My 7 month old DS has coslept in our bed since about 8 weeks (after initially being in a co sleeping crib next to the bed, which he out grew fairly quickly).
DS wakes fairly regularly and when he does he gets quite wriggly. I've always slept with him at the edge of the bed with a rolled up sheet under the fitted sheet as a 'barrier'. This worked as previously DS didnt move in his sleep and it felt safer as I was worried about DP rolling on him if he went between us.
Now DS is bigger and we've decided to stick with co sleeping until he is a little older and night weaned, I don't feel like my current home made barrier is safe and worry about LO falling off the bed when he wriggles.
I've seen a Lindam guard rail which would attach to our bed which would stop DS from falling but I've read they might be dangerous (although looking at it I can't see how as DS is far too big to get 'stuck' or wedged between the barrier/mattress and I and the material is mesh/breathable).
Has anyone else used these or does any one else have any co-sleeping advice/ tips for wriggly sleeping babies?