Peri-conceptional HbA1c and risk of serious adverse pregnancy outcome in 933 women with type 1 diabetes

doi:10.2337/dc08-2061

Peri-conceptional HbA1c and risk of serious adverse pregnancy outcome in 933 women with type 1 diabetes

Dorte M. Jensen, PhD (dortemj{at}dadlnet.dk)^a,
Lars Korsholm, PhD^a,
Per Ovesen, DMSc^c,
Henning Beck-Nielsen, DMSc^a,
Lars Moelsted-Pedersen, DMSc^d,
Jes G. Westergaard, DMSc^e,
Margrethe Moeller, MD^f and
Peter Damm, DMSc^g

^aDept. of Endocrinology, Odense University Hospital, University of Southern Denmark
^bInstitute of Statistics and Demographics University of Southern Denmark
^cDept. of Obstetrics and Gynecology, Aarhus University Hospital, Skejby
^dDept. of Obstetrics and Gynecology, Copenhagen County Hospital, University of Copenhagen
^eDept. of Obstetrics and Gynecology, Odense University Hospital
^f Dept. of Obstetrics and Gynecology, Aalborg University Hospital
^gCenter for Pregnant Women with Diabetes, Dept. of Obstetrics, Rigshospitalet, University of Copenhagen, Faculty of Health Sciences

Abstract

Objectives : To study the association between peri-conceptional HbA1c and serious adverse pregnancy outcome (congenital malformations and perinatal mortality).

Methods: Prospective data collection in 933 singleton pregnancies complicated by type 1 diabetes.

Results: The risk of serious adverse outcome at different HbA1c levels was compared to the background population. The risk was significantly higher when peri-conceptional HbA1c exceeded 6.9%, and the risk tended to increase gradually with increasing HbA1c, and women with HbA1c exceeding 10.4% had a very high risk of 16%. Congenital malformation rate increased significantly at HbA1c above 10.4% whereas perinatal mortality was increased even at Hba1c below 6.9%.

Conclusions: These results support recent guidelines of pre-conceptional HbA1c levels below 7% in women with type 1 diabetes.