My DS is 6 mo, and in the last month or so, he seems to be much wetter at night. Lately I have to wake him up, sometimes 2/3 times to change him and his cot as hes soaking and this distressing him, he screams when I disturb him. Ive tried most every nappy on the market. It seems to be leaking out of the top at the back...anybody any suggestions?