(683) Postpartum glucose tolerance test results among people with gestational diabetes using continuous glucose monitoring

This was a secondary analysis of pregnant people with GDM randomized to using CGM versus capillary blood glucose (CBG) for management of GDM. Our primary outcome was mean glucose during an OGTT comparing people who had abnormal postpartum OGTT (fasting ≥100 mg/dL or 2-hour ≥140 mg/dL) compared to normal OGTT results. We performed additional stratified analyses of those by GDM type.

Results:

Of the 111 participants in the initial trial, there were 51 that had postpartum data available for inclusion of this secondary analysis. Participants had higher fasting (104.3 ± 10.5 vs 89.8 ± 5.2) and 2-hour plasma glucose (129.9 ± 37.5 vs 103.5 ± 17.9) in the group with abnormal postpartum OGTT results compared to those with a normal OGTT response. Additionally, the glucose excursion following the 75 grams of glucose and mean CGM glucose at all time points were higher in the group with abnormal OGTT results (Figure). When stratified by GDM type, mean CGM glucose was similar between groups.

Conclusion: This study demonstrates that CGM values follow the expected trend regarding physiologic response to the OGTT, and those with abnormal OGTT results had a distinct glycemic pattern in response to the OGTT with higher mean CGM glucose at all time points assessed. Future studies will need to assess the predictability of CGM in identifying those with abnormal glycemia postpartum (i.e. prediabetes) with an elevated risk for development of type 2 diabetes mellitus.