This presentation will briefly cover breast anatomy and the physiology of lactation, and provide evidence of the importance of breastfeeding for maternal health, with a focus on women with diabetes in pregnancy. The DAME trial investigated whether antenatal expressing was safe and effective for women with diabetes in pregnancy. We found the practice of expressing breastmilk from 36 weeks' gestation was safe for women at low risk of complications. However, while increased exclusivity of breastmilk feeding was seen in hospital, there was no evidence of difference in infant feeding at later follow-up. We confirmed that secretory activation (lactogenesis II) was later in women with diabetes in pregnancy than in a contemporaneous cohort without diabetes. Although antenatal expressing had been thought to hasten lactogenesis, we found no evidence of difference in the DAME participants. New research projects will be introduced. 1. A pilot study in Brazil explored proactive postnatal milk expressing as a technique to improve exclusivity of breastmilk feeding. 2. A new RCT is using pasteurized donor milk for term infants of mothers with diabetes (PRESENT).