Maternal obesity increases risks for the mother and her child. It is crucial to arouse the pregnant and postpartum women´s willingness of change and motivation to take care of their own and their unborn child´s health. Researchers have suggested that reﬁning the pre-existing prenatal care models, possibly incorporating diet and physical activity into interventions, could be useful. Continuous monitoring can provide real-time information between scheduled appointments and thus may be helpful for targeting and tailoring pregnancy follow-up. Wearable devices can be helpful for weight-management, e.g. in improving participant's self-efficacy in making healthy behavior changes, improving self-awareness, in goal setting and getting feedback. However, it's very important to identify and tailor the intervention into individual motivations in order to facilitate technology adoption. Technological solutions designed for the pregnant women, can balance the gap between limited resources and growing demand of maternity care service. More comprehensive research is required to implement the optimal weight-management intervention for overweight women during pregnancy and the postpartum period and to develop appropriate and feasible implementation strategies to support nurses to deliver interventions in maternity clinics.

The aim of this study is to evaluate the effectiveness of the Supporting Lifestyle Change in Obese Pregnant Mothers Through Wearable Internet-of-Things (SLIM) intervention. Secondary aim is to evaluate the implementation of SLIM intervention in maternity care.

Intervention was developed based on findings of overweight women and their care givers interview study. In addition, intervention was planned in collaboration with public health nurses working in maternity clinics in workshops. The intervention targeting overweight pregnant women to improve their weight-management will be delivered during routine perinatal visits from the first visit to three months after child birth. Interventions core components will be goalsetting, motivational interviewing, feedback and health technology. Health technology includes Oura-ring and ZotCare -application. ZotCare -application combines data from Oura Smart Ring, electronic food diary and it´s also platform for researchers to send e.g. questionnaires and surveys to participants. Oura-smartring is an advanced technology ring that monitors e.g. heart rate, heart rate variability (HRV), steps, body temperature and sleep) and a smartphone application that includes data from Oura, and electronic food diary. Data collected with Oura -smartrings will be transmitted to cloud servers via a smartphone. The cloud will be responsible for storing the data and for performing the data preprocessing and analysis methods. Interventions primary outcome will be self-efficacy. Secondary outcomes will be womens weight, depression symptoms, quality of life and sence of coherence.

Data will be collected via Oura smartring, electronic food diary and validated measures: Weight Efficacy Life-Style Questionnaire (WEL), Self-Efficacy for Physical Activity Scale (PASE), six-factor questionnaire (6-FQ), Three Factor Eating Questionnaire (TFEQ-R18), WHOQOL-BREF, Sense of coherence (SOC-13), Pregnancy anxiety (PRAQ-R2), Perceived stress and Edinburgh Postnatal Depression scale (EPDS). Intervention implementation will be evaluated with process evaluation. Interventions acceptability, appropriateness and feasibility will be assessed with validated measures: Acceptability of Intervention Measure (AIM), Intervention Appropriateness Measure (IAM), and Feasibility of Intervention Measure (FIM). Data will be collected from public health nurses working in maternity clinics using focus group interviews and workshops.