As your IVF process begins, you may be eager to find out your likelihood of success.
How many day 3 embryos make it to the blastocyst stage can affect the likelihood of your surrogate becoming pregnant on your IVF and surrogacy journey.
The blastocyst stage is the optimal stage to transfer an embryo, marking an important milestone in the journey towards a successful pregnancy.
By gaining insights into this critical stage of embryo development, you can have an idea of what to expect throughout your IVF journey.
Our professionals can support you while you create embryos, and help you prepare for the next steps of your surrogacy journey so you can avoid delays and have the family you are dreaming of faster.
What is a Blastocyst?
A blastocyst is an early stage of embryo development that typically occurs around day 5.
When an embryo is at the blastocyst stage of development, it looks like a group of cells with two parts:
- The inner cell mass (ICM),which will become the fetus
- The trophectoderm (TE), which will become the placenta
The blastocyst stage is usually reached on day 5 of development, and not all fertilized eggs will become blastocysts.
How is a Blastocyst Formed in IVF?
In IVF, an egg is fertilized outside of the body by medical professionals. After the egg is fertilized in IVF, it divides into two and then 4, then 8, then forms a clump of cells called a morula. After the morula stage, the cells begin forming separate parts of the embryo and supporting tissues in the blastocyst stage.
Why does it matter how many embryos make it to the blastocyst stage?
Determining the percentage of embryos that make it to blastocyst can determine how many chances you have at achieving pregnancy. The more blastocysts you have, the more opportunities you may have to attempt IVF.
What about how many day 3 embryos make it to the blastocyst stage?
Rather than risk the embryos they have “dying” before day 5. For the few or lower quality embryos, they may have a better chance of developing into a blastocyst in the uterus.
In other words, this can help you and your medical professional determine whether a day 3 or day 5 transfer will be a better choice.
How Many of My Embryos Will Make it to Blastocyst?
Assuming that you have several eggs have been fertilized successfully, you can expect that some will be lost throughout the stages of development, but each person’s experience will be unique.
As an example we will say that you start with 10 fertilized eggs at the beginning, and you can see how many embryos continue to develop using statistics from others’ experiences.
On day 1, most (if not all) of the eggs that were fertilized will divide into a 2-cell embryo. For the example with 10 fertilized eggs, we will say that all 10 of the fertilized eggs divide. On day 2, the cells will divide again, and instead of 2 cells, the embryo will be 4 cells. For the example of 10 fertilized eggs, we will say that one embryo stops dividing, and we now have 9 embryos that each contain 4 cells. Most embryos tend to make it to day 3, so this is still early to predict how many will reach the blastocyst stage. For the 10 fertilized egg example, we will estimate that the count will remain at 9 fertilized embryos. The percentage of day 3 embryos that make it to blastocyst stage is approximately 30-50%, which is significantly lower than the number of cells that develop to day 3 embryos. That means that there are usually significant embryo losses between day 3 to day 5. In our example of 10 fertilized eggs, we could estimate that 3 out of our original 10 might be left at the end of day 4—or about 30% of 9 that were developing on day 3.
What Affects How Many Embryos Make it to Blastocyst?
There are many factors that can affect whether an embryo will make it to the blastocyst stage. Some of the contributing factors can include:
Chromosomal abnormalities that cause the cell to stop dividing. Reduced metabolic activity that ultimately leads to the embryo degenerating. Quality of egg and sperm.
Learn more about embryo development and success rates here. If you have few or no blastocysts, learn about how surrogacy can help.
Our surrogacy specialists can help you find a surrogate if you have embryos, and can support you while you find or create embryos.
FAQ
What percentage of embryos make it to blastocyst stage?
Roughly 30-50% of embryos make it to the blastocyst stage, so if you begin with 6 fertilized eggs, you might end up with 2-3 embryos on day 5 when the blastocyst stage begins.
Can all fertilized eggs make it to day 5?
It is possible in some cases that all fertilized eggs make it to day 5, but just because it’s possible doesn’t mean it is likely. Usually 30-50% of embryos make it to day 5 when the blastocyst stage usually begins.
What is a good number of embryos for IVF?
In general, the advice is that the more embryos you have, the better, but every situation is different. A rule of thumb for doctors is 10-12 mature eggs per child will ultimately result in a healthy pregnancy, and 3 fertilized eggs have been shown to have a 95% chance of pregnancy.
Are 3 fertilized eggs good for IVF?
If you have 3 fertilized eggs, you can have up to a 95% chance of having a pregnancy.