I've been there! I was there for two months as a student volunteer (teaching EFL) back in fall of 2001. It's a really cool city; there are a lot of foreign consulates so you have a large, diverse expat community, plus it's a culturally rich area. It's been a while and I didn't have any experience with birth while I was there, but I'd be happy to help any way I can.
I currently live in Khon Kaen, which is 6 hours northeast of Bangkok, and I do have experience with birth in Thailand now.
(Also, Koh Samui is a little south of Bangkok, maybe about three hours? I haven't been there myself but it's very popular as a getaway from Bangkok).