“…In the third stage, infants < 32 weeks GA were selected and classified as very preterm (≥ 28 to < 32 weeks) or extremely preterm (≥ 22 to < 28 weeks) (Castro et al, 2016;Chawanpaiboon et al, 2019). Infants were further stratified on the basis of weight/gestational age ratio as appropriate for gestational age (AGA), small for gestational age (SGA), or large for gestational age (LGA) (Chun et al, 2017). To analyze factors associated with the unfavorable outcome of preterm infants in this cohort, variables were evaluated according to the characteristics of each group and the chronology of related events, namely: maternal/gestational factors, childbirth-related factors, and neonatal factors.…”