Proceedings of a Workshop

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This activity was supported by contracts between the National Academy of Sciences and the Endocrine Society, the U.S. Centers for Disease Control and Prevention, and the U.S. Department of Agriculture. Funding was also provided by the National Academy of Sciences Food and Nutrition Board Fund. Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project.

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Digital Object Identifier: https://doi.org/10.17226/29228

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Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2026. Prepregnancy BMI and gestational weight gain: New evidence, emerging innovations, and policy implications: Proceedings of a workshop. Washington, DC: National Academies Press. https://doi.org/10.17226/29228

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PLANNING COMMITTEE ON EXPLORING NEW EVIDENCE ON WEIGHT GAIN DURING PREGNANCY AND PERINATAL OUTCOMES¹

KATHLEEN M. RASMUSSEN (Chair), Cornell University

ALINE ANDRES, University of Arkansas for Medical Sciences

ESA M. DAVIS, University of Maryland School of Medicine

EMMA M. EGGLESTON, West Virginia University School of Medicine

RICHARD S. LEGRO, Penn State University College of Medicine

EMILY OKEN, Harvard Medical School

LEANNE REDMAN, Pennington Biomedical Research Center

Staff

ALICE VOROSMARTI, Associate Program Officer

JENNIFER STEPHENSON, Research Associate

MELANIE ARTHUR, Research Assistant

ANNE MARIE HOUPPERT, Senior Librarian

ANN L. YAKTINE, Director, Food and Nutrition Board

Consultant

LISA M. BODNAR, University of Pittsburgh

___________________

¹ The National Academies of Sciences, Engineering, and Medicine’s planning committees are solely responsible for organizing the workshop, identifying topics, and choosing speakers. The responsibility for the published Proceedings of a Workshop rests with the workshop rapporteur and the institution.

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Reviewers

This Proceedings of a Workshop was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published proceedings as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the charge. The review comments and draft manuscript remain confidential to protect the integrity of the process.

We thank the following individuals for their review of this proceedings:

Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the content of the proceedings nor did they see the final draft before its release. The review of this proceedings was overseen by ANNA MARIA SIEGA-RIZ, University of Massachusetts Amherst. She was responsible for making certain that an independent examination of this proceedings was carried out in accordance with standards of the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the rapporteur and the National Academies.

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Acknowledgments

The National Academies of Sciences, Engineering, and Medicine’s Planning Committee on Exploring New Evidence on Weight Gain during Pregnancy and Perinatal Outcomes would like to express its sincere gratitude to all the workshop speakers and panelists, who shared their expertise and their time to ensure a workshop replete with informative presentations and rich discussions. Deep appreciation goes to Lisa Bodnar, who served as a consultant to the committee and was instrumental in developing the scoping review. Additional thanks to Jennifer Stephenson for coordinating and conducting the scoping review with assistance from Melanie Arthur, Sarah Poncet, and Alice Vorosmarti. The committee also thanks Lori Brenig, Samantha Chao, Nicole Daniels, and Ann Yaktine for their work in developing the continuing professional education credit for workshop attendees.

This project was funded with generous support from the U.S. Department of Agriculture, the Endocrine Society, and the U.S. Centers for Disease Control and Prevention. The committee wishes to express a sincere thank you to Johanna Dwyer, John W. Erdman, Jr., and Connie Weaver who provided additional support through their contributions to the Food and Nutrition Board Endowment Fund. The committee is grateful for the support of the workshop sponsors and individual donors, without which we could not have undertaken this project.

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Contents

1 Introduction

Setting the Stage

Reflections on the 2009 Guidelines

Review of New Evidence

Response to the 2009 Guidelines

Brazilian Gestational Weight Gain Guidelines

Weighting the Seriousness of Outcomes

Role of Diet in Weight Gain and Pregnancy-Related Outcomes

2 Challenges Posed by Weight Extremes

Challenges Posed by Underweight

Challenges Posed by Severe Obesity

3 Social and Economic Predictors of Prepregnancy BMI and Gestational Weight Gain

Social, Economic, and Policy Predictors

Contribution of Health Inequities

Maternal and Infant Health in the Marshallese Community

4 Exploring Opportunities for Innovation

Public Health Framework

Community: Food As Medicine

Data Aggregation and Linkages

Systems Science

Clinical Approaches

Closing Remarks

References

Appendixes

A Workshop Agenda

B Planning Committee and Speaker Biographies

C Maternal and Child Health Outcomes Associated with Gestational Weight Gain by Body Mass Index: A Scoping Review

Annex: Included Articles

Boxes, Figures, and Tables

BOXES

1-1 Statement of Task

4-1 Considerations for Future Guidelines

4-2 Research Gaps

C-1 Methods Used in Studies to Account for Gestational Age in Measurements of Gestational Weight Gain

FIGURES

1-1 Trends in prevalence of obesity in U.S. adult women

1-2 Trends in prepregnancy BMI, 2011 to 2015

1-3 Proportion of pregnant women gaining less than, within, or more than IOM recommendations, by BMI

1-4 Caloric intake of women who gained inadequate, recommended, or excess weight during pregnancy

3-1 Pathways and mechanisms for social inequalities and pregnancy outcomes

C-1 PRISMA flow diagram of selection process for scoping review on maternal and child health outcomes associated with gestational weight gain by body mass index

C-2 Proportion of articles for maternal and infant/child outcomes, 2008–2025

C-3 Percentage of articles accounting for gestational age: stratified by outcome, 2008–2025

C-4 Infant morbidity and mortality outcomes by subtype, 2008–2025

C-5 Evidence map, top 20 most frequently reported outcomes stratified by BMI prepregnancy or early pregnancy BMI

TABLES

1-1 2009 IOM Guidelines for Weight Gain During Pregnancy, by Prepregnancy BMI

1-2 Brazilian Gestational Weight Gain Guidelines Compared to IOM 2009 Guidelines

C-1 Eligibility Criteria for Scoping Review on Maternal and Child Health Outcomes Associated with Gestational Weight Gain by Body Mass Index

C-2 Sample MEDLINE Search Strategy for Scoping Review on Maternal and Child Outcomes Associated with Gestational Weight Gain by Body Mass Index

C-3 Frequency of Reported Maternal Outcomes, 2008–2025

C-4 Frequency of Reported Infant and Child Outcomes, 2008–2025

Annex C-1 Included Articles by Maternal and Infant and Child Outcomes

Acronyms and Abbreviations