Car Seats
Car seats used to be way easier from a pediatrician’s point of view. If a kiddo was a certain weight or height, boom! We knew to bump them up to the next car seat or keep them in their current iteration (version) of mobile safety containment. But now, car seats are so high tech and adjustable and mutate to grow with the kids that it is tough to have definitive rules for when kids can go to the next car seat.
The best all-around guidance is from Washington’s Child Restraint Law:
Children ages 2-4 years must ride in a car seat with a harness (rear or forward facing)
Children 4 and older must ride in a car or booster seat until they are 4' 9" tall
Children over height 4' 9" must be secured by a properly fitted seat belt (typically starting at 8-12 years old)
The science behind these laws is super solid and was done by the preeminent child trauma center in the country over at Seattle’s Harborview Medical Center. These rules no doubt save kids’ lives; I have seen it in the trauma bay firsthand.
As far as when to change seats, the general idea is that the longer you can keep your kiddo in their current car seat, the better, as car seats get less and less safe, the more they stop looking like baby car seats. They are still safe, don’t get me wrong, but just don’t provide as much all-over protection as the super baby seats.
So what I always recommend is that when you get your car seat for your baby or kiddo, write the top limits for the seat in terms of height and weight on a sticker and stick that sticker on the car seat where it’s easy to see. Then when you leave your kiddo’s well-child visit with a new weight and height, check to see if they have outgrown their seat right then and there.
There are some caveats to that, though. Sometimes I will have this healthy string bean of a kiddo that according to their weight, they can stay in the smaller seat, but due to their height, their knees are pushed up into their faces. I usually say that if the next seat up is rated for their current height and weight, and it is a battle to get little Johnny or Jenny into the seat because they are so uncomfortable, then bumping up to the next seat can happen. A good fit with the buckle in a bigger seat is safer than a kiddo fighting the whole car ride to loosen or get out of the smaller seat. Also if you are able to place the car seat in the center of the back seat, do so. The center is the safest spot for baby for a few reasons. One, it is away from side airbags that can intrude on the car seat and push it out of alignment in an accident. Two, the farther away from the sides, the more “crunch” space is available to allow parts of the car in a collision to bend into the interior of the car without encroaching on the car seat in the middle.
How do you know the straps are tight enough? When you can’t pinch any of the car seat buckle webbing between your fingers that is tight enough. This pinch test should also be done with a kiddo in the car seat buckled up without a big ol’ puffy coat on them. Ditch the jacket when in the car seat as it can overheat the kiddo and make it seem that the buckle straps are tight enough when they can actually be loose enough to allow a kid to “submarine” out of the straps (when a kiddo can wiggle their way out of the correct positioning to be ejected down and out of the car seat in a collision).
Oh, and I know the infant seats come with those little padded things to slide on the straps to go over or near the shoulders. Drop those. They don’t add anything and oftentimes make it hard to tell if the straps are fitting right, and they get super gross when there is spit up and drool all over them.