Thanks Rufo, I've been recommended one at Hospiten in Bavaro but will keep Clinica Canela in mind.
I'd previously heard that everyone at Casa De Campo raves about Clinica Canela but I have to say I found their gynocology services a bit lacking - very old and grubby examination room, the doctora didn't ask anything about my medical history (which was completely relevant to the issue and treatment) and seemed more keen on handing out prescriptions for medicine I didn't need.