Embryo development can be an early indicator of which embryos are more likely to become successful pregnancies, but these statistics are not the end of the road.
Read on to learn more about Day 3 embryo cell development and pregnancy success rates, or get in touch with a surrogacy professional to learn how surrogacy may increase your odds of successful pregnancy compared to the statistics listed below.
If you are creating embryos, you can get matched with a surrogate faster when you plan with your surrogacy professional as your embryos are created.
Day 3 Embryo Cell Development [The Cleavage Stage]
This stage of cell division is known as the “cleavage” stage. By day 3, an embryo has typically divided into 8-10 cells. This is typically the earliest time that embryos are graded and is typically the earliest time your fertility specialist may consider an embryo transfer.
Day 3 Embryo Grading
Grading on day 3 of embryo development is based on the number of cells in the embryo (with more cells generally being better) and the appearance of the cells.
Embryo grading helps medical professionals determine which embryos are most likely to develop successfully and choose which embryos will be transferred to the uterus during IVF.
Embryologists are looking for even shape and size—abnormal appearance may mean a lower grading. Since day 3 embryo grading is largely determined by cell number, below we will give an overview of day 3 success rates on day 3 below.
Grading scales generally use a letter or number ranking system. For example, a Grade 1 or Grade A embryo would be deemed most likely to be successful, while Grade 4 or Grade D embryos would be considered least likely to be successful.
Day 3 Embryo Success Rates by Cell Number
Below is some information we have gathered from research and fertility clinics on success rates based on the number of cells—generally the more cells the better. But it’s important to point out that the number of cells is only one of many factors that can affect embryo development.
4-Cell Embryos Day 3 Success Rates
Some research shows that day 3 4-cell embryo success is nearly 50% lower than the success rates for embryos with more than 4 cells on day 3. However, if day 3 embryos reach the blastocyst stage, the success rate is similar to other embryos.
There have been many 4-cell embryo day 3 success stories, and one strategy that fertility specialists may use is to continue to observe 4-cell embryos until they reach the blastocyst stage—this can indicate which embryos may be more successful.
5-Cell Embryos on Day 3 Success Rates
Since cells don’t divide at the same time, some embryos may have 5 cells when observed on day 3. Similar to 4-cell embryos, there are many 5-cell embryo day 3 success stories, but overall 5-cell embryos on day 2 tend to have lower transfer success than embryos with more cells.
6-Cell Embryos on Day 3 Success Rates
Day 3 6-cell embryos have success rates that are generally higher than the 4-cell or 5-cell, but lower than the ideal 8-cell embryos.
6-cell embryos on day 3 are generally graded as “good” if the cells are developing normally, and there are many 6-cell embryo day 3 success stories. One study showed that 6-cell embryos on day 3 had a 41.9% chance of becoming live births in women 35 years old or younger.
8-Cell Embryos on Day 3 Success Rates
For 8-cell embryos, 3 day transfer success is significantly higher than for embryos with fewer cells.
If you’re looking for 8-cell embryo day 3 success stories, the good news is that there are many success stories for 3 day embryos that have 8 cells. 8 cell embryos on day 3 are considered optimal, and these embryos will more likely develop into blastocysts and result in healthy pregnancies.
9-Cell to 12-Cell Embryos on Day 3 Success Rates
9-cell embryo day 3 success rates all the way up to 12-cell day 3 embryo success rates are still high— similar to 8-cell embryos. When the cells in the embryos are healthy, there is an even higher chance of success.
Embryos with a higher number of cells are more likely to be transferred on day 3 and are more likely to turn into blastocysts and get transferred on day 5 as well.