First-trimester continuous glucose monitoring parameters in preeclamptic and normotensive patients with type 1 diabetes.

OBJECTIVE

Preeclampsia disproportionately affects women with pregestational type 1 diabetes (T1D). This study aims to determine whether continuous glucose monitoring (CGM)-derived metrics during the first trimester predict the development of preeclampsia in pregnancies complicated by pregestational T1D, comparing their predictive capability against standard glycemic markers.

MATERIALS AND

METHODS

This single-center, retrospective cohort study analyzed data from 2019 to 2023 at a tertiary center in Poland. Participants included women with T1D on sensor-augmented insulin pump (SAP) therapy, initiating monitoring by 13 weeks/6 days. Sensor mean glucose, TIR, CV%, GMI and time spent over 140, 180 and 250 mg/dL were analyzed and preeclampsia diagnosis adhered to ISSHP criteria, with data compared.

RESULTS

Of 70 women, 13 (18.6 %) developed preeclampsia. Baseline HbA1c was similar. Sensor-derived glucose metrics revealed higher first-trimester mean glucose (121.6 mg/dL vs. 112.3 mg/dL, p = 0.0012), decreased TIR 63.3% (54.3-68.46) vs 70.16 % (67.31-76.57), p = 0.03, and coefficient of variation 38.42% vs 34.29, p = 0,055 for the PE group. Good glycemic control existed in both groups during later trimesters.

CONCLUSION

Elevated first-trimester mean glucose and glucose variability could be linked with preeclampsia in T1D, in our study. Findings support CGM to refine risk models and strategies addressing early glycemic imbalances in T1D pregnancies.