My 18 week old DS sleeps ok through the night, but during the day will only sleep for anything between 20 minutes and 45 before waking and then is impossible to resettle. When he does get up after these short naps, he is tired, and I have to get through an hour or so of tetching before another nap before he feeds. I've tried 'wake to sleep', his room is pitch black, there's no noise to disturb him, but if anything it's getting worse not better! Does anyone have experience of a baby growing into a longer sleep pattern naturally?