Blastocyst how many

This group of cells is given a letter grade of either A, B, or C. Grades A and B are most desirable and reflect a good number of cells with normal appearances. Therefore only those cells graded A or B are selected to be cryopreserved. The trophectoderm represents the collection of cells that will become the placenta and are responsible for the initial invasion and implantation of the embryo into the uterine lining.

This is also given letter grades of A, B, or C. Just as with the inner cell mass, grades A and B are most desirable. Though embryos are graded to signify their stage of development, it is important to remember that the grade does not always reflect the true potential of an embryo. Specifically, there are embryos that receive less than ideal grades that frequently create beautiful babies.

Embryo grading helps us determine how many embryos to transfer. It is important to remember that embryo grading is subjective and that IVF programs may vary somewhat in assigning grades to embryos.

If you have further questions about IVF, feel free to contact us today. Request a New Patient Appointment. These blastocysts freeze and thaw well, as evidenced by the rate of pregnancy in frozen embryo transfers the same as fresh. There is tremendous attrition from egg numbers to blastocysts for transfer or freezing.

Typically, it goes something like this: 10 eggs, 8 mature eggs, 6 fertilized embryos, 4 eight cell embryos, 2 to 3 blastocysts. If the egg numbers are larger than 20, we typically have more immature eggs in the bunch. Cycles with between 5 and 10 eggs often yield the same numbers of blastocysts as those cycles with 15 to 20 eggs. The ideal cycle is one that, regardless of the egg number, results in a blastocyst for transfer or cryopreservation.

Eggs, embryos and blastocysts. Share This Story! Contact Information. Related articles. Probably a more important reason to perform transfers at the blastocyst stage is that we have a better idea of the quality of the embryo just by the fact that it survived to day 5 or 6. On average, only 30 to 50 percent of embryos make it to the blastocyst stage.

The failure of some embryos to not make it to the blastocyst stage is most likely due to a defect in the embryo. If, for example, we have 10 embryos on day 3 and we select two to transfer on day 3, we may not select the right embryos.

The probability that we select the three or five that would have gone to day 5 or 6 is not very high. In this instance we will be transferring some day 3 embryos that really have no chance of making it to day 5 or 6. If instead we wait a few more days when we know which embryos are competent to make a blastocyst, we will increase our odds of the embryos implanting.

Most studies indicate the chance for a day 3 embryo to implant is about 20 percent. This is like having a six-sided dice and having to roll a one or a two for implantation to occur. It is much better to pick a blastocyst, where implantation rates are in the 50 percent range — like flipping a coin and having to decide between heads or tails. Though some patients going through infertility treatment might want twins or higher multiple pregnancies, these are higher risk than single pregnancies.

Multiple pregnancies can cause serious complications and health risks to both mother and child. These risks can be reduced while maintaining good pregnancy rates if embryos are transferred with a higher potential for implantation blastocysts and if fewer embryos are transferred.

As we continue to improve our pregnancy rates at Arizona Reproductive Medicine Specialists, we remain steadfast in promoting single embryo transfers eSET to reduce multiple pregnancies. The only down side to doing a blastocyst transfer is that there may be some risk that no embryos make it over the hurdle and survive to day 5. But, most likely, if none made it to blastocyst in the incubator, they would not do so inside of the woman, and the end result would be the same.

There is also one other very important reason to let embryos develop to the blastocyst stage: Blastocysts freeze better than day 2 or 3 embryos.