Unhealthy weight gain in pregnancy is common in Aotearoa/New Zealand (up to 70% of pregnant women). It increases the risk of adverse outcomes e.g. gestational diabetes and large for gestational age babies. We have developed, and assessed the feasibility of a midwife-delivered optimal weight gain in pregnancy intervention (DOT) to guide dietary advice as part of routine antenatal care to limit the proportion of pregnant women gaining excess weight, whilst not increasing the proportion who gain insufficient weight. In this Northland initiated study, our research activation (HRC20/974) has informed, and will facilitate a case study with Lead Maternity Carer midwives and pregnant women to assess acceptability, accessibility and impact of our pragmatic midwife-delivered intervention in a real-world setting, with a specific focus on improving Māori health outcomes. Factors that influenced implementation and delivery of the intervention, specifically its workability and integration into practice will be described, informing policy and practice.