Once your twins are over their birth weight (and you are given the clear by their pediatrician) you can let your twins sleep at night without waking them up to eat.During the day you should wake your twins to eat every 2.5-3.5 hours to get onto a good consistent schedule. By waking your twins you are making sure that they are eating enough during the day (so they don't need to make it up at night) and that they are getting a consistent schedule built.