Longitudinal Observation of Insulin Requirements and Sensor Use in Pregnancy

Study Overview
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Brief Summary
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The overall goal of this study is to enroll pregnant women with type 1 diabetes and follow their glycemic outcomes prospectively throughout pregnancy and into the post-partum period. The investigators anticipate that when compared to subjects using an Artificial pancreas system (AP) as part of a future protocol, this comparator group of subjects undergoing usual care will exhibit less time in target continuous glucose monitoring (CGM) glucose range defined as 63-140 mg/dL and an increased duration of hypoglycemia with CGM glucose <63 mg/dL.

Detailed Description
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This is an observational study. Data collected will include records of continuous glucose monitoring (CGM) based glucose, insulin delivery, self-monitoring of blood glucose (SMBG), and maternal and fetal outcomes from pregnant women with type 1 diabetes. These data will be used to: (1) develop and refine algorithms for an AP system tailored to the needs of pregnant women with type 1 diabetes, (2) to serve as a comparator group for concurrent AP protocols, (3) describe Dexcom G6 CGM data throughout the pregnancy, and (4) describe insulin changes which occur in pregnancy.

Official Title
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Observational Study of Patient Important Outcomes in Pregnant Patients With Type 1 Diabetes Mellitus on Insulin Pump

Conditions
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Type 1 Diabetes Mellitus, Pregnancy in Diabetics

Intervention / Treatment
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* Device: Dexcom G6 CGM


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinical diagnosis, based on investigator assessment, of T1D for at least one year and using insulin for at least 1 year. Criteria for documented hyperglycemia (at least 1 must be met): Fasting glucose ≥126 mg/dL Two-hour OGTT glucose ≥200 mg/dL HbA1c ≥6.5% documented Random glucose ≥200 mg/dL with symptoms No data at diagnosis is available but the participant has a convincing history of hyperglycemia consistent with T1D Criteria for requiring insulin at diagnosis (1 must be met): Participant required insulin at diagnosis and continually thereafter. Participant did not start insulin at diagnosis but upon investigator review likely needed insulin (significant hyperglycemia that did not respond to oral agents) and did require insulin eventually and used continually. Participant did not start insulin at diagnosis but continued to be hyperglycemic, had positive islet cell antibodies - consistent with latent autoimmune diabetes in adults (LADA) and did require insulin eventually and used continually. Currently using an insulin pump for diabetes management Currently using or willing to use an insulin-to-carbohydrate ratio to calculate meal bolus sizes Willing to change insulin infusion site at least every 3 days. Confirmed pregnancy Current gestational age <17 weeks Age 18-40 years HbA1c <10.0% Demonstration of proper mental status and cognition for the study Ability to access the internet and upload CGM data remotely if needed An understanding of and willingness to follow the protocol and sign the informed consent Exclusion Criteria: 670 G users in Auto mode Current gestational age ≥17 weeks Cystic fibrosis A known medical condition that in the judgment of the investigator might interfere with the completion of the protocol such as the following examples: Inpatient psychiatric treatment in the past 6 months Abnormal renal function test results (calculated GFR <60 mL/min/1.73m2); testing required for subjects with diabetes duration of greater than 5 years post onset of puberty Active gastroparesis Abuse of alcohol or recreational drugs Infectious process not anticipated to resolve prior to study procedures (e.g. meningitis, pneumonia, osteomyelitis) Uncontrolled arterial hypertension (Resting diastolic blood pressure >95mmHg and/or systolic blood pressure >160 mmHg) at the time of screening Chronic oral steroid use A recent injury to body or limb, muscular disorder, use of any medication, any carcinogenic disease, or other significant medical disorder if that injury, medication or disease in the judgment of the investigator will affect the completion of the protocol

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| type 1 diabetes and pregnancy<br>Pregnant women with T1D on insulin pumps (CSII/SAP/PLGS) will be offered enrollment in a prospective study that will capture: 1) Dexcom G6 CGM data, 2) self-monitoring of blood glucose (SMBG), 3) insulin pump settings, 4) insulin delivery records, and 5) maternal and fetal outcomes. | Device: Dexcom G6 CGM<br>* All women in the study will be given Dexcom G6 CGM and a study glucometer.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time in range glucose levels as determined by CGM | Time in range defined as 63-140 mg/dL as determined by CGM analysis | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time spent below target glucose range | Time spent below target cgm glucose range defined as glucose <63 mg/dL | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 
| Frequency of severe hypoglycemic events | Frequency of severe hypoglycemic events, defined as requiring assistance from another, an emergency room visit or treatment with glucagon due to unconsciousness | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 
| Time spent above target glucose range | Time spent above target cgm glucose range defined as >140 mg/dL | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 
| Episodes of clinically significant hyperglycemia | Episodes of clinically significant hyperglycemia with CGM glucose >180 mg/dL | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 
| Extent of glucose variability (GV) | Glucose variability, defined using predetermined metrics of GV | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 
| Percent of time CGM active | Percent of time CGM active per day (minutes of use/24 hours) | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 
| Concordance of CGM data in relation to SMBG data | Comparison of concordance of CGM data with measured SMBG glucose levels | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 
| Total daily insulin requirements | Change in total daily insulin during pregnancy and the postpartum period (units/day) | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 
| Basal insulin requirements | Change in basal insulin during pregnancy and the postpartum period (units/day) | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 
| Insulin-to-carbohydrate ratio changes | Change in insulin-to-carbohydrate ratio during pregnancy and the postpartum period (units/day) | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 
| Insulin sensitivity changes | Change in insulin sensitivity during pregnancy and the postpartum period | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 
| Carbohydrate consumption | Change in carbohydrate consumption during pregnancy and the postpartum period (grams/day) | Prior to 17 weeks gestation (enrollment) through up to 6 weeks postpartum | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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type 1 diabetes, pregnancy, continues glucose monitoring, artificial pancreas