Objectives: We examined the impact of continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring systems (CGM) during pregnancy in women with pre-gestational type 1 diabetes (T1DM) on glycemic control and subsequent adverse outcomes.
Material and methods: In this observational, one-center study we analyzed records of consecutive 109 T1DM pregnancies (2016-2017). The final analyzed group consisted of 81 singleton pregnancies who met inclusion and exclusion criteria. We searched for the association between the use of CSII with or without CGM and pregnancy planning with glycated hemoglobin A1c (HbA1c) through pregnancy and after delivery as well as maternal and infant outcomes.
Results: Patients using CSII and CGM vs CSII without CGM and MDI (multiple daily injections) users had the lowest HbA1c levels during and after pregnancy (5.3%, 5.3%, 5.2% and 5,5% in the 1st, 2nd, 3rd trimester and postpartum visit, p = 0.003, p = 0.030, p = 0.039 and p = 0.002, respectively). Patients treated with insulin pumps with CGM and additional functions of automatic insulin delivery suspension on low glucose level (SLG) or predictive low glucose suspend (PLGS) during the third trimester and after pregnancy achieved a significantly lower HbA1c than the other CSII patients. We did not find any differences between the study groups in gestational age at delivery, preterm births, birth weight or macrosomia risk. Despite very good glycemic control, the risk of macrosomia remained high (19.7%).
Conclusions: The use of pumps equipped with CGM, especially with automatic insulin delivery suspension, may improve glycemic control in pregnant T1DM women. The proportion of macrosomia remained high.
Keywords: continuous glucose monitoring; insulin pump; macrosomia; pregnancy; type 1 diabetes.