The objective of this umbrella review is to determine the characteristics of dietary interventions delivered any time before, during or after pregnancy for women living in developed countries, identified in quantitative systematic reviews as effective for improving mother and infant health outcomes and feasible for translation into practice.Specifically, the review will address the following questions:For the purpose of this overview, dietary interventions encompass the broad scope of dietary manipulations, including the direct provision of food and/or nutrients to participants, nutrition education, nutrition counseling, nutrition care teams, or any combination of these four intervention types.Both a narrative and quantitative summary on the effect of maternal dietary interventions on maternal and infant health outcomes as compared with usual care will be provided. The quantitative summary of the maternal and infant outcomes will be supported by an appraisal of the certainty of evidence of the effects and the strength of the recommendations using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework.