Car safety seats are one of the most effective ways to protect children from injury and death in the first years of life. For the best protection in a crash, car seats require infants to be placed in an upright position. However, this posture can partially compress the chest wall and reduce airway size, resulting in lower levels of oxygen.

The study, "A Comparison of Respiratory Patterns in Healthy Term Infants Placed in Car Safety Seats and Beds," compared oxygen levels in 200 newborns while in a hospital crib, car bed and car seat. The mean oxygen saturation level was significantly lower in the car seat (95.7 percent) and the car bed (96.3 percent) compared to the crib (97.9 percent).

Previous studies have found similar effects on premature infants; this study confirms the respiration of full-term infants is also affected by car seats and car beds. The study authors suggest these safety devices should be used only for protection during travel, and not as replacement for cribs.

American Academy of Pediatrics