I work with the L&D staff at my hospital. They treat the mom's with kindness and respect at all times. They sometimes struggle to remind the moms that a healthy baby is more important than their birth plan. In fact, the team is well aware of the irony that it seems like the best way to have things not go the way the mom wants them to go is to actually do a written birth plan. Sure, we want your birth experience to be just like you've imagined it. But the truth is, it rarely will go like you dreamed. I think the medical team can certainly remind patients to keep their options open. But in the social setting, I think the best response is "That's admirable. I hope it goes well for you." said with the utmost sincerity.