My DS is 18 weeks and, after several weeks of good sleep, has begun to wake several times in the night. Having read on here that this is quite common at around 4 months I have decided not to stress too much about it (ha ha) and hope it settles down again when he moves onto solids. But one thing I have noticed is that he now moves around the cot quite a bit at night (he is in a Grobag) and I wonder sometimes whether he bashes his arms against the side of the cot and this wakes him. I have a cot bumper but am not using it because I have read that they are not advised before 12 months. Does anyone have any thoughts on this or any tips for other methods to stop him bashing himself on cot sides?