If by "legitimate" you mean information that you agree with and that ACOG endorses, you will probably be disappointed.
My own very limited background in liberal arts, in addition to just being a living human, show me that life isn't full of guarantees and 'Insert Tab A into Slot Bs'
For me, what the dominant culture calls prenatal 'care', is what I call 'scare', and it would not benefit me and my family to seek it. Do you have ultrasounds performed on your spleen? On your intestines? How often? After all, the fact that you are functioning, digesting, surely isn't adequate insurance that there isn't something wrong, is it? (Read heavy sarcasm on last sentence).
Why treat your uterus differently? In my mind, it's misogyny that has got us treating our womanly parts as ticking time bombs, and personally, I just don't sign up for misogyny. There's enough of it out there without me seeking it and paying for it, yipes!