Background: Bronchopulmonary dysplasia (BPD) in preterm infants is one of the most serious complications in neonatology, as it significantly affects the quality of life of preterm children. We retrospectively analyze the incidence and risk factors of BPD in premature infants under 32 weeks of gestation age.
Methods: Clinical data of premature infants with gestational age ≤32 weeks admitted to the neonatal intensive care unit of the First Affiliated Hospital of Nanjing Medical University from 2015 to 2017 were selected for this retrospective case-control study. The patients were classified into the BPD and control groups based on the clinical diagnosis. We compared the general condition, treatments, complications, and clinical outcome of premature infants in both groups. Student’s t-test, non-parametric test, and binary logistic regression were used to analyze the occurrence of BPD and its potential risk factors.
Results: A total of 213 premature infants aged ≤32 gestational weeks were included in the study; of these, 81 (38%) were diagnosed with BPD. The gestational age (29.14±1.88 weeks vs. 30.82±0.98 weeks, P<0.001) and weight (1240±314.87 g vs. 1584.77±318.18 g, P<0.001) in the BPD group were lower than those in the control group. The liquid quantity, urine volume, and calorie intake of preterm infants in the BPD group within one week after birth were significantly lower than those of infants in the control group. Logistic regression analysis showed that invasive mechanical ventilation (OR=5.065, 95% CI: 1.680–15.266); use of erythrocyte suspension (OR=10.146, 95% CI: 1.860–55.336); and PCO2 in early postnatal arterial blood gas (OR=1.122, 95% CI: 1.024–1.229) were risk factors for BPD. On the other hand, gestational age (OR=0.657, 95% CI: 0.460–0.937); calorie intake (OR=0.917, 95% CI: 0.874–0.963); PO2 (OR=0.925, 95% CI: 0.870–0.985); and pH in early postnatal arterial blood gas (OR<0.001, 95% CI: 0.000–0.156) were protective factors for BPD.
Conclusion: The incidence of BPD in very low and extremely low birth weight infants is high. Maintaining early internal environment stability, increasing early calorie intake, shortening invasive mechanical ventilation time, reducing blood transfusion, and closing patent ductus arteriosus could likely reduce the incidence of BPD.