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CGM Improves Outcomes for Pregnant Women and Their Babies

By Emma Ryan and Adam Brown

New CONCEPTT trial results show improved newborn health and more time-in-range in women with type 1 diabetes using CGM during pregnancy

At the recent European Association for the Study of Diabetes (EASD) conference, we saw exciting new results from the JDRF-funded CONCEPTT trial. The international study examined continuous glucose monitor (CGM) use in pregnant women with type 1 diabetes, where the goal was to keep blood sugar in the very tight range of 63-140 mg/dl. Compared to using a blood glucose meter (BGM) alone, use of CGM during pregnancy significantly benefitted both mothers and their newborn babies.

Most notably, newborn babies in women who used CGM during pregnancy were healthier: they were less likely to be admitted to the neonatal intensive care unit for longer than a day, had less dangerous newborn hypoglycemia, and stayed an average of 1 day less in the hospital. The data suggest that one of those costly negative outcomes could be prevented for every 6-8 mothers treated with CGM. Babies born to CGM mothers were also less likely to be born overweight.

For the moms wearing CGM, the device helped them spend an extra 100 minutes per day in a tight glucose target range (63-140 mg/dl), with 72 fewer minutes per day at glucose levels over 140 mg/dl. (High blood sugar is unhealthy for the baby, which is where CGM provided a lot of benefit in this study – allowing moms to catching highs quickly and correct them.) Notably, the benefit on A1c was fairly small: CGM users saw a 0.2% greater decline in A1c than BGM-alone users, though both groups started with an A1c under 7%.

The women in the study used the older Medtronic Guardian real-time CGM, which is less accurate and more painful to insert than more recent sensors like Abbott’s FreeStyle Libre, Dexcom’s G5, and Medtronic’s Guardian Sensor 3. As a result, CGM wear time was lower than in more recent studies. In addition, about 80% of the study participants reported frustrations with the older Medtronic Guardian device. Since the trial took three years to run, a year to plan, and spanned six countries (Canada, UK, Spain, Italy, Ireland, and the US), getting the latest CGM devices in was a challenge. With more recent devices, outcomes may have looked even better.

Infants born to women with type 1 diabetes continue to have less than optimal health outcomes, including preterm births, very high birth weights and complicated deliveries, and higher risk of birth defects. CONCEPTT breaks ground as the first trial to demonstrate CGM’s benefits on non-blood-sugar related health outcomes in pregnant women. As the investigators concluded, we hope this data spurs improvements on current standards of care by promoting “CGM [to] be offered to all pregnant women with type 1 diabetes using intensive insulin therapy.”

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