Pregnancy Is One of the Most Unique Human Relationship on Earth

There is no human relationship more complex, more morally unstable than this. Even within the same pregnancy, a person and the fetus she carries can shift between the roles of lover and beloved or host and parasite. Each body is capable of extinguishing the other, although one cannot survive alone. The closest we can find may be conjoined twins but even there, it's not the same thing.