Summary
Definition
History and exam
Key diagnostic factors
- presence of risk factors (usually asymptomatic)
Other diagnostic factors
- polyuria
- polydipsia
- fetal macrosomia in a previous pregnancy
Risk factors
- elevated BMI
- previous gestational diabetes
- previous macrosomic baby
- family history of diabetes mellitus
- non-white ancestry
- advanced maternal age (>40 years)
- polycystic ovarian syndrome (PCOS)
Diagnostic investigations
1st investigations to order
- oral glucose tolerance test (OGTT)
Investigations to consider
- random blood (plasma) glucose
- HbA1c
- fasting plasma glucose (FPG)
Treatment algorithm
fasting plasma glucose ≥7 mmol/L (or 6 to 6.9 mmol/L if large fetus/polyhydramnios)
fasting plasma glucose <7 mmol/L without large fetus/polyhydramnios
labour
Contributors
Authors
Eleanor Scott, BM, BS, MD, FRCP
Professor of Medicine (Diabetes and Maternal Health)
Leeds Institute of Cardiovascular and Metabolic Medicine
Leeds Centre for Diabetes and Endocrinology
Leeds
UK
Disclosures
ES has received honoraria from Abbott Diabetes Care and Lilly Diabetes for giving talks, workshops, and advisory panels. ES has received research grant funding from MRC, NIHR, and Diabetes UK.
Rebecca Spencer, MBChB, BSc, MRCOG, PhD
NIHR Clinical Lecturer in Obstetrics and Gynaecology
University of Leeds
Leeds
UK
Disclosures
None disclosed.
Acknowledgements
Dr Scott and Dr Spencer would like to gratefully acknowledge Dr Ellen W. Seely, Dr Chloe Zera, Dr Jeremy Soule and Dr Leonard E. Egede, previous contributors to this topic.
Disclosures
EWS and CZ declare that they have no competing interests. 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
Helen Murphy, MBBch, BAO, FRACP, MD
Clinical Professor in Medicine (Diabetes and Antenatal Care)
University of East Anglia
Norwich
UK
Disclosures
HM sits on the Medtronic (insulin pump and CGM manufacturer) European scientific advisory board. HM has received research support (CGM sensors and insulin pumps) at reduced cost from Medtronic, Dexcom, and Johnson & Johnson. MH has contributed to educational events sponsored by NovoNordisk, Medtronic, Dexcom, and Abbott Diabetes Care.
Differentials
- Type 1 diabetes
- Type 2 diabetes
More DifferentialsGuidelines
- Standards of medical care in diabetes - 2022
- Diabetes in pregnancy: management from preconception to the postnatal period
More GuidelinesPatient leaflets
Diabetes that develops in pregnancy (gestational diabetes)
Diabetes: what can I do to keep healthy?
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