The reason religion is so powerful

[John 6IX Breezy]

I think you should read about acardiac/trap twin, and take note of the effect on the pump twin. Then come back and talk to us about the trap twins inherent value.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3939538/

Given that you are a retired medical professional I'm surprised you question the value of the acardiac twin. The appropriate response is clearly to look for an early intervention to prevent any developmental anomalies, and blood perfusion problems, from ever occurring in the acardiac twin.

The goal of medicine should be to save both twins, not classify one as worthless from the start, wouldn't you agree?

And insofar as you do classify one as valueless and not the other you are proving Neo's point. Such differentiation wouldn't be possible unless embryos are living human organisms from conception, and could lose their life and development. Unless your response is that both the normal twin and the acardiac twin are equal to each other before they are born, I'm not sure how this helps your case.