I've tried just about every diaper and they all seem to leak. In the day, I put her diaper on loosely and it never leaks. At night when she sleeps, I put it on much tighter and it leaks. It's probably because she's lying on her side but I don't want to control her sleep positions...she is now 9 months old and prefers to sleep on her side. She is a bit on the chubby side...and I have tried upping her diaper size before and it seemed to work until recently. She wears medium in the day and large at nite. Would it be too big for her to wear Xlarge at night? She's only 8.6 kg....Does anyone else have the same problem?