Embryo grading is a widely adopted practice in many fertility clinics, but what exactly does it entail, and why is it done?
To begin with, there is no conclusive scientific evidence indicating that embryos with higher grades are more likely to result in a successful pregnancy compared to lower-graded ones.
Why is this the case? Essentially, any egg that fails to fertilise and develop into an embryo is nature’s way of eliminating eggs that are not viable. If an egg is capable of producing a baby, it will fertilise and develop accordingly.
It’s important to note that not all eggs will be suitable for development into embryos, and not all embryos will result in a pregnancy. Even in couples with normal fertility, there is approximately a 25% chance of conception each month. For those seeking assistance through IVF or ICSI, the odds of conception may be lower than 25%, and these procedures aim to improve those personal odds.
You can estimate your chances of pregnancy using this tool: Your IVF Success.
The Grading Process
Once your eggs are collected, prepared, and inseminated via IVF or ICSI, embryologists monitor their development. Typically, they check the embryos on the first, third and fifth days to observe cell division and growth. Depending on the observations, embryos may be frozen for storage or selected for transfer.
Embryologists assess embryos based on their morphology and cell division patterns, using visual criteria and established parameters for normal embryonic development. The universally used embryo grading system is known as the “Gardners scale “ after well known embryologist Dr David Gardner.
Research has shown that while “lower-graded” embryos have a reduced implantation rate compared to “higher-graded” ones, the overall pregnancy rates for implanted embryos are similar, regardless of grade. This means that discarding lower-graded embryos might eliminate potential chances for pregnancy. If an egg successfully develops into an embryo, even if it is of lower grade, it still holds the potential for a successful pregnancy.
The Role of Embryo Grading
Should clinics grade embryos? There’s no right answer, scientifically there is no true benefit, in regards to patient preference and care, that is a personal determination. Identifying and distinguishing the quality of embryos helps in selecting those with a higher chance of implantation. However, if a patient completes an IVF cycle and only has lower-graded embryos, what does this grading mean for them? These embryos represent their only chance, and if they implant, the likelihood of a successful pregnancy is the same.
From a patient’s perspective, the grading of embryos does not necessarily impact the decision to implant them. Patients are unlikely to refuse the implantation of lower-graded embryos or undergo additional egg collections solely to obtain higher-graded ones. For embryologists and doctors, grading might assist in prioritising which embryos to use first, but it generally does not alter the overall treatment plan significantly. Embryos at Demeter Fertility are assessed using the Gardners scale to assist in decisions regarding suitability for transfer or freezing – however they are not assigned a numerical grade which may have been seen at other clinics.
For further reading, you can explore this study on embryo grading.
