Why not announce your gender in a fun, non-harmful way?
Either let your photographer open the secret envelope and you find out the sex of your baby when you receive the images (this would be so fun to do and I'd love to try it with someone!) or use the image as a way to tell friends and family what you're having.
This wasn't the original use for this photo, it was much more a way to mark my own 20 week milestone. But hey ho. Win win.