[Analysis of risk factors for post-prematurity respiratory disease in very preterm infants]

Objective: To investigate the risk factors associated with post-prematurity respiratory disease (PPRD) in very preterm infants. Methods: A prospective cohort study was conducted, enrolling 369 very preterm infants who were admitted to the neonatal intensive care unit of Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, within one week of birth from January 2019 to June 2023. Data on maternal and infant clinical characteristics, neonatal morbidities, and treatments during hospitalization were collected. The very preterm infants were divided into 2 groups based on whether they developed PPRD. Continuous variables were compared using Mann-Whitney U test, while categorical variables were compared using χ² tests or continuity correction χ² test. Multivariate Logistic regression analysis was used to identify the independent risk factors for PPRD in very preterm infants. Results: Among the 369 very preterm infants, 217 cases(58.8%) were male, with a gestational age of 30 (28, 31) weeks at birth and a birth weight of 1 320 (1 085, 1 590) g. Of these, 116 cases (31.4%) developed PPRD, while 253 cases (68.6%) did not. The very preterm infants in the PPRD group had a lower gestational age and lower birth weight (both, P<0.001). The PPRD group also had a higher proportion of males, lower Apgar scores at the 1^st minute after birth and the 5^th minutes after birth, a higher rate of born via cesarean delivery, and a higher incidence of bronchopulmonary dysplasia, more pulmonary surfactant treatment, longer durations of mechanical ventilation, longer total oxygen therapy, and lower Z-score for weight at discharge (all P<0.05). Multivariate Logistic regression analysis showed that gestational age (OR=0.85, 95%CI 0.73-0.99, P=0.037), born via cesarean delivery (OR=2.23, 95%CI 1.21-4.10, P=0.010), a duration of mechanical ventilation ≥7 days (OR=2.51, 95%CI 1.43-4.39, P=0.001), and a Z-score for weight at discharge (OR=0.82, 95%CI 0.67-0.99, P=0.040) were all independent risk factors for PPRD in very preterm infants. Conclusion: Very preterm infants with a small gestational age, born via cesarean section, mechanical ventilation ≥7 days, and a low Z-score for weight at discharge should be closely monitored for PPRD, and provided with standardized respiratory management after discharge.