By your logic that if the fetus is inside the womb, then it still has human rights. By that logic, can the mother be tried for murder or manslaughter if she miscarries or the umbilical cord is around the throat?
A mother should not be tried for a crime if she miscarries due to natural causes. Approximately half of all pregnancies end in miscarriage.
If a mother intentionally causes a miscarriage through violent acts against her living son or daughter or against herself with the intent to indirectly end her child’s life, then yes, she should be tried and convicted by a jury of her peers. Killing an innocent human being is always wrong, regardless of any excuse or reason given by their killer.