For this game, go to a store that has receipts that contain the purchased item names. Purchase 5 baby items.
Give each guest a note card and pencil. Pass each item around and have the guests write down how much they think the item costs. Whoever has the closest total to the actual total wins.
The winner could be given a gift card to a department store or some other gift. The mom-to-be, of course, should go home with the baby items.