Last reviewed: June 2020
Last updated: November  2019

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • elevated BMI
  • fetal macrosomia

Risk factors

  • advanced maternal age (>40 years)
  • elevated BMI
  • polycystic ovarian syndrome (PCOS)
  • non-white ancestry
  • family history of diabetes mellitus
  • low-fibre and high-glycaemic index diet
  • weight gain as young adult
  • physical inactivity
  • previous gestational diabetes

Diagnostic investigations

1st investigations to order

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

Investigations to consider

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

Treatment algorithm

Contributors

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.

Assistant 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.

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.

Peer reviewersVIEW ALL

Instructor in Medicine

Brigham and Women's Hospital

Division of Endocrinology

Diabetes and Hypertension

Boston

MA

Disclosures

RKG declares that he has no competing interests.

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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