When Angus was born, the paed didn't want him going longer than 3 hours and then 4 due to his low blood sugar but once that fixed up demand feeding was ok. I was expressing after he fed anyway to stimulate supply as I had problems initially. Like Christy, we are now lucky to make it to 4 hours except for the first sleep of the night. I often express before going to bed and freeze to help keep my supply regular and in case that first sleep is a long one (he sometimes skips the 2am feed).