Lori Allen

Dresses with simple skirts and empire waists are the easiest to alter for maternity needs.

Image courtesy DCL

Maternity Alterations

And speaking of labor, maternity alterations are another special-case scenario. The dress has to accommodate a growing bust and belly. "It helps to start by picking the right dress," Krystle says. "It's always best to get a maternity dress for a girl who's pregnant; if she finds out later [that she's pregnant], it's a bit of a guessing game."

A woman doesn't know how her body will change during pregnancy, but a good seamstress can help a bridesmaid fit comfortably into her gown. At Bridals by Lori, the consultants usually advise ordering 2 yards of fabric with the dress. They'll replace the skirt with an empire waist. Of course, this works best for a simple dress without ruching or pleating on the bottom.

On average, Krystle and Courtney estimate that the cost of upgrading a regular bridesmaid dress to a maternity one will run about $80, plus the cost of fabric.