Factors influencing infant feeding practices in women with type 1 diabetes mellitus in pregnancy: a systematic review

Abstract Aims Women with Type 1 diabetes experience physiological, psychosocial, and healthcare-related challenges during the perinatal period that may affect infant feeding outcomes. This systematic review aimed to synthesise evidence on factors influencing breastfeeding and other infant feeding practices among women with Type 1 diabetes. Methods This review followed PRISMA guidelines. Eligible studies included qualitative, quantitative, or mixed-methods designs involving pregnant women with Type 1 diabetes and reporting factors influencing breastfeeding, formula feeding, or mixed feeding. Embase, MEDLINE, CINAHL, and MIDIRS were searched (1974–2025). Study quality was appraised using the Mixed Methods Appraisal Tool. Data were extracted and narratively synthesised. Results 15 studies were included (10 quantitative, 5 qualitative). In adjusted analyses, intention to breastfeed exclusively and prior breastfeeding experience were associated with higher odds of breastfeeding initiation and exclusivity. Lower maternal BMI was associated with higher odds of initiation, while higher education was associated with higher odds of exclusivity. Neonatal hypoglycaemia and non-White ethnicity were associated with lower odds of exclusivity. Smoking during pregnancy and infant hospitalisation during the first year were associated with earlier breastfeeding cessation, whereas older maternal age and higher birthweight were associated with longer duration. Unadjusted and qualitative evidence described neonatal-unit admission or mother-infant separation, perceived insufficient milk supply, maternal glycaemic instability, and inconsistent diabetes-informed support. Reporting of donor human milk, formula or mixed feeding, and glycaemic-control technologies was limited. Conclusions Evidence on infant feeding practices among women with Type 1 diabetes is limited and heterogeneous. Care should offer diabetes-aware lactation support from pregnancy through the early postnatal period, minimise avoidable separation, and prioritise the mother’s own milk, with donor human milk preferred over formula where safe and available. Future research should characterise formula/mixed feeding patterns, and evaluate how diabetes technologies affect feeding outcomes. Clinical trial number Not applicable.