Day 5 - Assessment of blastocysts

Day 5 - assessment of blastocysts

By day five some of your embryos should have developed into blastocysts, shown on the left.  Blastocysts look very different to embryos, the cells are now starting to specialise into those which will form the baby and those that will form the placenta.

The blastocyst will hatch from the protective ‘shell’ which has surrounded the embryo through its development. This is called the Zona Pellucida. It’s this mass of hatched cells which, once free from its shell, will implant into the lining of your womb and form the pregnancy. You can see a hatching blastocyst below.

The blastocyst is a more advanced development stage, so we know that embryos which form good quality blastocysts have good potential to implant.  Your blastocysts will be graded on the morning of day five using a nationally approved blastocyst grading scheme. We’ll select the one or two strongest looking ones for transfer.

We will call you between the hours of 9:00 and 10:00 again on day five to arrange your embryo transfer the same afternoon. Again, you should make sure you are close to the phone at this time.