To characterize phosphatidylcholine (PC) molecular species in serial gastric aspirates as biomarkers for lung maturity, delivery of aerosolized surfactant (AS), and need for intubation.

In a phase II clinical trial of aerosolized surfactant in preterm neonates with respiratory distress syndrome receiving noninvasive ventilation, infants received a maximum of 2 doses of nebulized beractant. Gastric aspirates were collected before and after each dose and were analyzed for PCs using liquid chromatography mass spectrometry.

Of 149 infants enrolled, gastric aspirates were obtained before (n = 91) and after (n = 94) dose 1, and before (n = 56) and after (n = 57) dose 2 of nebulized beractant. The mean ± SD values of birthweight, gestational age, and age at collection of baseline gastric aspirate were 1.7 ± 0.6 kg, 31.7 ± 2.8 weeks, and 5.5 ± 1.7 hours, respectively. The most abundant PC in beractant and gastric aspirates was PC(16:0/16:0). Advancing gestational age and number of antenatal corticosteroid doses predicted increased gastric aspirate PC(16:0/16:0), whereas maternal diabetes predicted a decrease. Several PCs increased significantly (P < .05) after nebulized beractant, consistent with effective aerosol delivery. Infants who received intubation within 72 hours of birth were more likely to have lower PC(16:0/16:0) levels in baseline gastric aspirates compared with those who did not (P = .024).

PC molecular species in gastric aspirates of preterm neonates are potentially novel and precise biomarkers to assess lung maturity, aerosol delivery, and need for endotracheal intubation.