Some more ideas....

Freeze those little baby jube lollies in ice blocks, each guest has to melt their block without biting it, first to 'Give Birth' wins!

Blow up a heap of balloons and put a boys name and a girls name inside and only one balloon has your chosen names, guests have to sit on the balloons to pop them, the person who finds your chosen names wins.

Guess the amount of smarties in the baby bottle

You can give each guest 5 clothes pegs on arrival and if they are caught for eg. crossing legs/feet or saying the word baby they lose a peg to the first person that notices... at the end of the day the person with the most wins!

HTH