I agree with the others - give them a call and find out what they (the hospital) want. When I rang one here in Melb it was suggested that I book into all venues I was considering and then cancel any I didn't want. It was esp important for us because my hosp of choicebooks out very quickly (I was even told by my Ob's receptionist to all her the second I had told DH I had a +ive on a HPT or I'd risk the Ob being full!). SO, really depends on what things are like in your area. Give the venue a buzz, they're almost always really lovely and helpful...

Good luck and a H&H pregnancy to you!
MG