This may not be an issue for anyone else, but I thought I would mention it because it really shocked me.
I purchased a bra at Motherhood Maternity in mid April. After wearing it for 3, maybe pushing 4 weeks (no more than 3 days a week, sometimes less), the underwire pushed through the encasing to where it just slides out, making it now completely unwearable. I thought maybe it was a fluke and needed to buy some more bras so I went to Motherhood last weekend. Before I picked anything out I mentioned to one of the sales people what had happened and she told me that I shouldn't expect their bras to last a long time and that the lesser quality was reflected in their price. I said wouldn't you expect it to last more than a month and she said not necessarily.
So while I agree that their bras are fairly inexpensive at $25ish each, I would expect them to last longer than a month, especially wearing them only 2-3 times a week. I have bras that I've had for more than a year that only cost $35 and they are still in good condition, so I know not all less expensive bras are cheaply made.
I'm sure others have had good experiences with the Motherhood bras, but I wanted to mention this to anyone who is purchasing from there, just as a heads up.