Designing and developing a physical activity intervention for women with gestational diabetes mellitus using the behaviour change wheel

  • Medbh Hillyard

Student thesis: Doctoral Thesis


Physical activity (PA) levels in pregnancy are known to decrease despite the numerous known benefits for both mother and baby. Due to the potential to improve blood glucose control, the gains from physical activity are particularly important for women with Gestational Diabetes Mellitus (GDM). Behaviour change theories have been sparsely used to develop lifestyle interventions to increase PA in women with GDM. Therefore, this study used Michie et al.’s (2014) Behaviour Change Wheel combined with input from women who had experienced pregnancy with GDM to develop a motivationally enhanced lifestyle intervention to increase PA and reduce sedentary behaviour.

A mixed methods study was undertaken employing an explanatory sequential design. Phase one was a systematic review and meta-analysis exploring the effect of PA and dietary interventions on maternal and fetal outcomes. Phase two led on from the review and explored the experience of six women who have had GDM. These two phases provided the evidence base for the development of a lifestyle intervention for women with GDM in phase three. The Behaviour Change Wheel (BCW) was used to systematically design the intervention. The final phase was an alternative phase four due to the COVID-19 pandemic and involved investigating the effects the COVID-19 pandemic had on the activity levels of women with GDM. This was done through a UK wide, online survey of 553 women.

The systematic review demonstrated PA had the potential to reduce the need for exogenous insulin in women with GDM, however it did not affect birth weight or number of caesarean sections. Women who had experienced GDM described their memories of feeling overburdened, lacking support and facing many unexpected challenges. Women lacked opportunities and the physical and psychological capabilities to be physically active. Phase three resulted in the development of a
lifestyle intervention for women with GDM, designed using the Behaviour Change Wheel. The survey found that women’s PA levels reduced by 50% during the pandemic and 79% of women reported increasing their sedentary time. Phase four highlighted the considerable impact the COVID-19 pandemic has had on the activity levels of women with GDM.

PA has been found to reduce the need for insulin and is worth incorporating into the pregnancy care plan for women with GDM. The results from the interviews demonstrated that women with GDM need practical and professional support to manage the challenges of living with GDM. This PhD has resulted in the development of a theoretically underpinned lifestyle intervention for women with GDM, which aimed to increase the PA levels and reduce sedentary behaviour whilst also providing social support. To the best of the researcher’s knowledge this is the first intervention of its kind to combine these three elements, whilst designing a theoretically underpinned intervention for women
with GDM.
Date of AwardMay 2021
Original languageEnglish
SupervisorKaren Casson (Supervisor), Marlene Sinclair (Supervisor) & Marie Murphy (Supervisor)


  • Sedentary behaviour
  • COM-B
  • COVID-19

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