Gestational diabetes mellitus among foreign-born women in Sweden: A register-based study on the role of income.

Sammanfattning: Aim:  The present study aimed to determine if foreign-born women from different countries of birth have a greater risk of GDM compared to Swedish-born women and to what extent income might mediate this relationship. Methods: This cross-sectional type study included 835279 women, of which 151,642 were foreign-born and 683637 were Swedish-born women who gave birth to their first singleton child in Sweden between 1997 to 2016. Register data from the Swedish Medical Birth Register, the Swedish Total Population Register, and the Longitudinal Integrated Database for Health Insurance and Labour Market Studies was used. Multiple Logistic Regression analysis and the Karlson-Holm-Breen methods were used to explore the relationship between GDM and country of birth and to estimate the proportion of the association explained by income. Results:  Foreign-born women demonstrated higher odds ratios for developing GDM than Swedish-born women. South East Asian women showed the highest risk of GDM (OR: 4.40, CI: 4.01-4.81) followed by Africa (OR: 3.42, CI: 3.07-3.81) and Middle East & North Africa (OR: 2.92, CI: 2.67-3.20) respectively. Income partially explained the risk of GDM differences between foreign-born and Swedish-born women, accounting for 26% of the association. However, the proportion explained by income varies from 8.9% to 23.0% by country of birth. Conclusions:  A disparity exists in the risk of GDM based on country of birth, and Foreign-born women are more likely to have GDM and need additional support, including prenatal care and treatment. Since income only partially explains this association, other factors that may explain the association need to be explored.