My son is 9 months and I use this mattress since birth. I had a baby and Always On GERD mattress and made my life easier and my little piece. In fact share the baby's position that minimizes GERD. Super comfortable mattress, the material that surrounds it is pleasant to touch and is not cold and removable for washing. Really limits the movements of our little remaining in place more easily than on flat mattress. Product advise 100% to all mothers. Mattress size: 74 x 46 cm