making unique invitations can be expensive, unless you're happy enough to print the text out on extra thick paper then do something to it afterwards...such as....
-buy a rubber stamp (like a baby pram, or foot prints, or rattles - see hobbycraft online) and blue ink pad. a pattern dotted around will look sweet and simple.
- buy crazy scissors and cut a patterned edge to the invitation
- put a single (or double) hole punch at the top and thread a blue ribbon into a bow
- photocopy an ultrasound scan as the centre of the invitation and add a caption in blue like "mummy's having a party for me...you're invited!"
EDIT: ooh!! also found this - it has a printable invitation templates! they're so sweet! maybe you could do the blue ribbon thingy to these?
http://www.best-baby-shower-planning-gui…