How to use them safely

Because newer designs are safer, Davis recommends that parents avoid older-model, secondhand bath seats (such as those with suction cups and larger leg holes). The older models' suction cups could give way, causing the seat to tip your baby face-first into the bathwater. And the larger leg holes can allow babies to "submarine," or slide underwater, where they might become trapped.

Newer models have an arm that fits over the side of the tub, but Davis notes that these don't work well on sunken tubs, and the seat can still tip or even break. Follow the manufacturer's instructions when installing the seat, she advises.

Bath rings are inflatable circles that can help your baby stay upright in bathwater. But these may require much more water in the tub to be effective. Safety groups advise keeping the water shallow to minimize the risk of babies drowning.

Most important, no matter which bath seat you choose, never be more than an arm's length away from your baby. Leaving an older, seemingly capable child with your baby isn't safe either. Davis notes that most baby drownings happen while the baby is either unattended or left in the care of an older child.