RESUMEN
OBJECTIVES: To design a predictive model for assessing the risk of developing respiratory distress syndrome (RDS) using gestational age (GA) and lamellar body counts (LBC). DESIGN AND METHODS: LBCs and patient outcome data was obtained from five medical centers. A total of 223 patients were included in this study; 19 gave birth to infants that developed RDS, 204 gave birth to infants that were unaffected. The absolute risk and odds ratios of an infant developing RDS as a function of GA and LBC were calculated. Logistic analysis was used to model the odds of RDS as a function of GA and LBC. RESULTS: The odds of RDS decreased for each increasing week of GA and decreased with increase in the LBC. GA-specific LBC cutoffs are provided for sensitivities between 84 and 100%. The bias adjusted area under the ROC curve for the classification of RDS, based on GA and LBC, was 0.906 using the logistic model and 0.746 using a single cutoff of LBC (50,000/µL) to classify immaturity. CONCLUSIONS: GA-specific risk assessment and GA-specific cutoffs provide increased sensitivity and specificity in the evaluation of fetal lung maturity.