Different Causes of Respiratory Distress in Neonates at Different Gestational Ages in China: A Retrospective Multi-Center Cohort Study

Abstract

Background: Pulmonary surfactant replacement therapy (SRT) is currently the main treatment for neonatal respiratory distress syndrome (NRDS), but not all infants, particularly late-preterm and full-term (LP/FT) infants, with NRDS can achieve a satisfactory outcome despite intensive care and SRT in China. Few studies have been done to investigate the risk factors associated with respiratory distress at different gestational ages to guide clinical treatment. Methods: Therapeutic effects of SRT(conventional dose) in infants at different gestational ages (GAs) were compared in a large retrospective multicenter cohort study performed in 26 neonatal intensive care units in China. The cause of respiratory distress was further analyzed by comparing the different risk factors closely related to NRDS severity at different GAs. Results: The study of 1240 infants with NRDS showed that SRT in a conventional dose was less effective in LP/FT infants than in early-preterm infants. Further analysis of the risk factors of respiratory distress revealed that a GA less than 30 weeks and a lack of prenatal corticosteroid use were closely related to NRDS severity in early-preterm infants, whereas perinatal infection- and perinatal hypoxia-associated risk factors were closely related to NRDS severity in LP/FT infants. Conclusion: The cause of respiratory distress in LP/FT infants might differ from that in early-preterm infants in China. Respiratory distress in early-preterm infants is mostly due to primary surfactant deficiency. However, respiratory distress in LP/FT infants is more likely related to perinatal infection and perinatal hypoxia. Funding: This trial was designed, organized, and implemented by the first author and the corresponding author’s research center. Public funding was obtained from the Emergency Project of the National Science Foundation of China (No. 81741065) and Scientific Research Projects Unit of Chongqing (Project-cstc2016shms-ztzx13001) (Project-cstc2015shmszx1201114). Declaration of Interest: None of the authors have conflicts of interest to disclose. Ethical Approval: The ethics committee of Daping Hospital approved the study protocols, according to the Chinese regulations for clinical investigation.