Glycemic control and selected pregnancy outcomes in type 1 diabetes women on continuous subcutaneous insulin infusion and multiple daily injections: the significance of pregnancy planning.

BACKGROUND: Two regimens are used to achieve excellent glycemic control during pregnancy in type 1 diabetes mellitus (T1DM): continuous subcutaneous insulin infusion (CSII) and multiple daily injections (MDI). We assessed their efficacy and safety and the effect of pregnancy planning.

METHODS: We examined 269 pregnant T1DM women: 157 treated with MDI (MDI group), 42 with CSII (CSII group), and 70 who switched from MDI to CSII in the first trimester (MDI/CSII group). There were 116 women who planned pregnancy: 58 in the MDI group, 38 in the CSII group, and 20 in the MDI/CSII group. The estimated differences in glycemic control and maternal and fetal outcomes were adjusted for baseline characteristics.

RESULTS: Mean glycated A1c (HbA1c) in the first trimester in the whole group was 6.9%, and the women differed depending on whether they planned pregnancy or not (P < 0.0001). A multiple regression model showed an average difference of about 0.9% in favor of pregnancy planning, with no interaction between the planning and treatments. In the second trimester, HbA1c decreased to a mean value of 5.8%, with improvement of HbA1c across all treatments: by 1.5% in not-planning and 0.9% in planning women. Despite greater improvement, not-planning women still had a higher HbA1c (by 0.3%, P = 0.05). In the third trimester, there was no further significant changes; nevertheless, women who planned pregnancy still had a lower HbA1c (by 0.5%, P = 0.02). There were 14 malformations, stillbirths, and perinatal infant deaths in the not-planning versus five in the planning group (P = 0.07). Patients in the CSII group had a 2 kg greater weight gain compared to the MDI group (15.0 kg vs. 13.0 kg; P = 0.005).

CONCLUSIONS: In pregnancy with T1DM, both MDI and CSII can provide excellent glycemic control. Pregnancy planning has a beneficial effect on glycemic control, independent from the therapy model. CSII seems to predispose to a larger weight gain in mothers.