Abstract
Objective. To estimate the risk of congenital anomalies in offspring of women with type 1 diabetes in Norway during recent years. Design. Nationwide population-based study using the Medical Birth Registry of Norway and the Norwegian type 1 Diabetes Registry. Setting. All birth clinics in Norway. Participants. All births in Norway during 1999–2004 (N = 350,961), of which 1,583 were births by a mother registered with pregestational type 1 diabetes. Main outcome measure. Congenital anomalies, excluding minor anomalies according to the EUROCAT system. Results. Anomalies were registered in 5.7% of offspring of women with type 1 diabetes, and in 2.9% among the background population (odds ratio 2.1, 95% CI: 1.7–2.6). Cardiovascular anomalies were registered in 3.2% in the diabetes group and 0.94% in the background population (odds ratio 3.5, 95% CI: 2.7–4.7). Results were similar when restricted to women identified with type 1 diabetes through the Diabetes Registry. Conclusions. Women in Norway with type 1 diabetes experience a significantly higher risk of congenital anomalies in their babies compared with the background population.
Acknowledgements
This study was supported by a grant from the South-Eastern Norway Regional Health Authority, and initiation of the study was supported by a post-doc grant to L.C. Stene from the Norwegian Research Council. We thank Lorentz Irgens and the staff at the Medical Birth Registry of Norway for linking registries, Kari Klungsøyr Melve at the registry for valuable information, and Rolv Skjærven and Anne Kjersti Daltveit for comments on the manuscript.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.