Objective: The Postnatal Wellbeing in Transition (PostTrans) Questionnaire assesses psychosocial wellbeing among women transitioning to motherhood while managing pre-existing diabetes. Face and content validity have been previously reported; however the PostTrans questionnaire has 51 items which imposes a substantial burden on respondents. The aim of this study was exploratory analysis of the PostTrans questionnaire to investigate whether a reduction in the number of items was statistically supported, and whether clinically meaningful subscales could be derived. Methods: A prospective cohort of women with type 1 or type 2 diabetes was recruited from three metropolitan hospitals in Melbourne, Australia. Women completed surveys across three postnatal time points. Data were pooled for the analysis. Suitability for factor analysis was confirmed and exploratory Principal Components Analysis with oblique rotation was conducted. Results: The number of responses in the pooled dataset was 117. The reduced PostTrans scale has 27 items and six factors, which together explain 68.7% of the variance. The subscales assess: feeling as if one is coping with diabetes and the infant; feeling anxious and guilty about diabetes; feeling supported by family; sensitivity to the opinions of others; prioritising self-care; and health professional support. Conclusion: The number of items in the PostTrans Questionnaire was reduced from 51 to 27 items. Six meaningful subscales emerged, which can help health professionals identify and address areas in which women with diabetes are experiencing psychosocial difficulties. The revised scale provides a feasible instrument to be tested for psychometric properties in a larger sample.