Instead of succumbing to the urge to portray cultural differences as a dichotomy between clashing opposites, we should endeavor to note our common humanity, acknowledge the plurality of viewpoints within a given culture, and appreciate that cultures can evolve without being untrue to themselves.
To participate in a lethal injection is to occupy the medical role and use medical training for a purpose that is not part of the goals of medicine and that harms the recipient of treatment.
When a pregnant woman is knowingly causing harm to her unborn child, there are various legal interventions that can be taken to protect the rights if the fetus.