Due to advances in medicine, it is possible to save a fraction of fetuses born prematurely after as little as 22 weeks.

A 22-week fetus, whether inside of a womb or outside, is not a human being. It is only a potential future human being.

If you give birth to one, you can try to keep it alive until it becomes a human being. But unless we were in a space colony with an urgent need to increase the population, I will not drop anything to help you, and I don't think it's a good use of our tax money. There is a superfluity of babies that are born without such extraordinary efforts — and there are millions of real, existing, human beings that already exist and need help. I think real existing human beings should have priority over potential future human beings.

Writers have envisioned artificial wombs in which a zygote can develop into a fetus and eventually into a human being. Perhaps some day we will build them. That won't create an obligation to use them for every zygote.