RÉSUMÉ
BACKGROUND: The aim was to study the effect of country of birth, educational level and county of residence on overweight and obesity among pregnant women in Norway. METHODS: Observational study based on Medical Birth Registry Norway and Statistics Norway. The study population consisted of 219 555 deliveries in 2006-2014. Body mass index (BMI) was registered at the first antenatal care visit. Multivariate regression analysis was used to explore the study aims. RESULTS: Overweight (BMI 25-29.9) was recorded in 22.3% of the women, obesity (BMI ≥30) in 12.2%. Highest rates of overweight (30.8%) and obesity (13.5%) was recorded among women from the Middle East and North Africa or with no education (30.7% and 17.2%). The prevalence of overweight and obesity was 39.5% in sparsely populated counties and 26.4% for women living in Oslo. Adjusted for country of birth, education level, age, parity, smoking and marital status, the relative odds of overweight and obesity were 65% (95% CI 59-72%) higher in sparsely populated counties compared to Oslo. CONCLUSIONS: The prevalence of overweight (BMI ≥25) was 34.5%. The factors associated with overweight were living in rural districts in Norway, lower education and being born in countries in the Middle East or Africa.