title: Protein Intake and Growth in Preterm Infants: A Systematic Review.
abstract: Objective. This review aimed to investigate the relationship between varying levels of enteral protein intake and growth in preterm infants, regardless of feeding method. Data Sources. Electronic databases were searched for relevant studies, as were review articles, reference lists, and text books. Study Selection. Trials were included if they were randomized or quasirandomized, participants were <37 weeks gestation at birth, and protein intakes were intentionally or statistically different between study groups. Trials reporting weight, length, and head circumference gains in infants fed formula, human milk, or fortified human milk were included. Data Extraction. Studies were categorized by feeding-type and relevant data were extracted into summary tables by one reviewer and cross-checked by a second. Data Synthesis. A meta-analysis could not be conducted due to extensive variability among studies; thus, results were synthesized graphically and narratively. Twenty-four trials met the inclusion criteria and were included in a narrative synthesis and 19 in a graphical synthesis of study results. Conclusions. There was extensive variability in study design, participant characteristics, and study quality. Nonetheless, results are fairly consistent that higher protein intake results in increased growth with graphical representation indicating a potentially linear relationship. Additionally, intakes as high as 4.5 g/kg/day were shown to be safe in infants weighing >1000 g.
authors.affiliation: Flinders University, Adelaide, South Australia, Australia; Women's and Children's Health Research Institute, Women's and Children's Hospital and Flinders Medical Centre, Adelaide, South Australia, Australia.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Tonkin
authors.affiliation: Women's and Children's Health Research Institute, Women's and Children's Hospital and Flinders Medical Centre, Adelaide, South Australia, Australia.; Healthy Mothers, Babies and Children, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia; FOODplus Research Centre and School of Paediatrics and Reproductive Health, The University of Adelaide, South Australia, Australia.
authors.forename: Carmel T
authors.initials: CT
authors.lastname: Collins
authors.affiliation: Flinders University, Adelaide, South Australia, Australia.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Miller
keywords: dietary proteins; growth; human milk; infant; premature