Low embryo count - looking for reasons

[Syaa]

17 eggs retrieved. 13 were mature . 3 made it to the blastocyst stage. 1 fresh embryo transfer and only 1 out of the other 2 percent passed the genetic test. What could be the cause of such low counts ? Btw the fresh embryo transfer resulted in m/c in 5 weeks.

I now it sounds low but betting 3 blastocysts to freeze/transfer (taking PGS our of the equation) is actually "normal" - most people get just one embryo to transfer and a spare (sometimes not even the spare)

How old are you? If you are mid to late 30s and certainly if you are over 40 that all sounds normal?

How many embryos dropped off between day 3 and 5 as sometimes this can indicate a sperm issue if you had good quality embryos on day 3 which didn't make blastocyst?

For me I was getting good egg numbers but rubbish fertilisation rates and average quality blastocysts. No matter what the clinic did I never got more than 2 blastocysts per cycle (I've done 5 rounds of IVF). My clinic said some people's bodies just can't make more than that (remember the body usually only has to make 1!). I changed protocol to natural modified IVF to make those 2 blastocysts the best quality they could be and that worked for me and am now pregnant with twins