Table 2.

Topics Explored in Interviews of Relevance to This Analysis

Background information and pretrial experiences

• Age, occupation, living arrangements, number, and age of other children.

• Diabetes duration; devices (e.g., pump, injections, CGM, and finger pricks) used pretrial.

• Views, hopes, and concerns about managing diabetes while pregnant and related pregnancy/health impacts.

• Experiences of managing diabetes during previous pregnancies (if any) and/or current pregnancy before joining the trial, including:

○ Regimen used (insulin administration and glucose monitoring); adjustments to basal rates/background and insulin-to-carbohydrate ratios; dietary choices and managing diabetes at mealtimes; undertaking physical activity; attainment of pregnancy glucose targets.

○ Management of and worries/concerns about hypo- and hyperglycemia.

Impact of regimen used on everyday life (e.g., sleep, work/family/social life) and overall pregnancy experience.

• Experiences of and views about receiving support from HCPs during previous pregnancies and/or pre-pregnancy planning.

Experiences of using the closed-loop system during the trial

• Experiences of initial training and education, learning to use and adapting to closed-loop; developing confidence and trust in closed-loop technology; any concerns about using closed-loop (and its components) during the trial.

• Experiences of and views about using the closed-loop to manage diabetes while pregnant, including:

○ Use of the app to inform decisions about diabetes management tasks (e.g., calculating/administering mealtime bolus doses, managing/treating hypo- and hyperglycemia).

○ Use of “Boost” and “Ease-off” functions; use of corrective doses of insulin.

○ Impact of closed-loop use when physically active.

○ Ability to attain (and maintain) pregnancy glucose targets.

○ Impact of closed-loop use on worries/concerns about hypo- and hyperglycemia.

○ Engagement with and access to insulin and glucose data through app on phone (and if and how this changed over time); which of the available data participants used; if/how data access affected how they managed diabetes.

○ Perceived impact of closed-loop use on everyday life (e.g., sleep, work/family/social life)

• Impact of closed-loop use on worries/concerns about managing diabetes while pregnant and related pregnancy/health outcomes.

• Experiences of and views about contact and support received from HCPs (e.g., mode and frequency of, and reasons for, contacts; impact of closed-loop use on participants' experience of health care encounters and interactions)

• Experiences of and views about health care teams having remote access to their real-time glucose and insulin data (e.g., concerns, perceived (dis)advantages).