Setting up a nursery can set you back a few dollars, so when a friend offers you a free crib mattress -- or you see one out on the side of the street with a "free" sign on it -- you might be tempted. The trouble with a used mattress is that you don't know how it was cared for or if it meets today's safety standards. If you used the mattress yourself for a previous baby, using it again may be safe, as long as you cared for it properly.
Crib mattresses made today provide a firm sleeping surface. As an adult, the mattress might seem too firm to you. But a baby needs a firm surface not only for support but to reduce the risk of smothering. When a mattress is too soft, loses its shape or develops soft spots, the mattress could conform to a baby's face if he rolls over with his face in the mattress, blocking air flow and smothering him. An older mattress might be too soft to use today, either because it was made that way or because it was stored improperly, with heavier items on top of it, weakening it in spots.
A new crib mattress must measure at least 27 1/4 inches by 51 5/8 inches, according to Consumer Reports. Older crib mattresses made smaller might leave a gap between the crib sides and mattresses that could entrap and possibly smother a baby. If you can fit two fingers between the crib side and mattresses, it doesn't fit tightly enough and could pose a risk to your baby. Between January 1, 1997, and July 15, 2002, nine infants, all under age 1 year, died in crib accidents involving improperly-sized mattresses, the U.S. Consumer Safety Product Commission reported.
Diapers leak and urine and feces can seep into a mattress, leaving not only stains but also the possibility of bacterial contamination, which could make a baby ill or possibly contribute to sudden infant death syndrome, although this has not been conclusively proven. In addition, many parents don't have room to leave an unused crib mattress in the house and store it instead in the garage or basement. Both environments can be damp at times, and mold and mildew can grow on or inside a crib mattress, increasing the risk of allergy or respiratory symptoms for a baby. A crib mattress stored in a dry area is safer to reuse.
Several British researchers have proposed theories linking previously used crib mattresses with an increased risk of sudden infant death syndrome, or SIDS. A Scottish study conducted by researchers from the Royal Hospital for Sick Children and published in the November 2002 "BMJ" found a correlation between SIDS death and sleeping on previously used mattresses, especially those that came from someone else's home. However, researchers cautioned that cause and effect weren't conclusively established with this study and offered no explanation for why the connection might exist.