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OK, I’ll address some of your numbers here:

“In IVF, according to the references here, 5 to 17 eggs are fertilized. 3 or more are attempted to adhere. The rest are frozen or thrown away. Those that are frozen have a good chance of deteriorating and are not viable in the end.”

I’ll go with your 5-17 eggs fertilized, and I’ll go with your 3 or more replaced in the uterus.

HOWEVER, you state the “rest” (meaning between 2-14, after subtracting out the 3 replaced)are “frozen or thrown away.” Not true.

This is what actually happens: 5 to 17 eggs are fertilized, and only perhaps 50-75% of those make it to the day 3 embryo stage in the embryologist’s lab. (Perhaps as bad an attrition rate as nature, perhaps not, no one really knows.)

So now, by day 3, we are down to perhaps 2 to 8 embryos. Then those embryos are generally grown to the day 5 blastocyst stage (better pregnancy rates result from blast transfers, which is when a fertilized egg would naturally implant in the uterine lining). Perhaps 50-75% of day 3 embryos make it to the blast stage. (Again, perhaps as bad an attrition rate as nature, perhaps not, no one really knows.)

So now we are down to between 1-4 blastocysts available for transfer. Most likely 2 are transferred. So that leaves perhaps 2 available for freezing, at best, but keep in mind only 25% of all IVF cycles result in any embryos left over for freezing.

Frozen embryos are not “not viable in the end;” most clinics have a thaw rate of 75% or better these days. (The chance of them implanting is slightly less than a fresh embryo, but FETs—frozen embryo transfers—are approaching fresh cycle rates in many clinics these days.)

And of those 2 transferred, the most likely result is no prengancy. An IVF cycle with 2 transferred has about a 40% chance of being successful. If there is a pregnancy, the most likely result is a singleton pregnancy.

There is no intentional destruction of embryos in an IVF cycle. Quite the opposite.