I have 6 week twins who were born 3 weeks early and have been pretty much on a 3-hour routine since bringing them home from the hospital. I am bf but also supplementing with formula and for the most part, both DS and DD are doing well with the routine, although DS does often have trouble falling asleep for his naps, especially his mid-morning naps. I think it's because of OS so have kept any stimulation to a minimum (sometimes sit in bouncy seat with only music on, no vibration). They both weigh just over 8 lbs.
I have tried to tank up and do the dream feed, but they both wake up in the middle of the night (DD 3 hours after DF and DS 4.5 hrs after). Are they still too young/small to expect them to sleep from 11pm for at least 5 hours to their next feed? How early can you introduce the tank up/DF to the routine? My DH is sleeping in the guest room so I have been doing the night feeds on my own and the sleep deprivation is catching up.