I am a 32 year old adult with PKU. I too went off diet when I was young, and stayed off until my husband and I started to plan a family. We have 2 beautiful, healthy children 5, and 2 years old. I went back on diet before conceiving my first child, and had very good control with my levels. My second was a lot more difficult because I had horrible morning sickness, so my levels were harder to control. It was extremely difficult for me to drink formula and keep it down. I know how hard it is, especially when you are used to eating anything you want, but it is so well worth it. Both of my babies are completely healthy! Hang in there! You can do it!