Abstract: 　Objective　To explore the clinical characteristics, treatment and prognosis of bronchopulmonary dysplasia (BPD) in extremely preterm infants. Method　The clinical data of extremely preterm infants with gestational age < 28 weeks hospitalized between August 2014 and August 2017 were retrospectively analyzed. According to oxygen inhalation and BPD clinical grading at 28 days after the birth, extremely preterm infants were divided into non-BPD group, mild, moderate and severe BPD groups, and their clinical characteristics, treatment and prognosis were discussed. Results　A total of 205 extremely preterm infants were enrolled, with an average gestational age of (26.2±1.2) weeks and an average birth weight of (0.87±0.19) kg. Among them, 46 infants were gave up treatment, 15 died, and 144 (70.3%) were discharged eventually. There were statistically significant differences in the rates of patent ductus arteriosus (PDA) and infection among groups with different degrees of BPD (P<0.01). The incidence of PDA was higher in the moderate and severe BPD groups, and the infection rate was higher in the severe BPD group. The oxygen use time, length of stay, hospitalization cost, glucocorticoid treatment rate and incidence of pulmonary sequelae among groups with different degrees of BPD were significantly different (P<0.01). With oxygen use time, length of hospital stay and hospitalization cost increased gradually over the aggravation of BPD. Glucocorticoids were used in all moderate and severe children, and the incidence of pulmonary sequelae was higher. Conclusion　BPD still is an important complication affecting the prognosis of extremely preterm infants. Early prevention and systematic treatment can alleviate severe sequela.

Key words: 　extremely preterm infant;　bronchopulmonary dysplasia;　clinical characteristic;　treatment;　prognosis