I think there is another difference
(though it is not based on any research (of mine) but more on intuition and things I have read): I think that women who give birth in hospitals are far more likely to struggle with mothering (especially first time). I think that the hospital makes the transition far more difficult in that it seperates the woman from her prior self to the mother she becomes. In the hospital, you are a patient, a needy person, someone who needs to be birthed. Once you have your baby in hands you are suddenly a mom who is responsable for another human life. This transition is very sharp in contrast, and I think for many woman, is too intense. At home, giving birth in your own surroundings, going through the whole process with no one but yourself, you BECOME a mom by birthing (I know I'm not explaining my self well). The empowering birth empowers your mothering. This is not to say that every hospital birth disempowerrs women, or that every home birth empowers, but I think generally speaking, a home birth leads women into mothering in a far more natural and smooth way. On the unassisted birth group, there are hardly any stories of PPD (one that I remember), very few seriouse nursing problems (can't recall any formula feeding after te homebirth), and not to mention sibling acceptance. I think that at home, birth can fit into life and pass smoothly with no need for big changes. It blends into the daily life and leaves the mom far closer to where she was before... Sorry for the ramble, I have no time to reread, but hope I'm understood?