Maternal Diet in Pregnancy in Women with Gestational Diabetes

Abstract

Aim: Gestational diabetes mellitus (GDM) is carbohydrate intolerance that occurs during pregnancy. GDM can increase the risk of adverse maternal and infant health outcomes. We aimed to explore the current dietary management for women with GDM and investigate the influence of maternal dietary adherence on maternal and infant health outcomes. Methods: Firstly, we conducted a systematic review of the global clinical practice guideline (CPG) dietary recommendations for the management of GDM. The quality of the CPGs, dietary recommendations and evidence-base were assessed, and any research gaps identified. Secondly, we conducted a cohort study to investigate maternal adherence to the New Zealand dietary CPG recommendations for the management of GDM and assessed the association of maternal sociodemographic factors on dietary adherence. Lastly, we conducted a cohort study to explore the influence of maternal dietary adherence on maternal and infant health outcomes. Findings: Results from our systematic review showed that dietary intervention was recommended as the firstline therapy for GDM management globally, but dietary recommendations were inconsistent across CPGs. Most CPGs were of low-quality, the quality of evidence was low or very-low quality, and several research gaps were identified. Our cohort study reported that no-one adhered to all dietary recommendations for GDM management in New Zealand, while 86% of women visited a dietitian but only 28% achieved appropriate weight gain. Primiparity, no history of GDM, being underweight, and smoking were associated with lower dietary adherence. We found that high dietary adherence compared to low adherence was associated with reduced use of oral hypoglycaemics and insulin. Visiting a dietitian compared to no visit was associated with increased oral hypoglycaemic and insulin use, but decreased odds of a large-for-gestational-age infant and neonatal hyperbilirubinaemia. Greater than recommended weight gain compared to appropriate weight gain was associated with increased maternal oral hypoglycaemic and insulin use, while gaining lower than recommended weight was associated with increased odds of breastfeeding and decreased postpartum haemorrhage. Conclusion: High-quality CPGs and better evidence are needed to improve the management of GDM and address the research gaps identified. Further research should identify appropriate ways to increase dietary adherence for women with GDM.