God I hate this discussion, although it is an important one. Only other thing I can think of is with regards to the non-aggression principle. I think the whole personhood discussion cannot (currently) be answered conclusively one way or the other.
Most people are familiar with the non-aggression principle which is you cannot initiate force against another person. One can argue that an unwanted foetus albeit without intent is still aggressing against the woman who is carrying it. Under the non-aggression principle it is permissible to act self-defensively as any mother is actively at risk of permanent injury and even death, so a pregnancy can only proceed with consent of the mother.
It is regrettable that the foetus/baby has to die, but it is the only recourse and is therefore proportional to protect the mother. The more I think about it the less I think an abortion is an aggression in and of itself and simply self defence. If I defend myself or others from a knife wielding maniac and have to regrettably kill them my objective isn't to actively end a life it's to protect my own (or others), thus nobody would label me a murderer, and rightly so. I think I have never been comfortable with pro-lifers labelling abortion as murder for this reason.
The only rebuttal I can think of to this position is that as parents we are responsible for the actions of our children, and thus are responsible for and carry the responsibility for this "aggression". However this can resolve one of two ways either a) parenthood and its attendant responsibilities can only accrue post birth and/or b) as an unborn child cannot by definition act as a moral agent the aggression cannot be the fault of the parents. In addition the father under this approach is 50% responsible for the aggression against the mother irrespective of intent to harm or not.
The absolutely only circumstance I can see of a pregnant woman being guilty of any moral/ethical violation is if she gets pregnant with the sole intention of aborting, but honestly how likely is that to happen? In all other instances it is a self defensive measure, where death isn't the objective, but a regrettable necessity.
For the pro-life lot the job becomes decreasing abortions by campaigning for effective and comprehensive sex ed, and providing resources to reduce the abortions that come about from fears of being able to financially raise a child. So if you must hang around abortion clinics, bring a cheque and offers of support not moral judgements. I'm in favour of abortions not happening wherever possible, but the choice has to remain with the person pregnant. I hope this helps.