Volume 176 - Issue 7
Guidelines for the management of gestational diabetes mellitus revisited
Authors: David S Simmons, Barry N J Walters, Peter Wein and N Wah Cheung, on behalf of the Australasian Diabetes in Pregnancy Society
Med J Aust 2002; 176 (7): 352. || doi: 10.5694/j.1326-5377.2002.tb04441.x
Published online: 1 April 2002
Published online: 1 April 2002
To the Editor: In 1998, the Australasian Diabetes in Pregnancy Society (ADIPS) published management guidelines for gestational diabetes mellitus (GDM).1 Recently, the American College of Obstetricians and Gynecologists (ACOG) published its clinical management guidelines for GDM.2 The Table shows there are few differences from the ADIPS guidelines. At this stage, ADIPS does not consider existing evidence warrants revision of its guidelines. ADIPS will retain its existing criteria for the diagnosis of GDM based on a 75 g oral glucose tolerance test (OGTT) pending publication of the Hyperglycaemia and Adverse Pregnancy Outcome Study.3 The results of this international prospective study of 25 000 pregnant women should be available in June 2004.
A second publication, the draft National evidence-based guidelines for the management of Type 2 diabetes mellitus,4 does not include GDM, but initially recommended that "women with previous GDM should be retested every three years for undiagnosed Type 2 diabetes". This periodicity was selected to retest for undiagnosed disease when the cumulative risk of developing diabetes had reached 5%. The time interval was selected on the basis of European studies.
In contrast, the ADIPS guidelines recommended testing every 1–2 years, but gave no reason for this, apart from the high risk of progression to diabetes among women of certain ethnic backgrounds who had had past GDM (as high as 47% over five years in Latino women5). A further, unstated reason for the 1–2-yearly testing was the major concern that fetal exposure to undiagnosed diabetes in any subsequent pregnancies could result in malformations.
The following has now been inserted into the draft Type 2 guidelines: 4 "The guideline conclusion to retest women with previous GDM every 3 years represents minimum criteria. More frequent retesting may be appropriate depending on clinical circumstances, especially during the child bearing years."
ADIPS supports this amendment fully and has revised its own guidelines in relation to maternal follow-up after GDM as follows:
All women with previous GDM to be offered testing for diabetes with a 75 g OGTT 6–8 weeks after delivery;
Repeat testing should be performed every 1–2 years among women with normal glucose tolerance and the potential for further pregnancies;
If pregnancy is not possible, follow-up testing should be performed every 3 years, with more frequent retesting depending on clinical circumstances (eg, ethnicity, past history of insulin treatment in pregnancy, recurrent episodes of GDM).
Differences between management guidelines for gestational diabetes mellitus (GDM) from the Australasian Diabetes in Pregnancy Society (ADIPS, 1998) and the American College of Obstetricians and Gynecologists (ACOG, 2001) [Table corrected on 27 August 2002.]
ADIPS |
ACOG |
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Universal versus selective screening by blood test |
Universal unless low GDM incidence or resources limited |
No recommendation. States that "many physicians elect to screen all pregnant patients as a practical matter" |
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Differences in definition of low risk for GDM |
Age < 30 years, obesity, family history of diabetes |
Age < 25 years, body mass index < 25 kg/m2. No known diabetes in first-degree relative |
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Oral glucose tolerance test used |
75 g, 2-hour, 2-point blood sampling |
100 g, 3-hour, 4-point blood sampling |
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Criteria for diagnosis of GDM |
Plasma glucose level: Fasting, ≥ 5.5 mmol/L and/or 2-hour, ≥ 8.0 mmol/L |
Plasma glucose level: Fasting, ≥ 5.3 mmol/L; |
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Insulin therapy commenced after medical–nutrition therapy |
Plasma glucose level: Fasting, ≥ 5.5 mmol/L and/or 1-hour postprandial, ≥ 8.0 mmol/L and/or 2-hour postprandial, ≥7.0 mmol/L |
Plasma glucose level: Fasting, ≥ 5.3 mmol/L and/or 1-hour postprandial, ≥ 7.2–7.8 mmol/L and/or 2-hour postprandial, ≥ 6.7 mmol/L |
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References
- Hoffman L, Nolan C, Wilson JD, et al. Gestational diabetes mellitus — management guidelines. The Australasian Diabetes in Pregnancy Society. Med J Aust 1998; 169: 93-97.
- American College of Obstetricians and Gynecologists. Clinical management guidelines for obstetrician–gynecologists: Gestational Diabetes. ACOG Practice Bull 2001; 30: 525-538. i1147031
- Oats J, McIntyre D, Morrison B, Parry A. Gestational diabetes randomised controlled trials: the HAPO (Hyperglycaemia and Adverse Pregnancy Outcome) Study. Australas Diabetes Pregnancy Soc Newsl 2001; February: 10-11. i1147033
- Australian Centre for Diabetes Strategies. National evidence based guidelines for the management of Type 2 diabetes mellitus: Public consultation draft. March 2000. Primary detection; Case detection and Diagnosis. Sydney: Australian Centre for Diabetes Strategies, 2000: 209. i1147035
- Kjos S, Peters RK, Xiang A, et al. Predicting future diabetes in Latino women with gestational diabetes. Utility of early postpartum glucose tolerance testing. Diabetes 1995; 44: 586-591. i1147037