I think the best thing would be to gradually go back on the diet. I have never been off of it but I know how hard it is to resist certain foods. I would say start with simple things like oranges (and other fruits and veggies high in phe), diet sodas, and cookies. Raplace pastas with the PKU friendly versions and progress to staying away from meat, seafood, and dairy. Those are definitely the most important to stay away from when you are pregnant since they usually contain the most protein.