Abstract
AIMS/HYPOTHESIS: The aim of this study was to develop a core outcome set (COS) for trials and other studies evaluating the effectiveness of prepregnancy care for women with pregestational (pre-existing) diabetes mellitus. METHODS: A systematic literature review was completed to identify all outcomes reported in prior studies in this area. Key stakeholders then prioritised these outcomes using a Delphi study. The list of outcomes included in the final COS were finalised at a face-to-face consensus meeting. RESULTS: In total, 17 outcomes were selected and agreed on for inclusion in the final COS. These outcomes were grouped under three domains: measures of pregnancy preparation (n = 9), neonatal outcomes (n = 6) and maternal outcomes (n = 2). CONCLUSIONS/INTERPRETATION: This study identified a COS essential for studies evaluating prepregnancy care for women with pregestational diabetes. It is advocated that all trials and other non-randomised studies and audits in this area use this COS with the aim of improving transparency and the ability to compare and combine future studies with greater ease.