Nakashima T, Inoue H, Sakemi Y, et al. - Researchers conducted the study for examining recent trends in bronchopulmonary dysplasia (BPD) and its risk factors among extremely preterm infants. They reviewed demographic and clinical data for 19,370 infants born at 22-27 weeks of gestation registered in the affiliated hospitals of the Neonatal Research Network of Japan between 2003 and 2016. Two thousand two hundred forty-four (11.6%) of the 19,370 infants died at the postmenstrual age of 36 weeks. The mortality rate declined to 8.0% in 2016 from 19.0% in 2003. Multivariable analysis of the survivors exhibited a positive correlation of BPD with ≥ 4 weeks' supplemental oxygen or invasive ventilation, birth weight < 750 g, small for gestational age, ≥ 4 weeks' noninvasive positive pressure ventilation, chorioamnionitis, < 26 weeks’ gestational age, < 20 cases per year of center patient volume, or treated patent ductus arteriosus. The mortality rate for extremely preterm infants has decreased, but the BPD rate in survivors between 2003 and 2016 has risen. Increasing rates of BPD indicate that variations in the patient population or other management strategies affect the development of BPD, despite the decreasing duration of invasive ventilation over time.