Day 3 vs Day 5 Embryo Transfer

One of the most exciting moments of any surrogacy journey is the embryo transfer.  It is so amazing to be able to see your little embryos when they are only a few days old.  All clinics grade the embryos on a scale (this scale varies from clinic to clinic and often is a combination of letters and numbers).  Most clinics will share your embryos grades with you and explain why they are graded that way.  This analysis helps the RE chose the best embryo(s) to transfer.

Clinics choose to transfer on Day 3 vs Day 5 (some clinics Day 6) for many different reasons.  It is considered the most ideal to transfer on Day 5.  The philosophy is that the longer the embryos are grown in culture, the better the odds of choosing the strongest one(s) to transfer.  Some of the factors in the decision of transfer timing is the number of embryos, the quality of those embryos and the availability of all the parties involved.  I thought it would interesting to share a few pictures of some of Pink & Blue's embryos (those of our IPs).

The above photo is of two Day 3 Morulas.  They are graded fair, you can see the cells are even and there is no major sign of fragmentation.

The above photo is also two Day 3 Morulas.  One is graded very good and the other is fair.  You can see there are more cells in the lower embryo and it looks more even.

The above is a Day 6 Blastocyst.  It was graded excellent.  You can see it is just starting to hatch prior to transfer (unassisted hatching).  The embryo is expanded and even with a clear inner cell mass and a good trophectoderm.

The above are two Day 6 blastocysts.  One is graded excellent and starting to hatch (the right).  The second is starting to collapse prior to transfer.

The above is a Day 5 Blastocyst graded excellent.  You can see the same traits as above.  Expanded, clear inner cell mass and trophectoderm and no fragmentation.

The above is a Day 5 Morula.  It was graded fair.  There is some fragmentation, and it is obviously delayed in development.

The above is a Day 5 Blastocyst that was graded very good.  The inner cell mass was good, there was some irregularity in the trophectoderm.  

It is important not to put too much stock in the grading of your embryos.  I have seen picture perfect, amazing embryos that did not result in a pregnancy.  I have also seen less then ideal, poor grade embryos make the most beautiful babies.  Embryo grading is a tool used to help boost the odds, but it is limited and by no means a guarantee.