Pregnant customers should go by their pre-pregnancy size, unless their first trimester was a big one, weight-wise. You may have changed dress sizes before you started to show. Each manufacturer, however, has their own quirks. The best way to get the right fit is to know your current numerical dress size, then just apply it to the size chart we have for each item and voila!
The size chart for each item is shown when you pull down the size menu.
The trickiest thing is how to figure out your bra size. Here's a helpful video from Bravado Designs: