BPD	Bronchopulmonary dysplasia
BW	Birth weight
CI	Confidence interval
FiO2	Fraction of inspired oxygen
GA	Gestational age
IPTW	Inverse probability of treatment weighting
IVH	Intraventricular hemorrhage
NEC	Necrotizing enterocolitis
NICU	Neonatal intensive care unit
OR	Odds ratio
PDA	Patent ductus arteriosus
PMA	Postmenstrual age
PPROM	Preterm premature rupture of membranes
PROM	Premature rupture of membranes
PS	Propensity score
ROP	Retinopathy of prematurity
SGA	Small for gestational age
SMD	Standardized mean difference
SNAPPE-II	Score for Neonatal Acute Physiology with Perinatal Extension-II