Now that I am at my desktop computer, I wanted to add a little more info. Once fabric is quilted to batting, it is the batting that controls whether the fabric can shrink or not. With moderate to heavy quilting, basically the fabric cannot shrink more than the batting allows it to. If the batting is polyester and the quilting stitches are an inch or two apart, for example, even flannel (which is notorious for shrinking a *lot* when washed and dried as fabric) will not shrink. If your quilting lines are 12" apart, then there is room for fabric to shrink between quilting lines. However, with moderate quilting fabric will not shrink more than the batting allows.
Batting manufacturers usually post shrinkage information online, and often also on the packages (if you buy batting pre-packaged).