Researchers found that 4.6% of late preterm infants didn't pass car seat screening tests, indicating a risk for deadly breathing difficulties during car seat rides, with the highest odds of failure among those who were in both the newborn nursery and the NICU. The findings in Pediatrics also showed that many of the 24% who failed at least two tests had low oxygen levels or apnea, while 40% had to be given oxygen prior to hospital discharge.