Prepregnancy care and pregnancy outcomes in women with type 1 diabetes.

OBJECTIVE The objective of this study was to examine the relationship between prepregnancy care, glycemic control, maternal hypoglycemia, and pregnancy outcomes in women with type 1 diabetes. RESEARCH DESIGN AND METHODS This was a prospective observational cohort study of women with type 1 diabetes who delivered from 1991 to 2002. Outcome measures were attendance at a clinic for prepregnancy care, maternal HbA(1c) (A1C) throughout pregnancy, maternal severe hypoglycemic episodes, macrosomia, preeclampsia, premature delivery (delivery before 37 weeks), very premature delivery (delivery before 34 weeks), spontaneous abortion, and adverse pregnancy outcome (defined as major malformation, stillbirth, and neonatal death). RESULTS There were 290 pregnancies, in which 110 (38%) women had prepregnancy care. The prepregnancy care group contained more primiparous women (54.7 vs. 40.6%; P = 0.021) and fewer smokers (9.4 vs. 28.7%; P < 0.0001). They registered earlier (6.6 vs. 8.3 weeks, P < 0.0001) and had a lower A1C at the initial visit (6.5% vs. 7.6%; P < 0.0001). Adverse pregnancy outcomes and very premature deliveries were significantly lower in women who received prepregnancy care (2.9 vs. 10.2%; P = 0.03 and 5.0 vs. 14.2%; P = 0.02, respectively). In contrast, between groups, there was no difference in A1C after 24 weeks or in the rates of macrosomia, preeclampsia, or maternal severe hypoglycemic episodes. CONCLUSIONS Prepregnancy care was associated with improved glycemic control in early pregnancy and significant reductions in adverse pregnancy outcome (malformation, stillbirth, and neonatal death) and very premature delivery. However, prepregnancy care failed to have an impact on glycemic control in later pregnancy or to reduce the risk of macrosomia and preeclampsia.