COntinuous Glucose Monitoring in nEwborns of Mothers With Insulin-Treated Gestational Diabetes Mellitus (COMET-GDM)

COntinuous Glucose Monitoring in nEwborns of Mothers With Insulin-Treated Gestational Diabetes Mellitus (COMET-GDM): a Randomised Controlled Trial

The purpose of this study is to determine whether continuous glucose monitoring (CGM) improves the detection and management of neonatal hypoglycaemia in newborns of mothers with insulin-treated gestational diabetes.

Study Overview

• Status: Not yet recruiting
• Conditions: Neonatal Hypoglycemia; Gestational Diabetes Mellitus (GDM)
• Intervention / Treatment: Device: Dexcom ONE Continuous Glucose Monitoring System

Detailed Description

Gestational diabetes mellitus (GDM) is a form of glucose intolerance affecting up to 14% of pregnant women and is associated with an increased risk of multiple maternal and fetal complications. This risk is proportional to the degree of maternal hyperglycaemia. Appropriate glycaemic control and dietary management are key components of GDM treatment. However, in approximately 10-30% of cases, pharmacological therapy is required, due to persistent fasting hyperglycaemia.

Neonatal hypoglycaemia is one of the most common metabolic complications associated with GDM, affecting approximately 5-15% of newborns, and is linked to increased morbidity. There is currently no universal consensus regarding the lowest safe blood glucose threshold required to prevent neurological complications in this population. Nevertheless, persistent or recurrent hypoglycaemia, that is unresponsive to treatment is known to be associated with adverse neurological outcomes.

Following birth and umbilical cord clamping, the newborn must maintain glucose homeostasis through endogenous production via glycogenolysis and gluconeogenesis, as well as through enteral feeding. This physiological transition results in lower blood glucose concentrations during the first 4 hours of life and increases the risk of neonatal hypoglycaemia. Furthermore, in pregnancies complicated by insulin-treated GDM, chronic maternal hyperglycaemia leads to hypertrophy of the fetal pancreatic islets and fetal hyperinsulinaemia, which further increases the risk of hypoglycaemia after birth.

Current clinical guidelines rely on intermittent capillary blood glucose measurements performed at predetermined intervals. However, this scheduled testing approach may fail to detect transient hypoglycaemic episodes.

Continuous glucose monitoring (CGM) enables continuous measurement of interstitial glucose concentrations. Despite its potential advantages, there is limited evidence regarding the clinical significance of CGM use in neonates born to mothers with insulin-treated gestational diabetes.

The aim of this study is to determine whether CGM improves the detection and management of neonatal hypoglycaemia in newborns of mothers with insulin-treated gestational diabetes. This study is designed as a single-centre, randomised controlled trial conducted at the Department of Neonatology and Neonatal Intensive Care, Institute of Mother and Child, Warsaw, Poland.

In the intervention group (CGM group), glucose concentrations will be monitored using CGM. Routine scheduled capillary blood glucose measurements will not be performed unless clinically indicated.

In the control group (standard monitoring group), glucose concentrations will be measured using capillary blood glucose testing in accordance with the local standard protocol. A CGM sensor will also be applied; however, glucose recordings will be masked to both clinical staff and parents.

In both groups, CGM will continuously collect glucose data for the first 72 hours after birth.

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Poland
  • Warsaw, Poland, 01-211
    • Institute of Mother and Child
    • Contact: Aleksandra H Symonides-Pomianek; Phone Number: +48 22 32 77 406; Email: aleksandra.symonides@imid.med.pl
    • Contact: Paweł Krajewski, MD, PhD, Assoc. Prof.; Phone Number: +48 22 32 77 406; Email: pawel.krajewski@imid.med.pl
    • Principal Investigator: Aleksandra H Symonides-Pomianek, MD
    • Sub-Investigator: Agata Majewska, MD, PhD
    • Sub-Investigator: Maciej Rączka, MD
    • Sub-Investigator: Paweł Krajewski, MD, PhD, Assoc. Prof.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Maternal age of 18 years or older
• Singleton pregnancy
• Insulin-treated gestational diabetes mellitus

Exclusion Criteria:

• Multifetal pregnancy
• Congenital malformations or metabolic defects in the newborn
• Preterm birth (defined as birth <37 weeks of gestation)
• Smoking during pregnancy
• Preeclampsia, fetal growth restriction
• Perinatal asphyxia
• Congenital infections in the newborn
• Adverse skin reactions (eczema, wounds) in the planned sensor insertion area

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Continuous glucose monitoring; Neonates undergo continuous glucose monitoring (CGM), with real-time glucose values visible to the clinical team. CGM data may be used to support the detection and clinical management of neonatal hypoglycaemia in accordance with the study protocol.	Device: Dexcom ONE Continuous Glucose Monitoring System; The Dexcom ONE continuous glucose monitoring system is applied to all participants. Following randomisation, CGM data are either available in real time to the clinical team (intervention group) or recorded in masked mode and not available to the clinical team, and therefore do not influence clinical management (control group).
Active Comparator: Blood glucose testing based on standard care procedures; Detection and management of neonatal hypoglycaemia are based on standard care procedures, as defined by the local protocol. Additionally, neonates undergo continuous glucose monitoring (CGM) in masked mode. CGM values are not visible to the clinical team and do not guide clinical decision-making.	Device: Dexcom ONE Continuous Glucose Monitoring System; The Dexcom ONE continuous glucose monitoring system is applied to all participants. Following randomisation, CGM data are either available in real time to the clinical team (intervention group) or recorded in masked mode and not available to the clinical team, and therefore do not influence clinical management (control group).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Neonatal hypoglycaemia	Number of hypoglycaemic episodes per neonate, defined as the number of CGM-recorded glucose values <40mg/dl (2.2 mmol/L) occuring within the first 72 hours after birth.	From birth until 72 hours of life

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total cumulative duration of hypoglycaemia per neonate within the first 72 hours of life	Total cumulative duration of hypoglycaemia per neonate within the first 72 hours of life, defined as the sum of all time periods during which CGM-measured glucose concentration is <40 mg/dL (2.2 mmol/L), expressed in minutes.	From birth until 72 hours of life
Number of hypoglycaemia-related clinical interventions per neonate during the monitoring period	Number of clinical interventions (feeding, oral glucose, intravenous glucose administration) per neonate during the monitoring period due to hypoglycaemia	From birth until 72 hours of life
Number of capillary blood glucose measurements per neonate	Number of capillary blood glucose measurements per neonate during the monitoring period in the control group.	From birth until 72 hours of life
Measures of glucose variability per neonate within the first 72 hours of life	Glucose variability metrics derived from CGM data, including: standard deviation (SD) of glucose concentration, and; coefficient of variation (CV), calculated as SD divided by mean glucose and expressed as a percentage.	First 72 hours after birth
Percentage of time with glucose <40 mg/dL	Percentage of time with glucose <40 mg/dL (2.2 mmol/L) per neonate within the first 72 hours after birth	From birth until 72 hours of life
Proportion of neonates by feeding type at hospital discharge	Proportion of neonates receiving exclusive breastfeeding, mixed feeding (breast milk and formula), or exclusive formula feeding at the time of hospital discharge.	At the time of hospital discharge

Collaborators and Investigators

• Sponsor: Institute of Mother and Child, Warsaw, Poland

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: February 27, 2026
• First Submitted That Met QC Criteria: March 8, 2026
• First Posted (Actual): March 10, 2026

Study Record Updates

• Last Update Posted (Actual): March 10, 2026
• Last Update Submitted That Met QC Criteria: March 8, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: gestational diabetes mellitus; neurodevelopmental outcomes; neonatal hypoglycemia; insulin-treated gestational diabetes
• Additional Relevant MeSH Terms: Urogenital Diseases; Endocrine System Diseases; Female Urogenital Diseases and Pregnancy Complications; Metabolic Diseases; Pregnancy Complications; Glucose Metabolism Disorders; Diabetes Mellitus; Nutritional and Metabolic Diseases; Diabetes, Gestational
• Other Study ID Numbers: 42/2025 (Other Identifier: Bioethics Committee at Institute of Mother and Child, Warsaw, Poland)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No