Updated guidelines on screening for gestational diabetes

Figures & data

Table 1 Advantages and disadvantages of two-step and one-step testing for GDM

Characteristic	Two-step	One-step
Method	In the two-step screening approach, a 50-g GCT followed by a 100-g, 3-hour OGTT. Those who screen positive are followed up by an oral 100-g glucose tolerance test	In the one-step screening approach, 75-or 100-g OGTT is done in all patients, without the preliminary step by GCT
Advantages	• Fewer false positives • Avoids OGTT in more than 75% of the women	• Simple to follow • Easily diagnosed
Disadvantages	• Missed diagnosis: 75% sensitivity with 84% specificity as compared with single-step 100-g OGTT • Delay in initiating treatment even in those who test positive • It requires patients to make two visits for testing, where GCT is not feasible throughout the day	• Poor reproducibility • All women need to come in fasting state

Abbreviations: GDM, gestational diabetes mellitus; GCT, glucose challenge test; OGTT, oral glucose tolerance test.

Table 2 High-risk factors for gestational diabetes mellitus

• Previous history of gestational diabetes mellitus

• Previously elevated blood glucose level

• Maternal age ≥40 years

• Family history of diabetes mellitus (first degree relative with diabetes or a sister with gestational diabetes mellitus)

• Body mass index >35 kg/m^2

• Previous macrosomia (baby with birth weight >4,500 g or >90th centile)

• Polycystic ovary syndrome

• Medications: corticosteroids, antipsychotics

Table 3 Recommendations on various aspects of screening

Recommending body	Criteria	Screening on first antenatal visit	Screening at 24–32 weeks with OGTT	One-step/two-step screening	HbA1c for screening
Endocrine Society, USA^Citation13	IADPSG	Universal	Universal	One-step	No
World Health Organization^Citation14	IADPSG	Universal or Risk factor-based	Universal	One-step	No
ACOG^Citation19	Carpenter and Coustan	Risk factor-based	Universal	Two-step	No
ADA^Citation2	IADPSG/Carpenter and Coustan	Risk factor-based	Universal	Either of one	No
ADIPS^Citation29	IADPSG	Risk factor-based	Universal	One-step	No

Abbreviations: ACOG, American College of Obstetricians and Gynecologists; ADA, American Diabetes Association; ADIPS, Australasian Diabetes in Pregnancy Society; IADPSG, International Association of Diabetes and Pregnancy Study Groups; OGTT, oral glucose tolerance test.

Figure 1 Pragmatic approach to screen women for overt diabetes and GDM.

Abbreviations: FPG, fasting plasma glucose; RBG, random blood glucose; OGTT, oral glucose tolerance test; GDM, gestational diabetes mellitus; GCT, glucose challenge test; h, hour.

Table 4 Pragmatic indications for one- and two-step approaches based on biopsychosocial model

Biological:

One-step preferable: high-risk conditions, with likely chances of having GDM, like obesity, PCOS, etc. Missed or delayed diagnosis in such cases could increase the adverse effects.

Two-step preferable: Medical or obstetrical contraindications for frequent travel. Negative GCT can prevent travel (if GCT could be done on routine antenatal visit) and further testing in nearly 75% of women.

Psychological:

One-step preferable: fear of frequent investigations

Social:

One-step preferable: chances of not following again for OGTT after GCT

Two-step preferable: difficult travel conditions/limited resources to carry out OGTT in every patient (if GCT could be done on routine antenatal visit)

Abbreviations: GCT, glucose challenge test; GDM, gestational diabetes mellitus; OGTT, oral glucose tolerance test; PCOS, polycystic ovarian syndrome.

BlumerIHadarEHaddenDRDiabetes and pregnancy: an endocrine society clinical practice guidelineJ Clin Endocrinol Metab201398114227424924194617

 PubMed Web of Science ®Google Scholar

World Health OrganizationDiagnostic criteria and classification of hyperglycaemia first detected in pregnancyDiabetes Res Clin Pract2014103334136324847517

 PubMed Web of Science ®Google Scholar

Committee on Practice Bulletins – ObstetricsPractice Bulletin No 137: gestational diabetes mellitusObstet Gynecol20131222 Pt 140641623969827

 PubMedGoogle Scholar

American Diabetic AssociationClassification and diagnosis of diabetes mellitusDiabetes Care201538Suppl 1S8S1625537714

 PubMed Web of Science ®Google Scholar

Australasian Diabetes In Pregnancy Society (ADIPS) Consensus Guidelines for the Testing and Diagnosis of Gestational Diabetes Mellitus in Australia Available from: http://www.bhs.org.au/airapps/Services/au/org/bhs/govdoc/files/references/14440.pdfAccessed January 27, 2015

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