Methodological quality of clinical practice guidelines for nutrition and weight gain during pregnancy: a systematic review

Context: Ensuring a healthy pregnancy and achieving optimal gestational weight gain (GWG) are important for maternal and child health. Nevertheless, the nutritional advice provided during pregnancy is often conflicting, suggesting limited adherence to clinical practice guidelines (CPGs). Objective: The aim of this review was to identify all CPGs on maternal nutrition and GWG and to critically appraise their methodological quality. Data Sources: The MEDLINE/PubMed, Cochrane, Guidelines International Network, and BMJ Best Practice databases, along with gray literature, were searched from inception until February 2019 for CPGs and consensus, position, and practice papers. Study Selection: Clinical practice guidelines published in English and containing advice on maternal nutrition or GWG were eligible. Data Extraction: Two authors independently extracted data on items pertaining to maternal nutrition or GWG, and CPGs were appraised using the AGREE II instrument. Results: Twenty-two CPGs were included. All scored adequately in the scope domain, but most were considered inadequate with regard to stakeholder involvement, rigor of development, applicability, and editorial independence. Many CPGs lacked patient or dietician involvement, and more than half did not disclose funding sources or conflicts of interest. Guidance on GWG was based mostly on Institute of Medicine thresholds, while nutrition recommendations appeared scattered and heterogeneous. Conclusion: Despite the importance of maternal nutrition and the plethora of advising bodies publishing relevant guidance, there is room for substantial improvement in terms of development standards and content of nutritional recommendations.