Car seats can be tricky. What if you have done everything you can to safely secure your child in his or her car seat, but it still doesn’t seem to fit correctly? Parents may be tempted to use something to help their child fit snug in their car seat. This is not always safe, but there are instances where you can use items to prop your child into a more comfortable position in the car. Here we will discuss when it is not safe, when it is allowed, and how to know the difference.

After-market products are items sold separately from your car seat. There are many things available for purchase at your local store, online, and even homemade items that serve as decoration for your car seat. None of these items are recommended! Your car seat was not crash-tested with any of these items, so they cannot guarantee the safety of your child. There are certain car seats that will allow the use of a receiving blanket, small towel, or washcloth to be rolled and positioned along the sides or in a U-shape around the crotch strap if the harness doesn’t seem to fit your child well. Not all car seats allow this, however, so you must always refer to your car seat manual before using anything to prop up your child.

You should also refer to your car seat manual regarding any inserts that come with your car seat. Infant carrier–type car seats, which are only used in the rear-facing position, usually come with inserts that may be used to position the baby. However, many of these inserts come with a weight limit, so be sure to refer to your manual to know when it is time to remove them.

Convertible type car seats that can be used in the rear facing or forward facing positions may have inserts that should be used in one position, but not the other. It is important to note that you should not use any additional inserts. For example, if the harness was too loose for your child you should not use an insert from an old car seat to help prop him or her into position. Again, refer to your manual because every car seat is different.

Car seats are built to be unique and to serve the needs of individual families and to fit into many types of vehicles. Because of this, there is not one size fits all. The only rule that holds true for all types of car seats is to refer to your manual. Keep it in your car always. You can also have your car seat installed by a child passenger safety technician. Go to to find a car seat check event in your community or to schedule an appointment.



  • It can be hard to make your baby snug in a car seat, even if it’s installed correctly.
  • Do not use non-approved items to support your baby, including blankets or pillows.
  • Check your car seat’s manual to see what can be safely used in the car seat.
  • Have your car seat installed by a professional.

Last reviewed by Kristie Rivers, MD, FAAP. Review Date: June 2021


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