The end point of an IVF treatment cycle is an embryo; and an IVF lab will successfully create many embryos in the lab for most of their patients. Good IVF labs routinely show patients their embryos; but unfortunately many labs don't, which means most patients are clueless about how good the quality of their embryos is. However, this is vitally important information, so you can assess your chances of conceiving, and modify the next treatment cycle accordingly.
Here's a visual guide to embryos, so you can appreciate what your embryos are meant to look like.
This is a 2-cell embryo on Day 2. The zona ( shell) is normal and uniform; each of the cells ( called blastomeres) is equal in size with a clear cytoplasm. You can also see a single central nucleus clearly in the right hand cell. There are a few fragments as well, which appear like bubbles, but since these are less than 10%, this would be considered to a Grade A embryo.
This is a 4-cell embryo on Day 2. The cells are clear and equal; and there is less than 10% fragmentation, which makes this a Grade A embryo. This is better than a 2-cell embryo, because it is dividing more rapidly, and has a better chance of becoming a baby !
This is a Grade A 5-cell embryo on Day 2. The reason I have included this image is to emphasise that not all the cells in an embryo divide at the same time, so it's perfectly normal to see embryos which have an odd number of cells ! You can clearly see the central nucleus in the top cell.
This is a 8-cell embryo on Day 3. The cells are clear and equal; and there is no fragmentation, which makes this a Grade A embryo.This is the sort of embryo which delights an embryologist's heart !
This is a 10-cell compacting embryo on Day 3. The edges between the cells are getting blurred, so it's becoming harder to count the number of cells.
This is a morula on Day 4. The cells borders have become indistinct and are said to be compacting.
This a hatched expanded blastocyst on Day 6. This is a perfect embryo - every embryologist's dream ! You can see that the blastocyst has escaped from the zona ( which means it has hatched); and that the blastocyst is now much larger from the zona ( which means it has expanded). Such an embryo has no business not becoming a baby when transferred into the uterus, but the implantation rate even with such a beautiful embryo is only 40%.
This is a schematic of how we grade Day 3 embryos
This is a schematic of how we grade blastocysts
You can see some more pictures of embryos on the next page.