NCT07269015

CGM Accuracy in Pregnancy Study

Evaluation of the Accuracy of Continuous Glucose Monitoring Systems and Educational Needs in Pregnant Women With Diabetes: A Comparison Between Dexcom One Plus and FreeStyle Libre 2 Plus

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 66 (estimated)
• Sponsor: Hospital Mutua de Terrassa · Academic / Other
• Sex: Female
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

Pregnancy in women with diabetes remains a high-risk condition, requiring strict glycemic control due to rapid physiological changes that affect insulin sensitivity. Continuous glucose monitoring (CGM) provides detailed glucose trends, but the accuracy of newer, affordable systems such as Dexcom One Plus and FreeStyle Libre 2 Plus has not been evaluated during pregnancy. This prospective interventional study aims to compare the accuracy of these two CGM systems-both worn simultaneously-using capillary glucose as the reference. The study also evaluates educational needs, skills, attitudes, digital competence, lifestyle habits, and patient-reported outcomes among pregnant women with type 1 diabetes (T1D), type 2 diabetes (T2D), and gestational diabetes (GDM).

Detailed description

Women with diabetes during pregnancy experience increased risks of congenital malformations, neonatal morbidity, hypertensive disorders, and abnormal fetal growth. Continuous glucose monitoring (CGM) improves glycemic outcomes in type 1 diabetes (T1D) in pregnancy, yet evidence remains limited for type 2 diabetes (T2D) and gestational diabetes (GDM). Dexcom One Plus and FreeStyle Libre 2 Plus are recent low-cost systems with CE-mark approval for use in pregnancy, both with reported Mean Absolute Relative Difference (MARD) values around 8%. However, neither system has been specifically validated in pregnant populations. Physiological changes in pregnancy-including increased total body water and interstitial fluid-may alter CGM accuracy. Prior studies show that earlier FreeStyle Libre versions may overestimate hypoglycemia in pregnant women. Furthermore, women with T2D or GDM typically have little prior exposure to diabetes education or CGM technology, which may contribute to suboptimal glycemic control. This study evaluates the accuracy and usability of Dexcom One Plus and FreeStyle Libre 2 Plus during pregnancy, while also assessing educational and digital literacy needs to optimize CGM implementation in real-world clinical practice.

Conditions

• Pregestational Diabetes
• Continuous Glucose Monitoring

Interventions

Type	Name	Description
DEVICE	Dexcom One Plus	Worn on the upper arm for 10 days Two replacements during the 30-day study period Used with Dexcom mobile application
DEVICE	FreeStyle Libre 2 Plus	Worn on the opposite arm for 15 days One replacement during the 30-day study period Used as real-time CGM via LibreLink
PROCEDURE	Additional Study Procedures	Capillary glucose monitoring before meals, 1 hour postprandially, and during symptoms of hypoglycemia (Contour Instant) One baseline structured education session for participants without prior CGM experience Routine diabetes education according to national guidelines

Timeline

• Start date: 2025-12-01
• Primary completion: 2026-12-01
• Completion: 2027-01-01
• First posted: 2025-12-08
• Last updated: 2025-12-08

Locations

1 site across 1 country: Spain