chance of pregnancy depends on several factors, including the quality of the embryo, your age, and your individual fertility circumstances. While higher-quality embryos have a better chance of implantation, even embryos with lower grades can result in healthy pregnancies. Because each patient’s situation is unique, your Fertility Specialist will discuss your specific frozen embryos and what the expected chances of success might be for you.
11. Should I do a fresh egg transfer or freeze all my embryos and go straight into another stimulation cycle and make more embryos before I get too old?
This decision depends on several factors, including your age, the number and quality of embryos you currently have, your overall health, and your treatment goals. A fresh transfer may be suitable in some cases, while in others, freezing all embryos and doing another cycle could increase your chances of having more embryos available for future transfers. Your Fertility Specialist and our team can review your results and help you weigh the benefits and risks so you can make the decision that’s right for you.
12. What can the lab do differently to improve my next cycle?
The lab works closely with your Fertility Specialist to optimise every step of your treatment, from egg retrieval to embryo culture and freezing. While every step is guided by best-practice standards, adjustments can sometimes be made based on your previous cycle’s results, such as changes to fertilisation procedure, timing, or techniques used. Your Fertility Specialist and embryology team will review your cycle together and discuss any potential modifications that could help improve your outcomes in the next cycle.
13. How do I transport my embryos to/from another clinic?
Transporting embryos is a highly controlled process. Typically, embryos are kept in a specially designed, temperature-controlled container called a “dry shipper” that maintains the correct conditions during transport. The logistics, including timing, courier arrangements, and paperwork, are coordinated by our lab and the receiving clinic to minimise any risk. You will need to speak with the admin team at both clinics to ensure payment and consent is done before the shipping can be arranged.
14. I want to talk with an embryologist about my frozen embryos/future cycle.
We’re happy to discuss your frozen embryos. Embryologists can explain embryo grading, storage, thawing, and transfer procedures, as well as answer any technical questions you may have, whilst your Fertility Specialist can discuss any plans for future cycles. Please contact our clinic to schedule a time to speak with one of our embryologists or your Fertility Specialist so we can provide detailed information specific to your situation.
15. I want to extend/cancel the storage of my embryos.
You can choose to extend or discontinue the storage of your embryos at any time. Extending storage involves paying the relevant storage fees and signing new consents if applicable. If you decide to cancel storage, the clinic will guide you through your options, which may include embryo donation or disposal. Our team will walk you through the process and answer any questions to ensure your wishes are followed safely and respectfully.
