I do have some personal experience with embryos, so I can provide some explanation of what embryo grading means and what it takes for an embryo to receive a good grade. This is often an area for many couples that can be quite a minefield and areas we get hung up on in getting a good grade quality, but in truth most clinics can be different in their approach and how embryos' qualities are graded.
Embryo grading is a system used by fertility clinics and embryologists to evaluate the quality and potential of embryos during the IVF process. The grading system can vary between clinics as I've said, but it typically involves assessing the appearance of the embryo under a microscope based on several criteria.
Embryos are typically evaluated on two main factors: morphology and development stage. Morphology refers to the physical appearance of the embryo, including the number and quality of cells, the shape and size of the embryo, and the presence of any abnormalities or fragmentation. Development stage refers to how far along the embryo is in its development, typically measured by the number of days since fertilisation.
In general, the higher the quality of the embryo, the more likely it is to result in a successful pregnancy. Embryo grading is therefore an important tool for fertility clinics to help determine which embryos to transfer and which to freeze for future use.
The grading typically involves assigning a letter or number grade to the embryo based on its appearance and development stage. As this system can vary between clinics, it is important perhaps to understand some common grading systems, which include the following:
- Day 3 grading system: This system is used to grade embryos on day 3 after fertilisation. Embryos are typically graded on a scale from 1 to 5, I would suggest referring and checking with your clinic as to which end of the numeric scale refers to the highest and lowest as not all do it in number sequence. The grading is based on the number and quality of cells, as well as the presence of any abnormalities or fragmentation.
- Day 5 grading system: This system is used to grade embryos on day 5 after fertilisation, when they have reached what is known as the blastocyst stage. Embryos are typically graded on a scale from A to C, again check with your clinic that A might refer to the highest quality in this case, generally it does. The grading is based on the size and quality of the inner cell mass (ICM) and the trophectoderm (TE) cells, which are the two main components of the blastocyst.
- Expanded blastocyst grading system: This system is used to grade embryos at the expanded blastocyst stage, which is typically a day or two after the blastocyst stage. Embryos are typically graded on a scale from 1 to 6.The grading is based on the size and quality of the ICM and TE cells, as well as the presence of any abnormalities or fragmentation.
It's important to note that embryo grading is not an exact science and there is some subjectivity involved in the grading process. Different embryologists may have slightly different opinions on the quality of an embryo based on their experience and training.
Now that we can understand the basics of embryo grading, let's dive into what embryos need to do to receive a good grade………..
Embryos are graded based on several criteria, including the number and quality of cells, the shape and size of the embryo, and the presence of any abnormalities or fragmentation as outlined above. To receive a good grade, embryos must meet certain benchmarks in each of these areas.
First, let's talk about the number and quality of cells. Embryos that are growing and developing at a healthy rate will typically have a higher number of cells and a lower level of fragmentation. Fragmentation occurs when cells break off from the embryo, which can indicate that the embryo is not developing properly. Embryos with a high level of fragmentation are typically given a lower grade.
Embryos that are developing well will also have a uniform shape and size. An irregular shape or size can indicate that the embryo is not developing properly or may have genetic abnormalities. Embryos with irregularities may receive a lower grade.
Another important factor in embryo grading is the development stage. Embryos that reach certain development milestones on schedule are typically given higher grades. For example, embryos that reach the blastocyst stage on day 5 are typically considered to be developing well and may receive a higher grade.
The quality of the inner cell mass (ICM) and the trophectoderm (TE) cells are also important factors in embryo grading. The ICM is the cluster of cells that will eventually become the foetus, while the TE cells will develop into the placenta. Embryos with high-quality ICM and TE cells are typically given a higher grade, as this indicates that the embryo has a greater potential for implantation and development.
There are several things that embryos can do to increase their chances of receiving a good grade. First and foremost, embryos need to be healthy and growing at a healthy rate. This means that they need to have the right nutrients and environment to support their development. Fertility clinics will typically provide a nurturing environment for embryos during the IVF process, but we can also take steps to optimise their health and wellbeing to support embryo development.
One of the most important things for us to do to support embryo development is to maintain a healthy lifestyle. This includes eating a nutritious diet, getting regular exercise, and avoiding unhealthy habits like smoking and excessive alcohol consumption. We may also be advised to take certain supplements or medications to support their fertility and embryo development. This is why you see so much hype around this topic (I'll do another blog later around suggested supplements and why), and why here in the UK there is quite a stringent set of criteria to meet before being able to embark on a round of IVF. It is often recommended to follow a Mediterranean diet for the duration of your treatment cycle as well as before and after to give the best possible chance for success.
Another important factor in embryo development is the quality of the sperm and eggs used in the IVF process. Sometimes we may undergo genetic testing or other evaluations to determine the quality of our eggs and sperm. If there are any issues with the quality of the gametes, we may be advised to consider using donor eggs or sperm to increase their chances of success.
Finally, i’d suggest working closely with your chosen fertility clinic and embryologist to optimise your IVF cycle and increase your chances of success. This may include adjusting medication dosages or timing of certain procedures to ensure that the embryos are developing on schedule and at a healthy rate.
In conclusion, embryo grading is an important tool used by fertility clinics and embryologists to evaluate the quality and potential of embryos during the IVF process. Embryos are graded based on several criteria, including the number and quality of cells, the shape and size of the embryo, and the presence of any abnormalities or fragmentation. To receive a good grade, embryos need to be healthy and growing at a healthy rate, and they need to reach certain developmental milestones on schedule. You can take steps to optimise your health and wellbeing to support embryo development, and work closely with your fertility clinic and embryologist to increase your chances of success.