The BP2 (Blood Pressure Postpartum) study: a 3-arm, randomised trial of follow-up and lifestyle behaviour change strategies in the first 12 months after hypertensive disorders of pregnancy

INTERVENTION: At 6 months postpartum (pp) all participants (women after preeclampsia, gestational hypertension, or chronic hypertension) complete validated questionnaires: NSW Population Health Survey (by telephone), Infant Feeding behaviours, Health‐related Quality of Life (EQ‐5D‐5L), Ages and Stages, Edinburgh Postnatal Depression Score, Generalised Anxiety Disorder and a study designed maternal and infant health questionnaire about health since the birth (hard copy or online). Pregnancy, labour, birth and infant details will be recorded from the hospital maternity database. Blood and urine testing will be done and repeated at 12 months pp. After completion of baseline questionnaires, women are randomised into one of 3 groups with interventions as below. Optimised Usual Care (Group 1): • report their weight, height, and waist circumference to the research staff • sent package containing readily available information about cardiovascular health after hypertensive disorder of pregnancy (HDP). This information includes: 1. The Heart Foundation infographic titled 'Did you have high blood pressure during pregnancy?'(www.heartfoundation.org.au), 2. The NSW Get Healthy Service (GHS) a free service of phone call counselling to work towards healthy lifestyle changes (www.gethealthynsw.com.au) 3. The link to the 'My Baby Now' app which is free and available on IoS and android phones. This app offers information regarding the baby's development and nutrition advice through to 9‐12 months of age. • visit their GP with their infant at 6 months pp for BP check, weight and their infant’s weight, height and head circumference. GP/medical centre will be sent an information package to assist with this visit. This package will contain an explanatory cover letter, correspondence from the pregnancy/birth care including the hospital discharge summary, the Heart Foundation Information for GPs titled 'Hypertensive Disorders of Pregnancy and Cardiovascular Disease: CONDITION: Cardiovascular ‐ Hypertension Preeclampsia;Gestational Hypertension;Chronic Hypertension in pregnancy; ; Preeclampsia ; Gestational Hypertension ; Chronic Hypertension in pregnancy Public Health ‐ Health promotion/education Reproductive Health and Childbirth ‐ Fetal medicine and complications of pregnancy PRIMARY OUTCOME: Change in systolic blood pressure measured using the average of three measurements from a validated automated blood pressure device; the Omron HEM‐907; ; ; [At 12 months postpartum (comparison between 6 month and 12 months postpartum values).] Maternal lifestyle behaviour change (LBC) as assessed by a decrease in waist circumference (2cm or more) measured with a measuring tape around the narrowest part of the torso.; [At 12 months postpartum (comparison between 6 month and 12 months postpartum values).] Maternal lifestyle behaviour change (LBC) as assessed by decrease in weight (4kg or more) measured by research staff using digital scales.[At 12 months postpartum (comparison between 6 month and 12 months postpartum values).; ; ] SECONDARY OUTCOME: Change in average blood pressure measured using the average of three measurements from a validated automated blood pressure device; the Omron HEM‐907 ; ; . ; ; [At 12 months postpartum (comparison between 6 month and 12 months postpartum values).] Lifestyle behaviour change measures assessed by the self‐reported NSW Population Health survey questions ; INCLUSION CRITERIA: Have given birth at one of the study hospitals during the study period. The index pregnancy was complicated by a hypertensive disorder of pregnancy: preeclampsia (PE), gestational hypertension (GH), chronic hypertension ± superimposed PE ; [At 12 months postpartum (comparison between 6 month and 12 months postpartum values).] Change in waist circumference. Waist circumference measured by researcher using measuring tape around the narrowest part of the participant's torso.[At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Change in weight. Weight measured by researcher using digital scales[At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Economic analysis ; A cost‐effectiveness analysis from the perspective of the healthcare system will be undertaken alongside the RCT. The primary economic outcome will be the incremental cost per case of BP and weight/waist circumference reduction achieved in Groups 2 and 3 during the study time period.[At 12 months postpartum ] Infant measures recorded in 'My Personal Health Record' (Blue Book): abdominal circumference[At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Infant measures recorded in 'My Personal Health Record' (Blue Book): head circumference[At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Infant measures recorded in 'My Personal Health Record' (Blue Book): height.[At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Infant measures recorded in 'My Personal Health Record' (Blue Book): weight. ; [At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal serological measures assessed by measuring CRP.[At 12 months postpartum (comparison between 6 month and 12 months postpartum values) ] Maternal serological measures assessed by measuring fasting cholesterol/triglyceride.[At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal serological measures assessed by measuring fasting insulin/glucose. ; [At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal serological measures assessed by measuring haemoglobin.[At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal serological measures assessed by measuring liver function.[At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal serological measures assessed by measuring platelets.[At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal urine measures assessed by measuring albumin:creatinine ratio. ; [At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal urine measures assessed by measuring eGFR [At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal vascular function measure performed using blood inflammatory cytokines[At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal vascular function measure: an ultrasound of the carotid arteries ; [At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal vascular function measure: augmentation index using SphygmoCor applanation tanometry, [At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal vascular function measure: pulse wave velocity using SphygmoCor applanation tanometry, [At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Maternal vascular function measures: central arterial pressure using SphygmoCor applanation tanometry, [At 12 months postpartum (comparison between 6 month and 12 months postpartum values). ] Women’s satisfaction with care measured using the self reported experience measure (PREM) incorporating elements of the Adherence to a Healthy Lifestyle, Burden of Treatment, and CSQ‐8 Client Satisfaction Questionnaire. ; [At 12 months postpartum (comparison between 6 month and 12 months postpartum values)] Women’s satisfaction with care: a qualitative study to explore women’s experience of each aspect of the interventions. Semi structured interviews will be conducted with women from all groups between the 6 and 12 month visits. These interviews will explore the barriers and enablers to adopting healthy eating and physical activity behaviours post‐partum and women will be asked their views of the intervention to better understand their engagement. All women will be invited to participate via a question at the end of the women’s 6 month survey and we will purposefully sample from each of the groups to ensure that views are captured about each arm of the intervention. Each interview will be digitally recorded (audio only) and later transcribed verbatim in preparation for a thematic analysis. [At 12 months postpartum]