The principles of dietary management of gestational diabetes: reflection on current evidence

Background Gestational diabetes (GDM) is the commonest metabolic disorder of pregnancy. Most women with GDM are treated with nutritional management alone. There are conflicting guidelines surrounding its dietary management and this has resulted in a lack of conformity to the dietary advice currently prescribed. There is also conflicting opinions to the effectiveness of dietary management of GDM on pregnancy outcomes. The aim of this review was to examine the scientific evidence for the optimal nutritional management of GDM. Methods A Medline search of all English papers published between 1995 and 2001 that cross-referenced GDM with diet was under taken. Because of the poor quality of many of these papers, literature prior to 1995 known to the authors and considered relevant to the review were also included. Results The evidence base in this area is of poor quality. One systematic review based on randomized control trials failed to show any benefit from dietary intervention in GDM. However, that review did not include informative clinical and observational studies that are not classified as randomized controlled trials. Overall current evidence points to the effectiveness of dietary advice as a means of improving maternal hyperglycaemia and reducing the risk of accelerated foetal growth. The evidence surrounding energy restriction, carbohydrate and fat manipulation in GDM remains controversial. Conclusions Current but limited evidence supports dietary alterations to reduce rates of accelerated foetal growth. There is a clear need for good quality randomized control trials in this area.