Inclusion Criteria:  All infants born at ≤31+6 weeks' gestation and admitted to the participating NICUs between October 1st, 2019 and September 30th, 2023. The period from October 1st, 2019 to September 30th, 2021 will be used as the baseline period before ASP intervention. Clinical data of eligible infants in this period will be retrospectively collected from a previously established database of preterm infants. The ASP implementation will be initiated on October 1st, 2021. The period from October 1st, 2021 to September 31st, 2023 will be the ASP intervention period and data will be prospectively collected.  Exclusion Criteria:  Infants who are transferred to non-participating NICUs within 24 hours after birth.