Mother's Own Milk Compared With Formula Milk for Feeding Preterm or Low Birth Weight Infants: Systematic Review and Meta-analysis

OBJECTIVES: We assessed the effect of feeding preterm or low birth weight infants with infant formula compared with mother's own milk on mortality, morbidity, growth, neurodevelopment, and disability. METHODS: We searched Medline (Ovid), Embase (Ovid), and Cochrane Central Register of Controlled Studies to October 1, 2021. RESULTS: Forty-two studies enrolling 89638 infants fulfilled the inclusion criteria. We did not find evidence of an effect on mortality (odds ratio [OR] 1.26, 95% confidence interval [CI] 0.91-1.76), infection (OR 1.52, 95% CI 0.98-2.37), cognitive neurodevelopment (standardized mean difference -1.30, 95% CI -3.53 to 0.93), or on growth parameters. Formula milk feeding increased the risk of necrotizing enterocolitis (OR 2.99, 95% CI 1.75-5.11). The Grading of Recommendations Assessment, Development, and Evaluation certainty of evidence was low for mortality and necrotizing enterocolitis, and very low for neurodevelopment and growth outcomes. CONCLUSIONS: In preterm and low birth weight infants, low to very low-certainty evidence indicates that feeding with infant formula compared with mother's own milk has little effect on all-cause mortality, infection, growth, or neurodevelopment, and a higher risk of developing necrotizing enterocolitis.