Bed-sharing is a subcategory of co-sleeping, wherein the parent or parents sleep in the same bed with their child or infant. It can also be sleeping on the same surface such as chair, sofa or bed. It is often done by mothers or caregivers to extend breastfeeding, to employ easy access to breast for night feeds, and to foster bonding and physical closeness with infants. Bed-sharing has been linked to an increased risk of sudden infant death syndrome (SIDS). However, other studies suggest that bed-sharing may not be as dangerous as what was originally believed.