co-sleeping 
noun [mass noun]
The practice of parents and young children sleeping in the same bed.Particular dangers included co-sleeping with parents, maternal smoking and infants sleeping in the prone (lying face down) position....
- No matter how one views this issue, co-sleeping is most likely under-reported by parents.
- But, when we came around to the topic of co-sleeping, she lowered her voice and took a quick look around before admitting that sometimes she took her own child into bed with her.
Derivatives
co-sleep
- I have carried both my babies in slings, have partially co-slept for a number of months with one.
- According to an American paediatrician, babies suck their thumbs if they aren't breastfed or do not ‘co-sleep’.
- Now with the new co-sleeping cots they can just reach out and soothe the babies, which means both they and their babies are more settled.