Study	Reason for exclusion
Antunes 2003	Intervention started after 48 hours of life
Wu 2015	Mean birth weight was > 2.5 kg (2.75 ± 0.58 in intervention group and 2.92 ± 0.64 in control group), suggesting that included newborns were not ≤ 32 weeks' gestational age as specified in this review