Summary
Definition
History and exam
Key diagnostic factors
- presence of risk factors
- abnormal oral glucose tolerance test
Other diagnostic factors
- polyuria
- polydipsia
- fetal macrosomia
Risk factors
- advanced maternal age (>40 years)
- elevated BMI
- polycystic ovarian syndrome (PCOS)
- ancestry
- family history of type 2 diabetes mellitus
- previous gestational diabetes
- previous macrosomic baby
Diagnostic tests
1st tests 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
Tests to consider
- fasting blood (plasma) glucose
- random blood (plasma) glucose
Treatment algorithm
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 receives author royalties from UpToDate.
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.
References
Key articles
American Diabetes Association. Introduction and methodology: standards of care in diabetes - 2024. Diabetes Care 2024;47(Suppl. 1):S1-S4.Full text
Plows JF, Stanley JL, Baker PN, et al. The pathophysiology of gestational diabetes mellitus. Int J Mol Sci. 2018 Oct 26;19(11):E3342.Full text Abstract
Blonde L, Umpierrez GE, Reddy SS, et al. American Association of Clinical Endocrinology clinical practice guideline: developing a diabetes mellitus comprehensive care plan-2022 update. Endocr Pract. 2022 Oct;28(10):923-1049.Full text Abstract
Metzger BE, Gabbe SG, Persson B, et al; International Association of Diabetes and Pregnancy Study Groups Consensus Panel. International association of diabetes and pregnancy study groups recommendations on the diagnosis and classification of hyperglycemia in pregnancy. Diabetes Care. 2010 Mar;33(3):676-82.Full text Abstract
American College of Obstetricians and Gynecologists. ACOG practice bulletin no.190: gestational diabetes mellitus. Feb 2018 [internet publication].Full text
Reference articles
A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.
Differentials
- Type 1 diabetes
- Type 2 diabetes
More DifferentialsGuidelines
- Standards of care in diabetes
- Practice bulletin no. 229: antepartum fetal surveillance
More GuidelinesPatient information
Diabetes that develops in pregnancy (gestational diabetes)
Diabetes type 2: what treatments work?
More Patient information
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