OP, I was also in your same boat. I decided to be upfront with all of my HCP's about my HB plans, mostly for the same reason as the PP who said that she wanted to normalize it. I wanted the HCP's to be able to treat it as a legitimate option, so I just stood my ground when they fought with me -- then informed them that I would be transferring care to someone who would respect my choices about birthing. I transferred care a LOT during pregnancy. I actually saw something like eight different practitioners while I was pregnant (though, to be fair, there were other reasons for that besides the HB issue).
What I did was, I called the HMO directly, and just kept asking a lot of questions that bewildered them and made them transfer my call all around the whole institution. Questions like, "how do I get my homebirth covered?" and "which of your covered hospitals will provide facilities for my waterbirth?" and "can you provide a list of the midwives in your practice?" I knew perfectly well that they did not cover homebirth, none of their hospitals did waterbirth, and most of them acted like they'd never heard of a midwife. But asking the questions in that way made it clear that the lack of appropriate maternity services for natural childbirth was their problem, not mine, and they started working on bending over backwards to get me the answers -- and care -- that I wanted. This took a lot of time and headaches, but by talking to a lot of nurses, etc., I finally tracked down a sympathetic OB within the HMO.
This OB wasn't "allowed" to officially support my HB, of course, but I informed him from the beginning that I was planning a HB, had already hired a MW, and would be hiring him for shadow care, so he had all that information. Because he was within the HMO, he couldn't "drop" me, even if he wanted to. I think that's likely going to be true for you, too. I decided to keep all my double appts. because DH wanted me to, which was exhausting, and in hindsight, totally unnecessary. The OB did not ask me to schedule as many appts., however, because he knew I was seeing the MW, too. So that was good. You can probably convince your OB to do the same -- especially if, as you say, your OB has a reputation for supporting women's birth options.
Okay, this post is getting way too long, but here's the meat of it -- I was VERY VERY glad I kept my OB for shadow care, and that I was honest with him about my HB plans. Here's why:
He came in AT SIX IN THE MORNING, ON HIS DAY OFF to attend my birth, and the hospital respected my choices and followed my birth plan even though they are NOT a natural birth - friendly hospital AT ALL.
- the HMO paid for some of the prenatal testing I wanted but HB MW wouldn't/couldn't do (GD testing, GBS testing, ultrasound, etc.)
- I was able to run my birth plan by him and have him sign off on it and place it in my file with the HMO and hospital
- I was able to develop a trusting relationship with this OB and was honest with him about my terror of going to the hospital. He actually gave me his personal pager number, and asked my HB MW to call him directly if I was transferring (HMO docs NEVER EVER do this, it was amazing)
- I ended up with a non-emergent transfer after an extremely long labor at home, and because the OB had a) signed off on my birth plan and put it on file as "doctor's orders," b) given me his number, and c) known that I was terrified of a transfer, I was able to have a really good experience at the hospital.
Had I not been honest with my OB, and not established full prenatal care with him, I would not have had the (fairly) positive experience at the hospital that I did. I was VERY grateful that I had done all the extra work to get there, because had I ended up at that hospital and gottend stuck with the doc on-call, I am certain he would have sectioned me just to punish me for attempting a HB. He was a horror movie in person, seriously. My OB stepped in and protected me from a LOT of garbage at the hospital, and served as my advocate when I needed him the most. And he really went way above and beyond the requirements of his job to do it.
Yeah, paying for and going to all the extra appts. sucked, and it took a lot of work to be able to get everything in place that I wanted, but in the end, it was worth every minute and penny to have that birth experience go well even with a transfer as part of the picture.