To summarize the clinical characteristics of different degrees of bronchopulmonary dysplasia (BPD) in very/extremely low birth weight infants (VLBWI/ELBWI).

A total of 202 VLBWI/ELBWI who were hospitalized at the neonatal intensive care unit (NICU) of Guangxi Zhuang Autonomous Region Maternal and Child Health Hospital for <32 weeks from July 2015 to January 2019 were enrolled and divided into non-BPD (45 cases), mild BPD (36 cases), moderate BPD (75 cases), and severe BPD (46 cases) groups. The general clinical data, time of mechanical ventilation, and complications were compared among the four groups.

The perinatal factors influencing the severity degree of BPD included gestational age, body weight, premature rupture of membranes, asphyxia, prenatal use of dexamethasone, length of hospital stay, and oxygen therapy time (P＜0.01). There were statistically significant differences in oxygen inhalation, continuous positive airway pressure (CPAP) usage, mechanical ventilation time, and the rate of repeated use of mechanical ventilation among children with different degrees of BPD (P＜0.01). Severe BPD children had the highest repetition rate of mechanical ventilation and required longer time of oxygen intake, noninvasive CPAP usage, or mechanical ventilation. There was a significant difference in the incidence of complications such as persistent pulmonary hypertension, ureaplasma urealyticum infection, and retinopathy of prematurity (ROP) in children with different degrees of BPD (P＜0.05). The incidences of persistent pulmonary hypertension and ureaplasma urealyticum infection were the highest in children with severe BPD, and the incidence of ROP was highest in children with mild BPD.

Gestational age, birth weight, premature rupture of membranes, asphyxia, prenatal use of dexamethasone, length of hospital stay, and oxygen therapy duration are the influencing factors of BPD. Severe BPD children have more complications, and therefore, preventing premature delivery, shortening oxygen therapy time, and reducing repeated machine use can reduce the degree of BPD, reduce complications, and improve the quality of life of premature infants.