Cundy T et al. (2007) Differing causes of pregnancy loss in type 1 and type 2 diabetes. Diabetes Care 30: 2603–2607

Cundy et al. recently published data on the causes of pregnancy loss in women with type 1 or type 2 diabetes. Data were collected prospectively over a 20-year period at a diabetes pregnancy service in Auckland, New Zealand. The causes of pregnancy loss were assigned to one of five major categories (major congenital abnormalities, prematurity, chorioamnionitis, unexplained stillbirth, asphyxia during delivery) or to other causes.

There were 1,200 pregnancies in 903 women with diabetes. In 325 of these, diabetes was diagnosed during pregnancy and confirmed with a glucose tolerance test 6 weeks post-partum; 314 of the 325 women had type 2 diabetes. Mean HbA1c values were similar in women with known type 1 and type 2 diabetes. Women with type 2 diabetes had a significantly greater BMI and were more commonly of non-European descent than women with type 1 diabetes. A total of 42 pregnancy losses were recorded. More than 75% of pregnancy losses in women with type 1 diabetes were caused by congenital anomalies or prematurity. In women with type 2 diabetes, more than 75% of losses were caused by stillbirth, chorioamnionitis or birth asphyxia. Stillbirth was significantly more prevalent in women with type 2 diabetes than in those with type 1 diabetes.

The authors conclude that, although the rate of pregnancy loss was similar between women with type 1 and type 2 diabetes, the causes differed. They suggest that additional risk factors such as obesity have a substantial impact.