Complementary feeding and developmental milestones: a systematic review

Background: Systematic reviews were conducted as part of the USDA and the US Department of Health and Human Services Pregnancy and Birth to 24 Months Project to examine the relation between complementary feeding and developmental milestones. Objectives: The aim of this study was to describe systematic reviews examining the relationship between timing of introduction of complementary foods and beverages (CFB), and the types and amounts of CFB consumed, and developmental milestones. Methods: The literature was searched using 4 databases (PubMed, Cochrane, Embase, and CINAHL) to identify articles that met predetermined criteria for inclusion. Data extraction and risk of bias assessment were conducted for each included study. The body of evidence for each systematic review was qualitatively synthesized to develop a conclusion statement, and the strength of evidence was graded. Results: Three included articles (1 randomized controlled trial; 2 observational studies) examined timing of introduction of CFB. Eight included articles (3 randomized controlled trials; 5 observational studies) examined types and amounts of CFB. There was insufficient evidence to draw conclusions about the relation between either timing of CFB introduction or types and amounts of CFB, and developmental milestones. Conclusions: The ability to draw conclusions about the relationship between complementary feeding and developmental milestones was restricted by an inadequate amount of evidence with potential for issues with reverse causality and wide variation in design, type/age of outcome assessment, exposure assessment, and reported results. Additional research to address these gaps and limitations would be useful.