The effect of pre-pregnancy dietary advice and regular exercise to promote health in women with BMI between 18.5 and 24.9kg/m2, on pregnancy outcomes: the Begin Better 2.0 randomised trial.

Women randomised to the Lifestyle Intervention Group will receive verbal advice based on current RACGP's guideline (2021) on Preventative activities prior to pregnancy. Participants will be offered a one-on-one appointment with the registered Midwife (face-to-face, by phone or virtual) for between 30-60 minutes within the first 4 weeks of the study. Information will be provided to encourage women to stop smoking and use of illicit substances, limit alcohol intake, commence folate supplementation, and ensure immunisations (particularly rubella) and cervical cytology are current, consistent with best clinical practice. The comprehensive Dietitian prescribed intervention will combine dietary, exercise and behavioural strategies to promote optimal pre-conception health. The participants will attend one appointment with a study Dietitian for up to 60 minutes, within the first 4 weeks of the intervention. This appointment will be one-on-one and may be face-to-face, by phone or virtual. This appointment will include an assessment of food frequency questionnaire, as well as comprehensive questions about general health and lifestyle, social and environmental factors, diet history and physical activity habits. Individual health goal setting is also discussed. Behavioural Goals We will encourage and support behavioural strategies to increase physical activity and improve diet. Dietary Goals Dietary advice will be Dietitian prescribed, consistent with current Australian dietary guidelines and the Australian guide to healthy eating. The dietary intervention will be individualised for each woman. Physical Activity Goals Women will be instructed to increase or maintain optimal physical activity by their health coach to meet the recommendations of Australia’s Physical Activity & Sedentary Behaviour Guidelines for Adults. The current guidelines suggest women should aim for 150 to 300 minutes of moderate physical activity per week OR 75 to 150 minutes of vigorous physical activity per week AND Muscle strengthening activities on at least 2 days each week. Health management Strategies will promote ongoing healthy dietary and physical behaviours, and will involve regular ongoing face to face, telephone and SMS health coaching with research staff. Staff are tertiary qualified in the areas of health and nutrition, and will be trained by a clinical psychologist on motivational interviewing principles and techniques. The research staff conducting health coaching are not the same as the Midwife or the Dietitian. Adherence to diet and physical activity advice will be assessed by food frequency and physical activity questionnaires at the commencement and completion of the intervention period. Further information about this intervention is available from the trial contact staff named in this registration.