I recently discovered that Penny Simkin has a variety of her slide presentations available for free download on her website. What a great resource to have available! One of the presentations is called Normalizing Birth and it has a good section about pain, suffering, and trauma in birth. Also of interest is The Birth Environment: How the place and people impact outcomes. There are also illustrated presentations about the OP fetus, "the seduction of induction," and supporting women who have epidurals.
On the site you will also find several handouts to download as well as extensive information about the impact of childhood sexual abuse on pregnancy, labor, birth, and postpartum.
On Mother's Day Mindful Mama magazine launched a video series and art/photo/essay contest exploring the question "how did becoming a parent transform you?" One of these videos features a short interview with Penny on the topic "birth as a rite of passage."