Does anyone have any suggestions for improving my 5 month old's daytime naps? He has always been a good sleeper, 12 hours at night from about 3 months and used to be great in the daytime too, nice long naps of 1.5 to 2 hours. However for the last 2 weeks he has suddenly decided to only sleep for 45 minutes at at a time and I'm not sure how to persuade him to lengthen them! Does this sound like the 4 month regression and therefore do I wait it out? He always puts himself to sleep on his own with no sleep aids and I have tried a few things so far without success (a bit of cry it out, going back in to try and resettle him, shortening/extending wake times etc.). Thanks!