Epidemiology and predictors of failure of the infant car seat challenge.

OBJECTIVES: The American Academy of Pediatrics recommends all neonates born at <37 weeks' gestation receive a predischarge Infant Car Seat Challenge (ICSC), a resource-intensive test with little information on failure rates and risk factors. We sought to determine incidence and predictors of failure to allow more selective testing.
METHODS: We conducted a retrospective medical record review of 1173 premature neonates qualifying for the ICSC between 2009 and 2010. We looked at ICSC result and potential risk factors and then performed bivariate and multivariable logistic analyses to evaluate for predictors of failure.
RESULTS: Overall incidence of failure was 4.3%. Infants who failed were less premature and had higher birth weights. Late-preterm infants made up 60% of our study population but accounted for 78% of failures (P = .019). Infants who passed had older chronologic ages at time of testing, were more likely to have been exposed to caffeine, and were more likely to have required some type of respiratory support than those that failed. Final multivariable model demonstrated that increasing birth gestational age (GA) increased the odds of failure when corrected for gender, race, and small for GA status. For every 1-day increase in birth GA the odds ratio of failure was 1.03 (95% confidence interval 1.01-1.05).
CONCLUSIONS: We found that increasing birth GA was a significant predictor of failure, and that late-preterm infants comprised a significant percentage of infants who failed. This suggests that limiting testing to extremely premature infants would miss most cases of ICSC failure.