Revision of guidelines for the management of gestational diabetes mellitus

To the Editor: Consensus guidelines for the management of gestational diabetes mellitus (GDM) were prepared by the Australasian Diabetes in Pregnancy Society in 1997–1998 and subsequently published in the Journal.1

Since that time, there have been two minor revisions to these guidelines. The first, in relation to the recommended frequency of follow-up testing of women identified as having GDM, was detailed in a letter to the Editor in 2002.2

The second concerns the timing of delivery of women with GDM. At the request of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG), the original recommendation that “continuation of the pregnancy in uncomplicated GDM to 10 days beyond term is acceptable provided that indications from fetal monitoring are reassuring” has been modified by replacing “10 days beyond term” with “full term” to bring this into line with current practice.

The initial guidelines were arrived at by consensus of Australasian practitioners involved in the care of women with GDM. The Australasian Diabetes in Pregnancy Society recognised, both at the time and subsequently, that the level of evidence available to guide clinical decision-making fell well short of that necessary for a definitive statement on the timing of delivery.

It is noteworthy that no international consensus exists concerning the optimal timing of delivery in pregnancies complicated by GDM. The American Diabetes Association, in its Clinical Practice Guidelines, recommends delivery “during the 38th week . . . unless obstetric considerations dictate otherwise”.3 The European Association of Perinatal Medicine does not make a recommendation, instead stating that “the optimal time of delivery and need to induce labour are still controversial.”4

There is currently a paucity of quality evidence on which to confidently base recommendations. We hope that current studies, such as the Australian Carbohydrate Intolerance in Pregnancy Study and the Hyperglycemia and Adverse Pregnancy Outcome Study,5 will provide this evidence.