Worry. This is a catch-all word for emotions that can range from mild to heart-pounding, depending on whether your child is merely testing her skills on the playground or pulling out of your hand to run toward traffic.

I’m what an earlier generation liked to call a “worrywart.” I worry about almost everything, but usually succeed in communicating none of that worry to my child. I encourage her to try new things, while taking appropriate care against hazards of course.

Probably most parents are worrywarts to some extent, which is why marketers are so effective at getting us to spend a fortune baby-proofing our homes and buying safety devices.

In my in-box today was a promo for a product called the Snuza. It’s a baby monitor that clips to your infant’s diaper and monitors movement. If the device doesn’t sense a movement in 15 seconds, it stimulates the baby with a “pulsed vibration.” If no movement is sensed after another 5 seconds, an alarm goes off. On the Web site’s frequently-asked-questions page, the maker acknowledges this is not a medical device but is more akin to the heart monitors people wear while they exercise.

As I read all this over, I found myself getting angry at this company for exploiting parents’ fear of sudden infant death syndrome to sell a lifestyle gadget.

You see, my daughter, as readers of this blog know, was a preemie. When she was in the hospital for more than two months, she was hooked up to an actual medical monitor. Learning to interpret the sounds it made took a while. At first, I was worried every time it went off, but the nurses assured me that those weren’t the beeps to be concerned about. Then, one day, I was holding her when it went off with a new sound. Assuming it was one of those unimportant beeps, I ignored it. That was until a nurse quickly came up and started vigorously rubbing my baby’s back to remind her to breath. That wasn’t the only time I had that experience. I, too, learned to rub her back when the monitor went off a certain way.

Then, one day, it was time to take her home, to take her off the monitor where I could watch how fast her heart was beating, how many breaths she took a minute and how much oxygen was in her blood.

It was leap of faith. Faith in the doctors that they wouldn’t send her home before she was ready. Faith that she would be OK. And faith that I would at last get to be her mom in our own home.

I buried my worries and embraced a normal family life. If my daughter had needed a monitor, then the doctors would have sent her home with one. (As, indeed, they did for some preemies.)

What if I had given in to my darker fears and bought a contraption like the Snuza? It’s not a medical device, as the maker clearly states. If your child needed a monitor, wouldn’t you want a medical device that could actually save her life? So who is it for? The parents. To feed their worry. The Web site proclaims: “How did we cope before Snuza? It’s been a great relief to finally get a good night’s sleep.”

What kind of goodnight ritual is it when you attach a monitor to your baby’s diaper? Isn’t that saying, in effect, I don’t trust you to live until morning without this thing? Every new parent has this fear, and every new parent gets over it — except those who are reminded of it daily when they buy products like the Snuza, that is.

I am not minimizing the risk of SIDS. I can easily imagine the agony. But the American SIDS Institute does NOT list devices like the Snuza in its advice for parents, which includes placing infants on their backs to sleep without any soft coverings that can suffocate. New research also shows that having a fan in the room can also lesson the risk of SIDS.

What do you think about devices like the Snuza? More harm than help or a useful addition to the nursery?