BackgroundObesity during pregnancy is associated with increased risk of gestational diabetes mellitus (GDM) and other complications. Physical activity is a modifiable lifestyle factor that may help to prevent these complications but many women reduce their physical activity levels during pregnancy. Interventions targeting physical activity in pregnancy are on-going but few identify the underlying behaviour change mechanisms by which the intervention is expected to work. To enhance intervention effectiveness, recent tools in behavioural science such as the Theoretical Domains Framework (TDF) and COM-B model (capability, opportunity, motivation and behaviour) have been employed to understand behaviours for intervention development. Using these behaviour change methods, this study aimed to identify the enablers and barriers to physical activity in overweight and obese pregnant women.MethodsSemi-structured interviews were conducted with a purposive sample of overweight and obese women at different stages of pregnancy attending a public antenatal clinic in a large academic maternity hospital in Cork, Ireland. Interviews were recorded and transcribed into NVivo V.10 software. Data analysis followed the framework approach, drawing on the TDF and the COM-B model.ResultsTwenty one themes were identified and these mapped directly on to the COM-B model of behaviour change and ten of the TDF domains. Having the social opportunity to engage in physical activity was identified as an enabler; pregnant women suggested being active was easier when supported by their partners. Knowledge was a commonly reported barrier with women lacking information on safe activities during pregnancy and describing the information received from their midwife as ‘limited’. Having the physical capability and physical opportunity to carry out physical activity were also identified as barriers; experiencing pain, a lack of time, having other children, and working prevented women from being active.ConclusionA wide range of barriers and enablers were identified which influenced women’s capability, motivation and opportunity to engage in physical activity with “knowledge” as the most commonly reported barrier. This study is a theoretical starting point in making a ‘behavioural diagnoses’ and the results will be used to inform the development of an intervention to increase physical activity levels among overweight and obese pregnant women.Electronic supplementary materialThe online version of this article (10.1186/s12884-018-1816-z) contains supplementary material, which is available to authorized users.

Maternal obesity is associated with increased risk of gestational diabetes and other complications. Although antenatal interventions to help prevent these complications are ongoing, an understanding of overweight and obese pregnant women's opinions and attitudes is lacking. Therefore, this study aims to explore these women's experiences and perceptions of dietary behaviours and weight management during pregnancy. Secondary analysis of qualitative data originally collected to examine lifestyle behaviours in pregnant women was conducted. The data were from a purposive sample of overweight and obese pregnant women attending a public antenatal clinic in Cork, Ireland. The data were explored using thematic analysis. Interviews with 30 overweight and obese pregnant women were analysed. Three themes were developed relating to overweight and obese women's dietary behaviours and weight management perceptions including ‘pregnancy's influence on dietary behaviours’, ‘external influences on dietary behaviours’ and ‘perception of and preferences for weight related advice and resources’. Together these themes reveal women's experiences of diet and how pregnancy factors (physiological changes) and external factors (family and friends) can influence dietary behaviours. Furthermore, perceptions of weight management advice and lack thereof were highlighted with women drawing attention to potential resources for future use during pregnancy. This study provides important insights into overweight and obese pregnant women's dietary behaviours and perceptions of weight management. According to these findings, there is a need for clear and unambiguous information about weight management, acceptable weight gain, food safety and how to achieve a balanced diet.