目的 分析支气管肺发育不良（BPD）患儿6年的流行病学特点及不同时期BPD临床特点的变化。方法 回顾性收集2015年1月至2020年12月确诊BPD患儿的出生后及母亲孕期的临床资料,根据胎龄和出生体质量分组,比较各组BPD发生率变化趋势;并根据确诊时间分为2015—2017年与2018—2020年两组,比较两组临床特点。结果 2015—2020年共收治1 237例<32周胎龄的早产儿,其中BPD患儿155例（12.5%）。不同胎龄组间BPD发生率的差异有统计学意义（P<0.001）,≤26周早产儿BPD发生率最高,BPD发生率随着胎龄的增大而降低。2015—2020年各年份之间BPD患儿的胎龄分布差异有统计学意义（P=0.001）。2015和2016年以28~32周胎龄的比例较高,2017—2020年以26~29⁺⁶周胎龄的比例较高。不同出生体质量组间BPD发生率的差异有统计学意义（P<0.001）, ≤750g 早产儿BPD发生率最高,BPD发生率随着出生体质量的增大而降低。2015—2020年各年份之间BPD患儿的出生体质量分布差异有统计学意义（P<0.05）。2015和2016年以1 001~1 500g的比例较高,2017年和2018年以751~1 500g的比例较高,2019和2020年以751~1 250g的比例较高。与2015—2017年相比,2018—2020年BPD患儿的胎龄、出生体质量、NCIS评分较低,生理性体质量下降程度≥10%的比例较低,母孕期吸烟或污染空气暴露、呼吸衰竭、贫血的比例较高,开始肠内营养时间及完全肠内营养时间延长,两组间差异有统计学意义（P<0.05）。结论 BPD患儿的出生胎龄及体质量呈下降趋势。母孕期有吸烟或污染空气暴露、呼吸衰竭、贫血的患儿临床工作中应引起重视。

Objective To analyze the epidemiological characteristics of children with bronchopulmonary dysplasia (BPD) for 6 years and clinical characteristics changes of BPD in different periods. Methods Clinical data of children with confirmed BPD after birth and during the mother's pregnancy from January 2015 to December 2020 were retrospectively collected. The children were grouped according to the gestational age and birth weight, and the trend of BPD incidence in each group was compared. According to the time of diagnosis, the children were divided into group 2015-2017 and group 2018-2020 and the clinical characteristics of the two groups were compared. Results From 2015 to 2020, a total of 1237 premature infants with gestational age <32 weeks were admitted to our hospital, including 155 infants with BPD (12.5%). There was significant difference in the incidence of BPD among different gestational age groups (P<0.001). The incidence of BPD among premature infants ≤26 weeks was the highest, and the incidence of BPD decreased with the increase of gestational age. From 2015 to 2020, the gestational age distribution of children with BPD showed statistically significant differences among different years (P=0.001). In 2015 and 2016, the proportion of patients with gestational age of 28 to 32 weeks was higher. The proportion of patients with gestational age of 26-29⁺⁶ weeks from 2017 to 2020 was higher. The incidence of BPD among different birth weight groups was significantly different (P<0.001). The incidence of BPD among premature infants ≤750g was the highest, and the incidence of BPD decreased with the increase of birth weight. From 2015 to 2020, there were statistically significant differences in the birth weight distribution of BPD children in different years (P<0.05). In 2015 and 2016, the proportion of patients with birth weight of 1001-1500g was higher. In 2017 and 2018, the proportion of patients with birth weight of 751-1500 g was higher. In 2019 and 2020, the proportion of patient with birth weight of 751-1250g was higher. Compared with group 2015-2017, BPD children in group 2018-2020 had lower gestational age, lower birth weight and NCIS score, lower proportion of physical body weight decline ≥10%, higher proportion of maternal smoking or exposure to polluted air, higher proportion of respiratory failure and anemia, longer time to start enteral nutrition and to reach complete enteral nutrition. The difference between the two groups was statistically significant (P<0.05). Conclusions BPD happens in early gestational age and cause low birth weight of children. For children with maternal exposure to smoking or air pollution, respiratory failure and anemia after birth, BPD should be considered in clinical work.