Figure legend
Figure A Abbreviations: CENTRAL, Cochrane central register of controlled trials; CINAHL, Cumulative index to Nursing and Allied Health Literature; RCT, randomized clinical trial
Figure B
The analyses were conducted using random effects models. Abbreviations: BPD, bronchopulmonary dysplasia; ; IVH, intra ventricular hemorrhage; NEC, necrotizing enterocolitis; NDI, neuro developmental impairment; PMA, postmenstrual age; PVL, periventricular leukomalacia;