Breast milk reduces the risk of serious prematurity related morbidities. Quality improvement is an effective means of increasing breast milk feeding.Twenty-seven hospitals in China will participate in the study, which aims to increase breastfeeding rate in the NICU and reduce the clinical complications in very low birth weight infants and extremely low birth weight infants. This study compared the clinical data of very low birth weight infants and extremely low birth weight infants in three phases：Before-intervention phase，Intervention phase and Sustainability phase. During the Intervention phase and Sustainability phase multiple intervention bundles of quality improvement were implemented.The investigators will compare breast milk feeding rate and neonatal outcomes in different phases.
Twenty-seven hospitals in China will participate in the study, which aims to increase breastfeeding rate in the neonatal intensive care unit (NICU) and reduce the clinical complications in very low birth weight infants and extremely low birth weight infants.