i'm going to be evil now and tell everyone i didn't retain water OR put on weight while pregnant.
but then being a size 22 when i concieved, the diet change to eat healthy while pregnant was only going to mean i ended up losing some weight.
While i certainly think pregnant women should make an effort to at least look nice, if only because it can make you feel a whole lot more human, i'm not going to say they shouldn't put weight on or retain water, neither are within a persons control, its hormonal and natural for both to happen.