All of them?<quoted text>
Naturally, you feign blissful ignorance regarding all of the "pre-viable" babies saved by NICU interventions.
All two of them?
Unless you've been hearing of >22 week survivals popping up all over the place?
I'm still not sure you're comprehending what viability means.
Premature =/= unviable.
Capable of working successfully; feasible
In this example, the idea of medical viability means capable of surviving.