Oh bless you @Egghatcher you’re so sweet
I’m having a mock cycle with an ERA at the moment, I’ve just had recurrent implantation blood tests. All this stuff is usually considered after about 3-4 unsuccessful cycles but I got a lot of high quality embryos and high rates of euploid embryos so we brought the tests forward as it makes no sense as to why I’ve never been pregnant.
You can always test frozen embryos in the future, you don’t have to decide straight away.
As for the chance of success: my embryos were in an embryoscope (incubator with a microscope) they were monitored and each one was given a score for the chance of success. Although a good score doesn’t mean it’s a euploid embryo, and the only aneuploid embryo I had had a 10/10 score!
Having your embryos PGT-A tested will tell you if they’re euploid (normal), aneuploid (have 1 too many/too little chromosomes- they will either fail to implant, miscarry or result in a condition like Downs Syndrome), mosaic (could work or not work), or inconclusive (no additional information).
So the only real use is to help pick the best one for a transfer. If you ended up with 6 embryos, around 50% will be aneuploid. So the PGT-A may help pick out those ones that won’t work, helping reduce the time to success, but the UK tends to do a trial and error approach and since most aneuploid won’t work anyway, PGT-A is often not recommended.