Abstract

Objectives Women with type 2 and type 1 diabetes have differing risk factors for pregnancy loss. We compared the rates and causes of pregnancy loss in women with type 1 and type 2 diabetes.

Research Design and Methods We utilized prospectively collected data on all pregnancies in a 20-year period (1986-2005) from a single center with a high prevalence of type 2 diabetes. Pregnancy losses included terminations for medical reasons and deaths up to 1 month postpartum, but not spontaneous pregnancy losses <20 weeks' gestation.

Results There were 870 pregnancies in women with known diabetes (330 type 1; 540 type 2) and 325 in women with diabetes diagnosed in pregnancy but persisting post-partum (97% type 2 diabetes). The rate of pregnancy loss was similar in type 1 and type 2 diabetes (2.6 vs 3.7%, p=0.39), but the causes of pregnancy loss differed. In type 1 diabetes >75% were attributable to major congenital anomalies or prematurely; in type 2 diabetes >75% were attributable to stillbirth or chorioamnionitis (p= 0.017). Women with type 2 and type 1 diabetes had similar HbA1c at presentation and near term, but the former were older (p<0.001), and more obese (p<0.0001).

Conclusions There are significant differences in the main causes of pregnancy loss in women with type 1 and type 2 diabetes. The higher rates of stillbirth in women with type 2 diabetes, suggest that other features, such as obesity, contribute significantly to pregnancy losses.