St Mary's Assisted Reproductive Technology and Cardiometabolic Health: Modifiable Targets for Multimorbidity Prevention (START-HEALThY)

Objectives:

Primary objective: To assess the feasibility of a pre-conception and postnatal cardiometabolic health research study in infertile and fertile individuals.

Secondary objectives:

• To assess clinic-measured cardiometabolic status
• To measure ambulatory cardiovascular status
• To measure ambulatory blood glucose concentrations
• To assess the views of fertile and infertile individuals on cardiometabolic health optimisation and research in this area
• To assess acceptability of cardiometabolic status measurement approaches (clinic and ambulatory measured) in fertile and infertile populations
• To conduct initial exploratory investigations into whether cardiometabolic status is influenced by a history of infertility

Study Design This is a prospective observational cohort study consisting of two cohorts: a pre-conception cohort and a post-pregnancy cohort made up of individuals with and without a history of infertility. All participants of either cohort will have one research visit.

Individuals will be invited to attend a single face-to-face research appointment where the following will be undertaken:

• • Electronic wwritten consent will be obtained by a GCP-trained member of the clinical research team and a study number allocated.
• Optional consent will be obtained for access to medical records held at MFT (pertaining to any subsequent pregnancy and cardiometabolic outcomes, if in the pre-conception cohort) and to future data linkage studies related to future cardiometabolic health outcomes.
• Demographic data, medical history including cardiovascular/metabolic/obstetric/gynaecological history, medication history as well as mental health history, diet, breastfeeding, exercise, education and smoking status will be recorded.
• Anthropometric measurements, including height, weight, lean and fat mass (bioimpedance scale) and adiposity distribution (skin fold thickness), will be measured. BMI and waist-hip ratio will be calculated.
• Non-invasive assessments of cardiovascular function will be performed, including Mobil-O-Graph (pulse wave velocity, cardiac output, blood pressure, heart rate and total vascular resistance) using a blood pressure cuff, with or without EndoPAT 2000™ (endothelial function and vascular stiffness) via finger probes before and after occlusion with a blood pressure cuff.
• Blood samples (maximum 15ml of blood, equivalent to six teaspoons) for assessment of renal function, lipid levels and glucose control via HbA1C, will be collected by an appropriately trained member of the research team, analysed and clinically reported in line with routine clinical care.
• An ambulatory blood pressure monitor/pulse wave analyser (Mobil-O-Graph) will be fitted (if consent provided and a machine is available) and participants requested to wear this for 24 hours following the appointment, while conducting their daily activities. Once the Mobil-O-Graph device is returned the data will be downloaded by a member of the clinical research team and analysed.
• A continuous glucose monitor (CGM; FreeStyle Libre Pro IQ) will be fitted (if consent provided and a machine is available) and participants requested to wear for a minimum of 24-48 hours following the appointment, while conducting their daily activities (CGM data can be collected from a single sensor for up to 14 days). CGM data will be downloaded once the device is returned.

Participants will be asked to complete a post-participation questionnaire during the visit or via an email link sent to the participant after the visit, exploring:

• Views on cardiometabolic health optimisation
• Acceptability of the cardiometabolic health assessment, timing, approach to investigation and overall acceptability of participation

Analysis:

As this is a feasibility study, analysis will be through descriptive statistics (e.g., means/medians, standard deviations/interquartile ranges for continuous variables and frequencies and percentages for categorical variables) precision estimates (i.e., width of confidence interval).

We will conduct exploratory regression analyses to inform the design of adequately powered future studies.

Potential impact:

This study will assess the feasibility of recruiting individuals, with/without an infertility history, to a study of pre-conception and postnatal cardiometabolic status assessment. It will give initial indications of whether any difference in cardiometabolic health of infertile individuals pre-dates IVF treatment and/or persists or resolves in the short-term post-delivery. It will be the first to use ambulatory measures of cardiometabolic health (such as wearable blood pressure and glucose monitors), which may have increased sensitivity to detect subtle signs of (differences in) cardiometabolic (dys)function during normal activity, compared with single time point measures during clinical visits.

Ultimately, a better understanding of cardiometabolic dysfunction in infertile individuals may enable pre- or post- conception intervention (dietary, exercise and potentially pharmacological treatment) to optimise health before, during and after pregnancy in a life course approach to women's health (with anticipated positive impacts on the health of any resulting infant(s)).