Predicting dysglycaemia in individuals with gestational diabetes immediately postpartum using continuous glucose monitoring (PREDISPOSE) in a multicentre prospective cohort study in Canada: a study protocol.

introductionGestational diabetes is a common metabolic disorder in pregnancy which identifies a substantial increased risk of future diabetes. Despite this risk, many individuals are not screened for dysglycaemia in the postpartum period. Continuous glucose monitoring (CGM) is an evolving technology that provides details of an individual's glucose levels throughout the day; however, it has not yet been evaluated as a screening tool for postpartum dysglycaemia. To address this gap, this prospective cohort study will examine the use of CGM in the early postpartum period to predict the risk of maternal dysglycaemia after delivery. METHODS AND ANALYSIS: The Predicting Dysglycaemia in Individuals with Gestational Diabetes Immediately Postpartum using CGM (PREDISPOSE) study is a prospective cohort study designed to assess the ability of a CGM device (Freestyle Libre 2) worn in the postpartum period to detect persistent dysglycaemia in individuals with gestational diabetes. The study will recruit 240 individuals with gestational diabetes. Each participant will wear the CGM immediately postpartum and before attending routine postpartum diabetes screening, consisting of a 75-gram oral glucose tolerance test (OGTT) and related blood work (haemoglobin A1c (HbA1c), complete blood count and lipid profile). The primary outcome is the accuracy of the area under the curve for all glucose measurements from the first CGM wear to detect postpartum dysglycaemia. We will perform sensitivity and specificity analyses to determine optimal CGM cut-offs to diagnose diabetes or prediabetes. Secondary outcomes include the incidence of postpartum dysglycaemia (based on 75-gram OGTT and/or HbA1c), incidence of postpartum dyslipidaemia, patient acceptability of CGM testing, data variability from CGM and cardiometabolic health outcomes diagnosed in years one, two and five after delivery. ETHICS AND DISSEMINATION: All participating sites have received ethics approval of the current protocol and have started recruitment of participants to the study. The ethics boards that approved this study are the Biomedical Research Ethics Board at the University of Manitoba, the Conjoint Health Research Ethics Board at the University of Calgary, the Mount Sinai Hospital Research Ethics Board at Mount Sinai Hospital and the Comité d'éthique de la Recherche at Université Laval. Study results will be disseminated through conference presentations and publication in a peer-reviewed journal, regardless of study findings. TRIAL REGISTRATION NUMBER: NCT04972955. Registration date: 28 June 2021.