Aim: To compare the outcomes of Type 1 and Type 2 diabetic pregnancies and identify risk factors for poor outcome of Type 2 pregnancies
Methods: The data from all (389 Type 1 and 146 Type 2) pre-gestational diabetic pregnancies from 10 UK hospitals were collected prospectively.
Results: The Type 2 mothers were less likely to have documented pre-pregnancy counselling (28.7 vs. 40.5%; P<0.05) or be taking folic acid at conception (21.9 vs. 36.4%; P<0.001) than Type 1 mothers. The percentage of pregnancies having a serious adverse outcome was higher in Type 2 patients (16.4 vs. 6.4%; P=0.002). Congenital abnormalities (12.3% in Type 2 vs. 4.4% in Type 1; P=0.002) accounted for most of this difference. The HbA1c of the Type 2 patients was similar to that of the Type 1 with mean first trimester HbA1c of 7.22 and 7.35%, respectively (P=0.5). Treatment with oral hypoglycaemic agents [odds ratio (OR), 1.8; 95% confidence interval (CI), 1.0-3.3; P=0.04], body mass index (OR, 1.09; 95% CI, 1.01-1.18; P=0.02) and folic acid supplementation (OR, 0.3; 95% CI, 0.09-1.0; P=0.04) were all independently associated with congenital malformation.
Conclusion: Type 2 diabetic pregnancies are characterized by poor pre-pregnancy planning, inadequate folic acid supplementation and treatment with oral hypoglycaemic agents, all of which may contribute to the serious adverse outcomes affecting one in six Type 2 diabetic pregnancies. These remediable aspects of the pre-pregnancy care of women with Type 2 diabetes provide opportunities for improving the outcome towards that of women with Type 1 diabetes.