# IVF - Blastocyst



## Azailier (Apr 16, 2004)

I am on my 4th cycle of IVF and this time the clinic want to put 5 day old embryo's back instead of 3 day old as before.  What are the advantages of this and why hasnt this been done before.   I know this is probably daft but I am worried that waiting till they are 5 days old will harm them or give us even less chance of success.  We did get 5 embryo's this time, not our usual 2 or 3, could this be why they are trying blastocysts.

Any advice would be gratefully recieved.

Thanks


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## Ruth (Aug 6, 2004)

Yes, as the more embryos you have the greater chance of one or two reaching the blastocyst stage. The down side of blastocyst is that occasionally no embryo will reach the right stage and no ET happens. It may of course expain why previous cycles didn't work.

Sarah


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