Gestational diabetes mellitus

Last reviewed: 2 Sep 2023
Last updated: 21 Mar 2023

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • abnormal oral glucose tolerance test
More key diagnostic factors

Other diagnostic factors

  • polyuria
  • polydipsia
  • fetal macrosomia
Other diagnostic factors

Risk factors

  • advanced maternal age (>40 years)
  • elevated BMI
  • polycystic ovarian syndrome (PCOS)
  • nonwhite ancestry
  • family history of diabetes mellitus
  • previous gestational diabetes
  • increased amniotic fluid volume
More risk factors

Diagnostic investigations

1st investigations to order

  • one-step test option: 75-g oral glucose tolerance test (OGTT)
  • two-step test option: 1-hour 50-g glucose load test (GLT), followed by 3-hour 100-g OGTT
More 1st investigations to order

Investigations to consider

  • fasting blood (plasma) glucose
  • random blood (plasma) glucose
More investigations to consider

Treatment algorithm

ACUTE

pregnant

labor

Contributors

Authors

Ellen W. Seely, MD

Professor of Medicine

Harvard Medical School

Director of Clinical Research

Endocrinology, Diabetes and Hypertension Division

Brigham & Women's Hospital

Boston

MA

Disclosures

EWS declares that she has no competing interests.

Chloe Zera, MD, MPH

Associate Professor

Harvard Medical School

Director, Network Obstetrics Population Health

Division of Maternal Fetal Medicine

Department of Obstetrics and Gynecology

Beth Israel Deaconess Medical Center

Boston

MA

Disclosures

CZ declares that she has no competing interests.

Acknowledgements

Dr Ellen W. Seely and Dr Chloe Zera would like to gratefully acknowledge Dr Jeremy Soule and Dr Leonard E. Egede, previous contributors to this topic.

Disclosures

JS has undertaken research support and speakers' bureau activity for Novartis, Bristol Myers Squibb, Astra Zeneca, and Sanofi-Aventis. LEE is an author of a number of references cited in this topic.

Peer reviewers

Rajesh K. Garg, MD

Professor of Medicine

Director of Clinical Diabetes

University of Miami

Miami

FL

Disclosures

RKG declares that he has no competing interests.

Wail Malaty, MD

Clinical Professor

Department of Family Medicine

University of North Carolina

Chapel Hill

Assistant Program Director

MAHEC Rural Family Medicine Residency

Hendersonville

NC

Disclosures

WM declares that he has no competing interests.

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