(A little late but...) I said that because, for example I stubbled across a UK show called 'Midwives' and it was about a maternity ward. Most of the people there are what I would call 'nurses' in the US, even if they are Nurse-Midwives by certification. I was expecting the show to be about something more akin to home-births.

I have an aunt that's a neo-natal nurse, and I've never heard her refer to fellow nurses as midwives (but I've never directly asked her before).