Glycemic control assessed by continuous glucose monitoring during pregnancy in women with type 1 diabetes and its association with preeclampsia and gestational hypertension, an observational Swedish cohort study

Introduction: Women with type 1 diabetes type have increased risk of preeclampsia but it is not fully understood if degree of glycemic control is associated with this risk. Aims of this study was to assess associations between glycemic control using CGM (continuous glucose monitoring) and risk of preeclampsia and gestational hypertension. Material: and methods 120 pregnant Swedish women with type 1 diabetes using CGM were included. Background factors and pregnancy outcomes were collected from medical records. CGM data were collected via the internet based Diasend. Mean glucose, standard deviation (SD), percentage of time within (TIT), below (TBT), and above (TAT) target was presented in each trimester in women with and without preeclampsia. Associations between CGM and preeclampsia and gestational hypertension were analyzed with logistic regression and adjusted for confounders. Results: 20 women (16.6%) developed preeclampsia. There were no significant differences in maternal characteristics between women with or without preeclampsia except for smoking. Glycemic control improved with each trimester but was not optimal in either group. When analyzing associations between glucose variables and preeclampsia, no significant associations were found after adjustment for confounders. In nulliparous women there was a trend, however not significant, of higher mean glucose, higher SD, less TIT, more TAT and less TBT, in those who developed preeclampsia. We found no significant associations between glycemic control and development of gestational hypertension. Conclusions: Degree of glycemic control assessed by CGM was not associated with development of preeclampsia or gestational hypertension in women with type 1 diabetes in this study.