The aim of this study was to explore the development over time of beliefs about  health, illness and health care in migrant women with gestational diabetes mellitus born in the Middle East and living in Sweden. Further to study the influence of beliefs on self-care and care seeking behaviour. There is an extensive global migration and contact with the new society and health care confronts the migrant's culture of origin with the culture of the host country. The question is whether the migrants' patterns of beliefs about health, illness and health-related behaviour change over time? 

A qualitative prospective exploratory study was implemented. Semi-structured interviews were held with 14 women, aged 28-44 years, in gestational weeks 34-38 and three and 14  months after delivery.

The results showed a U-shaped development of beliefs, from focusing on worries about the baby's health during pregnancy and trying to comply with advice from health care staff, particularly a healthy diet, through regression to dietary habits (with intake of more sugar and less fibre) and lifestyle held before being diagnosed with gestational diabetes mellitus three months after delivery but then back to a healthy diet and lifestyle and worries focusing on their own risk, as mothers, of developing type 2 diabetes and being unable to care for the child after one year. Over time, the number of persons perceiving gestational diabetes mellitus as a transient condition decreased. Respondents lacked information about the disease, diet and follow-ups.  

Beliefs changed over time and influenced health-related behaviour. Beliefs about the seriousness of gestational diabetes mellitus among health professionals'  influence development of patients' beliefs. Pregnancy should be used as an opportunity to provide complete information about the disease and future health risks. Continous information should be given after delivery and wishes for regular follow-ups should be met.