My little guy (well, bug guy00 he is 21 lbs!) is currently in a 1-armed swaddle mode (although he can easily pull his arm out because its just a large kiddopotamus organic thingie) and sleeps on his belly and he is almost 10 months old!
He has been sleeping GREAT this way for the 5 weeks for nights (7pm to 7am and only getting up once a night to nurse! holy crap! please don't let me jinx this!) and also needs this arrangement for naps. If we leave both arms out he feels the need to stand up in his crib and refuse to sleep (unless we let him CIO- I am sure he would go down on his own but we are not interested in doing that).
This being said, we had a hell time between 7 to 8 months when he wouldn't sleep at all unswaddled, but was miserable swaddled because he couldn't soothe himself when he woke up.....so finally we all learned...and he figured out that sleeping on his belly with a crib full of pacis (and one arm still swaddled felt good to him)......but it was a tough few weeks during the learning process!
As a side note, we also found that his sleep improved greatly when we moved his bedtime to 7 instead of 730 or 8. I was surprised--even though I have always heard "sleep begets sleep"--I didn't think that would help him sleep better.
I have finally figured out that I really CAN'T figure out the sleep thing though long term....so I know this great sleeping pattern will soon change, and I will hopefully just roll with the changes as best I can!
