Glucose Testing in GDM: Adherence to One- Versus Two-hour Postprandial Glucose Monitoring in Gestational Diabetics

Study Overview
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Brief Summary
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The purpose of this study is to evaluate if in patients with gestational diabetes (GDM), adherence to postprandial glucose monitoring differs when performed 1-hour versus 2-hours after eating. The primary objective of this study is to evaluate difference in rate of adherence (binary outcome defined as <80% or ≥80% of glucose log completed) between gestational diabetics who perform 1-hour versus 2-hour postprandial blood glucose testing.

Detailed Description
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Consented patients who are diagnosed with gestational diabetes will be randomized to either 1-hour or 2-hour postprandial blood glucose monitoring. A retrospective chart review from July 2020 until study commencement for patients from the same clinic will be used as a historical control group. This study will assess differences in adherence to testing.

Official Title
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Adherence to One- Versus Two-hour Postprandial Glucose Monitoring in Gestational Diabetics: A Randomized Trial

Conditions
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Gestational Diabetes

Intervention / Treatment
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* Other: 1 hour Blood glucose monitoring
* Other: 2 hour blood glucose monitoring


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pregnant patients with singleton gestation who are ≥ 18 years of age. Diagnosis of GDM after 24 0/7 weeks. For diagnosing GDM, a two-step screening algorithm will be performed according to the American College of Obstetrics and Gynecologists.4 Specifically, a 1-hour 50-g glucose-loading test is given first. Plasma glucose levels between 140 and 200 mg/dL will be considered elevated. Confirmatory testing will then be performed using a 3-hour 100-g glucose tolerance test. Diagnosis was made when two of the four values were elevated. Abnormal glucose value thresholds are established via the criteria suggested by Carpenter and Coustan: fasting value ≥ 95 mg/dL, 1-hour ≥ 180 mg/dL, 2-hour ≥ 155 mg/dL, and 3-hour ≥ 140 mg/dL.9 Patients with a blood glucose level greater than 200 mg/dL after 1-hour 50-g glucose-loading test will be diagnosed with GDM without requirement for the 3-hour 100-g glucose tolerance test. Exclusion Criteria: Type 1 pre-gestational diabetes Type 2 pre-gestational diabetes GDM diagnosed prior to 24 0/7 weeks gestation.

Ages Eligible for Study
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Minimum Age: 18 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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Design Details

Primary Purpose: Health Services Research
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: 1-hour post-prandial blood glucose monitoring Arm<br>Arm in which participants are randomized to blood glucose monitoring at 1 hour after eating. | Other: 1 hour Blood glucose monitoring<br>* Consented patients who are diagnosed with gestational diabetes will be randomized to 1-hour postprandial blood glucose monitoring.<br>|
| Other: 2-hour post-prandial blood glucose monitoring Arm<br>Arm in which participants are randomized to blood glucose monitoring at 2 hours after eating. | Other: 2 hour blood glucose monitoring<br>* Consented patients who are diagnosed with gestational diabetes will be randomized to 2 hour post prandial blood glucose monitoring<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of adherence | Evaluate rate of adherence (binary outcome defined as <80% or ≥80% of glucose log completed) between gestational diabetics who perform 1-hour versus 2-hour postprandial blood glucose testing. | During the intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of postprandial glucose log complete, averaged over the duration of the study period |  | During the intervention | 
| Percentage of postprandial glucose log complete for each meal (breakfast, lunch, and dinner), averaged over the duration of the study period |  | During the intervention | 
| Percentage of elevated blood glucose values per week, averaged over the duration of the study period |  | During the intervention | 
| Number of patients who start insulin or oral hyperglycemic medication therapy prior to delivery. |  | During the intervention | 
| Gestational age at medication therapy initiation |  | During the intervention | 
| Timeframe from diagnosis of gestational diabetes to initiation of insulin therapy |  | During the intervention | 
| Number of subjects with a vaginal delivery |  | At time of delivery | 
| Number of subjects with an operative delivery |  | At time of delivery | 
| Number of subjects with a caesarean section delivery |  | At time of delivery | 
| Number of subjects with a preeclampsia diagnosis |  | During intervention | 
| Neonatal birthweight |  | At time of delivery | 
| Number of subjects with shoulder dystocia |  | At time of delivery | 
| Number of patients with 3rd or 4th degree perineal lacerations |  | At time of delivery | 
| Number of patients with postpartum hemorrhage. |  | At time of delivery | 
| Number of stillbirths |  | At time of delivery | 
| Number of NICU admissions |  | At time of delivery | 
| Number of patients requiring supplemental oxygen support |  | At time of delivery | 
| Number of patients with diagnosis of hypoglycemia |  | At time of delivery | 
| Number of patients with diagnosis of hyperbilirubinemia |  | At time of delivery | 
| Number of patients with clavicular fracture |  | At time of delivery | 
| Number of patients with humeral fracture |  | At time of delivery | 
| Number of patients with brachial plexus palsy |  | At time of delivery |