Title: A two arm feasibility trial of lifestyle information and Slimming World groups to promote weight management and positive lifestyle behaviour in postnatal women from an ethnically diverse inner city population
Funder: Department of Health and Social Care

Abstract: Research question: Is it feasible to conduct a definitive randomised controlled trial (RCT) of lifestyle information and access to Slimming World groups designed to achieve and maintain healthy weight and positive lifestyle behaviour in postnatal women most at risk of weight retention in an inner city population? Study design: Two arm feasibility RCT to inform need, design, processes and outcomes for a definitive RCT. Participants: 190 women aged >18, with a single pregnancy, who can understand English and have not accessed weight management programmes in their current pregnancy. Obese (Body Mass Index (BMI) >30 kg/m²) or overweight(BMI 25–29.9 kg/m² women at antenatal booking and women with normal booking BMI but excessive gestational weight gain (GWG) as defined by the Institute of Medicine will be recruited and randomised at 36 weeks gestation to intervention or standard care only. Intervention: Standard care and positive lifestyle information and postnatal access to Slimming World groups underpinned by relevant evidence. Benefit of group based weight management programmes has been shown in general population studies but has not been previously considered for weight management in postnatal women. How to influence positive lifestyle behaviours has also not been considered in this population. Women will receive a positive lifestyle leaflet at recruitment, the content reflecting current public health guidance on breastfeeding, diet, smoking cessation, alcohol advice and sleep guidance. From 8 weeks postnatally, women can access Slimming World groups for 12 consecutive weeks, with option to commence a group up to 16 weeks after giving birth. Slimming World will waive group membership fees, to promote equity of access in a diverse inner city population. Control women will receive standard care only. Quantitative outcomes to support a definitive RCT powered to detect significant changes in variables related to postnatal weight management will include: proportion eligible who consent/refuse; time to recruit, proportion ineligible; reasons for refusing; contamination rate; retention/adherence; loss to follow up; missing data; potential adverse events. This study will not be powered to detect significant effects of the intervention on change in body weight. Our primary assessment, likely to be used in a definitive trial, is difference between trial arms in weight 12 months postnatally, expressed as percentage change from weight recorded at the woman's first antenatal appointment. Analysis will be by intention to treat (ITT). Pre-planned subgroup analysis will look at primary outcome in different pre-pregnancy BMI categories. Secondary assessments will include: percentages of women meeting weight reduction of 5% and 10%; breastfeeding uptake/duration; smoking status; alcohol use; diet and nutrition; physical activity; mental & physical health; body image; self-esteem; health-related quality of life; and resource impacts. Process evaluation will assess acceptability of study procedures and experience of the intervention by asking women in follow-up questionnaires and semi-structured telephone interventions with a purposive sample of control and intervention group women (n=15-20) and purposive sample of women on completing Slimming World groups (n=10). Variation in characteristics of Slimming World groups attended will be collated and triangulated with data from women to aid interpretation of findings.

Lay abstract: Many women are overweight or obese when they become pregnant, or gain more weight in their pregnancy than they need to. These women are more likely to suffer problems such as diabetes or high blood pressure, to need interventions during birth and are less likely to breastfeed. They are also more likely to have ongoing weight problems, increasing the risk of poor outcomes in future pregnancies and of long term health conditions such a heart disease. Babies born to women who are overweight or obese are more likely to have heavier birthweight, congenital birth defects, to be stillborn or to become obese themselves. Women who live in disadvantaged communities are more likely to have weight management problems. Developing good quality postnatal advice on diet and lifestyle is an important way of supporting women and their families in these communities. However, it still is unclear how or when to engage women and how best to support them with weight management. We want to study if attendance at Slimming World groups, supported by good quality information on healthy lifestyles, could support women in a deprived inner city population to better manage their postnatal weight and to take up more positive health behaviours, such as breastfeeding, increasing physical activity and stopping smoking. Firstly, we need to conduct a ‘feasibility study’, which will provide information as to whether running a much larger scale study is likely to succeed. This will enable us to see if women would take part in a study where they will be randomly selected to the Slimming World (intervention) or usual care only (control) groups. We want to know how many eligible women could be recruited, and how long it would take to recruit the numbers we need; if it is possible to weigh women who are normal weight at the start of pregnancy later in their pregnancy to measure weight gain during pregnancy; if women would be willing to be randomised; when best to start postnatal weight-management; if women would stick to their groups (i.e. attend Slimming World groups if randomised to the intervention group and not attend if randomised to the control group); what effect the intervention has on outcomes that may be important; and what value is provided by the lifestyle information leaflet. The intervention will be the group version of Slimming World, as there is evidence that weight management groups work. We will recruit women at 36 weeks of pregnancy who were overweight or obese at the start of pregnancy or gain more weight during pregnancy than they need to. A Research Midwife will provide women in the intervention group with a positive lifestyle leaflet giving advice on health behaviours from 36 weeks to 8 weeks postnatally (when maternity care ends) and offer free access to a local Slimming World group. Women will be able to choose the time and location of the group, and will be able to join the group anytime from 8 weeks up to 16 weeks after birth. Women in the control group will receive usual care. At the time of recruitment, and at 6 and 12 months after birth, all women will asked to complete a questionnaire (which will be sent by post/email at 6 and 12 months) to complete, for example, on weight management, diet, lifestyle, and infant feeding. They will also be asked to attend an appointment to be weighed by the Research Midwife and some may be invited to take part in interviews with a member of the research team.

Research activity codes: 3.1 PRIMARY PREVENTION INTERVENTIONS TO MODIFY BEHAVIOURS OR PROMOTE WELL-BEING
Health categories: CANCER AND NEOPLASMS;CARDIOVASCULAR;METABOLIC AND ENDOCRINE;ORAL AND GASTROINTESTINAL;STROKE