Playards can pose suffocation risks, especially if a mattress not designed for the playard is used inside it. Any large holes poked in the mesh can trap children, and wear that leaves sharp edges can injure children.
Older babies and toddlers able to sit or stand up can get entangled and injured in mobiles and other hanging objects. They can also fall and hurt themselves trying to climb out. Remember that if a baby is sleeping in a playard, it should be otherwise empty of all toys, pillows, blankets, etc. This is particularly important if the baby is younger than about 4 months, or not yet able to roll over by themselves.