Diabetes Gestacional

Best Practice & Research Clinical Obstetrics and Gynaecology 25 (2011) 37–49

Contents lists available at ScienceDirect

Best Practice & Research Clinical Obstetrics and Gynaecology
journal homepage: www.elsevier.com/locate/bpobgyn

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Controversies in gestational diabetes
Christopher J. Nolan, BMedSci, MBBS, PhD, FRACP, Senior Specialist and Associate Professor *
Department ofEndocrinology and Diabetes, The Canberra Hospital, and the Australian National University Medical School, Canberra, ACT, Australia

Keywords: gestational diabetes mellitus maternal metabolic syndrome maternal obesity screening and diagnosis goals of management short- and long-term outcomes

Gestational diabetes mellitus (GDM) and controversy are old friends. However, several major studies in the fieldhave clarified some of the main issues. There is now no doubt that hyperglycaemia, at levels less than those that occur in overt diabetes, is associated with adverse pregnancy outcomes, such as large-for-gestational age infants, neonatal hyperinsulinism, neonatal hypoglycaemia and preeclampsia. We also have evidence now that a standard approach to GDM with diagnosis at 24–28 weeks, dietary advice,self-monitoring of blood glucose and insulin therapy as needed reduces these adverse perinatal outcomes. Unknown, however, is if this same approach is effective at reducing long-term risks of metabolic syndrome, type 2 diabetes and cardiovascular disease in both the mothers and babies. For example, could our management strategies miss critical time points of fuel-mediated injury to the foetusimportant for the baby’s long-term metabolic health? The implications of a recent international consensus statement on new diagnostic criteria for GDM are discussed, as well as issues relating to the timing of diagnosis. The potential place for a risk calculator for adverse outcomes in GDM pregnancy that takes into account glycaemic and non-glycaemic risk factors is considered. Such a tool could helpstratify GDM women to different levels of care. Ongoing issues relating to maternal glycaemic and foetal growth targets, and the use of oral hypoglycaemic agents in GDM are discussed. To resolve some of the remaining controversies, further carefully designed randomised controlled trials in GDM with long-term follow-up of both mothers and babies are necessary. Ó 2010 Elsevier Ltd. All rightsreserved.

* Corresponding author: Department of Endocrinology and Diabetes, The Canberra Hospital, PO Box 11, Woden, ACT 2606, Australia, Tel.: þ61 2 62442228; Fax: þ61 2 62444616. E-mail address: christopher.nolan@anu.edu.au. 1521-6934/$ – see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.bpobgyn.2010.10.004

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C.J. Nolan / Best Practice & Research Clinical Obstetricsand Gynaecology 25 (2011) 37–49

Gestational diabetes mellitus (GDM) is defined as “glucose intolerance with onset or first recognition in pregnancy” or “carbohydrate intolerance of varying severity which is diagnosed in pregnancy and may or may not resolve after pregnancy.”1–5 Controversy and GDM have always co-existed.6,7 This dates back as far as 1964 when O’Sullivan and Mahan first proposedspecific criteria for interpreting the oral glucose tolerance in pregnancy.8 The fact that GDM is a very strong risk factor for subsequent permanent diabetes development in the mother has never been a point of contention.9,10 The controversy has centred around two questions: (1) Does the maternal hyperglycaemia of GDM pregnancies, independently of associated factors such as obesity and higher maternalage, contribute to adverse pregnancy outcomes? (2) Does the diagnosis and treatment of GDM improve pregnancy outcomes? Recently, there has been substantial progress in resolving these areas of controversy by major studies in the field. The Hyperglycaemia and Adverse Pregnancy Outcomes (HAPO) study, a major international observational study of pregnant women, showed without doubt that maternal...