Dietary recommendations for women with gestational diabetes mellitus: a systematic review of clinical practice guidelines

Context: Dietary advice is the cornerstone of care for women with gestational diabetes mellitus (GDM) to improve maternal and infant health. Objectives: This study aimed to compare dietary recommendations made in clinical practice guidelines (CPGs) for the management of GDM, evaluate their evidence base, identify research gaps, and assess CPG quality. The PRISMA guidelines were used. Data Sources: Six databases were searched for CPGs, published between 2000 and 2019, that included dietary advice for the management of GDM. Data Extraction: Two reviewers independently assessed CPG quality (using the AGREE II tool) with respect to dietary recommendations (their strength, evidence base, and research gaps). Data Analysis: Of the 31 CPGs, 68% were assessed as low quality, mainly due to lack of editorial independence. Dietary advice was recommended as the first-line treatment by all CPGs, although the dietary recommendations themselves varied and sometimes were contradictory. Most dietary recommendations were strongly made (70%), but they were often based on very low-quality (54%), or low-quality (15%) evidence. Research gaps were identified for all diet-related recommendations. Conclusion: High-quality research is needed to improve the evidence base and address the research gaps identified.