Everyone understands that low birthweight babies often come with challenges. However, most expecting parents don’t consider the possibility that the carseat they bought or chose to put on their baby registry might not fit baby well if she or he arrives early or is smaller than average at birth.

Of course, you often have no idea ahead of time that you’re going to have a preemie or smaller-than-average term baby.  But if you’re expecting multiples, have a history of preterm labor or just a history of delivering small babies then you really want to be prepared with a carseat that is likely to fit the baby/babies well regardless of whether they’re 4 lbs or 9 lbs at discharge.   

There are 3 important factors when choosing a carseat that is likely to fit a smaller baby well.  First is the miniumum weight rating.  Most carseats are rated from 5 lbs up.  But many babies are discharged from the hospital weighing less than 5 lbs and the hospital staff might not let you leave with your under-5 lbs-baby in a carseat that has a 5 lbs mimimum weight rating.  Ideally, you want a carseat with a minimum weight rating of 4 lbs or a seat rated simply from “birth” up to whatever the max weight limit is.  

However, the minimum weight rating is only one factor in what you’re looking for in a carseat.  You’re also going to need lower-than-average bottom harness slots (ideally 6″ or lower), OR a carseat that comes with an insert cushion that goes under baby’s bottom which raises them up so that their shoulder level is even with, or slightly above, the bottom harness slots.  To clarify, in a rear-facing carseat, you want the harness straps to be situated “at” or slightly below the child’s shoulder level.  In order to evaluate this properly, you may want to remove the harness strap  covers if your seat came with them (and don’t use any aftermarket strap covers if your carseat didn’t).  In my blog review photos, I almost always ditch the harness strap covers because, in my opinion, they just tend to get in the way more than anything else. 

Speaking of getting in the way, I want to take this opportunity to educate you on the plethora of aftermarket carseat stuff that lines the shelves of every baby store. With the exception of a blanket to put over baby in cooler weather, you only want to use the things that came in the box with your carseat.  Aftermarket carseat products may look helpful or useful but they can be a real detriment to proper usage so they are not recommended.  Products like the Bundle Me are great for the stroller but should never be used with your carseat.  Ditto for aftermarket harness strap covers and aftermarket infant support cushions.  However, there are some safe, recommended alternatives to such products so if you’re looking for suggestions or advice (on this or any other carseat-related topic), please visit our forums HERE and we’ll be happy to help educate you.

Since you probably don’t have a good lifelike preemie doll at home to test your carseat with – you can rely on us to steer you in the right direction when it comes to carseats and smaller babies. All of the seats on this recommended list have been tested by either Darren, Heather or myself using the preemie doll made by Huggable Images and we’re confident that these seats will provide a snug and proper harness fit for the vast majority of babies who measure at least 4 lbs and 17″ (the size and weight of this particular doll).



Updated List of Recommended Carseats for Preemies & Multiples

Chicco KeyFit 30 - rated from 4-30 lbs, infant body support insert for babies 4-11 lbs, base with lock-off. Original model Chicco KeyFit (rated from 4-22 lbs only). FULL REVIEW OF KEYFIT 30 HERE

Safety 1st onBoard 35onBoard 35 Air & onBoard 35 Air SE (Only the “Air” models have premium base with lock-off and Air-Protect Technology).  All models are rated from 4-35 lbs. FULL REVIEW OF ONBOARD 35 AIR HERE

Safety 1st Comfy Carry Elite Plus – budget-friendly; 4-22 lbs. Stick to the “Elite Plus” model since that’s the only version of the Comfy Carry that has an adjustable base. FULL REVIEW HERE 


Britax Chaperone  - Anti-rebound bar; base with lock-off, rated from 4-30 lbs, low birthweight foam insert for babies 4-11 lbs – FULL CHAPERONE REVIEW HERE


Britax B-Safe –  rated from 4-30 lbs, base with lock-off. FULL B-SAFE REVIEW HERE


Evenflo Embrace 35 Deluxe - Another budget-friendly option; 4-35 lbs. FULL EMBRACE 35 REVIEW HERE


Graco SnugRide 35 – specifically the new model with the updated infant insert; new models are rated from 4-35 lbs, base has lock-off. We do NOT recommend the SR35 models rated from 5-35 lbs for preemies or low birthweight infants. FULL REVIEW OF NEW SNUGRIDE 35 HERE