Thoughts and questions on abortion

[Zandor]

My position is abortion should be allowed through five or six months. At that point, the fetus is passing through to viability/personhood.

Does Roe v Wade guarantee the right to choice for six months or up through birth? I have heard both versions.

How can we assure a certain point at which viability or personhood has not been reached? Whatever the criteria, wouldn't it vary and be an inexact calculation? Put another way, how do we assure we don't err on the side of allowing an abortion when the fetus is viable?

These questions have been posed to me in the past and are difficult to answer.

Thank you in advance.