Diabetes, Gestational
Conditions
Brief summary
Diabetic pregnant patients are at risk for adverse pregnancy outcomes, including larger than expected fetuses and unplanned operative deliveries, due to elevated blood glucose levels. the one-hour glucola test is currently used to screen pregnant patients for gestational diabetes. This involves ingesting a 50-gram glucose load, followed by a blood test one hour later. We wish to compare 7-day continuous glucose monitoring to the one-hour glucola test, and determine which one correlates better with adverse pregnancy outcomes as well as which one more accurately identifies patients at risk for adverse pregnancy outcomes.
Detailed description
All pregnant patients without pre-existing diabetes will be eligible for the study. Interest in participation will be determined at their initial prenatal visit. Those that are interested will be consented. Between 24-28 weeks of gestation, the recommended period of glucola testing, a soft sensor for continuous glucose monitoring system (CGMS) will be inserted superficially under the skin. The patient will be instructed on how to wear and care for the device. She will wear the CGMS for 7 days, then return to the clinic for removal of the device, and downloading of the data. She will perform the routine glucola test sometime between days 2 to 7 . Finger stick blood glucoses will be checked by the patient 2 times daily during the 7 days of wearing the CGMS. Results of CGMS will not be available to the patient or her physician until after completion of the pregnancy. The patient will be treated routinely, based on the results of the routine glucola test.
Interventions
DEVICEThe Seven Continuous Glucose Monitoring System
Between 24-28 weeks of gestation, the recommended period of glucola testing, a soft sensor for continuous glucose monitoring system (CGMS) will be inserted superficially under the skin. The patient will be instructed on how to wear and care for the device. She will wear the CGMS for 7 days, then return to the clinic for removal of the device, and downloading of the data. Finger stick blood glucoses will be checked by the patient 2 times daily during the 7 days of wearing the CGMS.
Sponsors
DexCom, Inc.
Stanford University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 50 Years
Healthy volunteers
No
Inclusion criteria
* Pregnant patients * Age 18-50 * Gestational age less than 28 weeks
Exclusion criteria
* Minors less than 18 years of age * Multiple gestation * Known fetal anomalies
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Correlation Between Glucose AUC and Birth Weight. | CGM measured 7 days at beginning of pregnancy,birth weight measured a time of delivery | For each patient's CGM data, we calculated the total area under the curve (AUC) for values above the predefined cutoffs of 110, 120, 130, 140, and 180 mg/dL. Patients wore the CGM for different amounts of time; therefore, the total AUC for the entire duration of CGM use was divided by the number of 24-hour periods of data collection. We called these normalized values AUC-110, AUC-120, AUC-130, AUC-140, and AUC-180, and they reflect both the magnitude and duration of hyperglycemic excursions above the predetermined thresholds in an average 24-hour period. Birth weight percentile was determined using birth weight data derived from 1999 and 2000 United States Natality datasets. The correlation coefficient (r) was calculated between birth weight percentiles and each of the following: AUC-110, AUC-120, AUC-130, AUC-140, AUC-180, and 1-hour GCT result. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Pregnancy and Delivery Characteristics for Participants With AUC-130 <= 22,000 and AUC-130 > 22,000 | CGM measured 7 days at beginning of pregnancy,birth weight measured a time of delivery | For our secondary outcome analyses,we chose to focus on AUC-130 because 130 mg/dL is a common threshold used when treating gestational diabetics. In addition, 130 mg/dL was the threshold used in an earlier pilot study performed at our institution because it had the best correlation with birth weight percentile. Secondary outcomes were compared between these two groups using the chi-square test. Data were analyzed using Stata 11.2. AUC-130 values were divided into high and low at a cutoff of 22,000, which was the 90th percentile of AUC-130 values. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Continuous Glucose Monitor for Diabetes in Pregnancy Screening The Seven Continuous Glucose Monitoring System: Between 24-28 weeks of gestation, the recommended period of glucola testing, a soft sensor for continuous glucose monitoring system (CGMS) will be inserted superficially under the skin. The patient will be instructed on how to wear and care for the device. She will wear the CGMS for 7 days, then return to the clinic for removal of the device, and downloading of the data. Finger stick blood glucoses will be checked by the patient 2 times daily during the 7 days of wearing the CGMS. | 53 |
| Total | 53 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Physician Decision | 1 |
Baseline characteristics
| Characteristic | Continuous Glucose Monitor for Diabetes in Pregnancy Screening |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 53 Participants |
| Age, Continuous | 30 years STANDARD_DEVIATION 5 |
| BMI at enrollment | 32.5 kg/m2 STANDARD_DEVIATION 8.5 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 24 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 29 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Gestational Age at Enrollment | 25.9 weeks STANDARD_DEVIATION 1.2 |
| Insurance status Private | 24 participants |
| Insurance status Public | 29 participants |
| Parity Multiparous | 30 participants |
| Parity Nulliparous | 23 participants |
| Pre-pregnancy BMI | 29.1 kg/m2 STANDARD_DEVIATION 8.4 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 11 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 2 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 2 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 24 Participants |
| Race (NIH/OMB) White | 14 Participants |
| Region of Enrollment United States | 53 participants |
| Sex: Female, Male Female | 53 Participants |
| Sex: Female, Male Male | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 57 |
| serious Total, serious adverse events | 0 / 57 |
Outcome results
Primary
Correlation Between Glucose AUC and Birth Weight.
For each patient's CGM data, we calculated the total area under the curve (AUC) for values above the predefined cutoffs of 110, 120, 130, 140, and 180 mg/dL. Patients wore the CGM for different amounts of time; therefore, the total AUC for the entire duration of CGM use was divided by the number of 24-hour periods of data collection. We called these normalized values AUC-110, AUC-120, AUC-130, AUC-140, and AUC-180, and they reflect both the magnitude and duration of hyperglycemic excursions above the predetermined thresholds in an average 24-hour period. Birth weight percentile was determined using birth weight data derived from 1999 and 2000 United States Natality datasets. The correlation coefficient (r) was calculated between birth weight percentiles and each of the following: AUC-110, AUC-120, AUC-130, AUC-140, AUC-180, and 1-hour GCT result.
Time frame: CGM measured 7 days at beginning of pregnancy,birth weight measured a time of delivery
Population: A total of 57 patients were enrolled from two clinical sites. Two patients did not have monitoring or delivery data.~Two patients who had an existing diagnosis of diabetes were excluded. The remaining 53 patients were analyzed.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Continuous Glucose Monitor for Diabetes in Pregnancy Screening | Correlation Between Glucose AUC and Birth Weight. | AUC-130 to birth weight centile | 0.2915 correlation coefficient |
| Continuous Glucose Monitor for Diabetes in Pregnancy Screening | Correlation Between Glucose AUC and Birth Weight. | AUC-140 to birth weight centile | 0.2859 correlation coefficient |
| Continuous Glucose Monitor for Diabetes in Pregnancy Screening | Correlation Between Glucose AUC and Birth Weight. | AUC-180 to birth weight centile | 0.2499 correlation coefficient |
| Continuous Glucose Monitor for Diabetes in Pregnancy Screening | Correlation Between Glucose AUC and Birth Weight. | 1hr GCT to birth weight centile (n=44) | -0.0234 correlation coefficient |
| Continuous Glucose Monitor for Diabetes in Pregnancy Screening | Correlation Between Glucose AUC and Birth Weight. | AUC-110 to birth weight centile | 0.2902 correlation coefficient |
| Continuous Glucose Monitor for Diabetes in Pregnancy Screening | Correlation Between Glucose AUC and Birth Weight. | AUC-120 to birth weight centile | 0.2935 correlation coefficient |
p-value: 0.035correlation
Secondary
Pregnancy and Delivery Characteristics for Participants With AUC-130 <= 22,000 and AUC-130 > 22,000
For our secondary outcome analyses,we chose to focus on AUC-130 because 130 mg/dL is a common threshold used when treating gestational diabetics. In addition, 130 mg/dL was the threshold used in an earlier pilot study performed at our institution because it had the best correlation with birth weight percentile. Secondary outcomes were compared between these two groups using the chi-square test. Data were analyzed using Stata 11.2. AUC-130 values were divided into high and low at a cutoff of 22,000, which was the 90th percentile of AUC-130 values.
Time frame: CGM measured 7 days at beginning of pregnancy,birth weight measured a time of delivery
Population: A total of 57 patients were enrolled from two clinical sites. Of these patients, 44 were screened with the 1-hour 50-g GCT; 9 were screened with 2-hour 75-g GTT. Complete data on secondary outcomes was available for 43 patients with 1-hour 50-g GCT and these were analyzed.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Continuous Glucose Monitor for Diabetes in Pregnancy Screening | Pregnancy and Delivery Characteristics for Participants With AUC-130 <= 22,000 and AUC-130 > 22,000 | Delivery Mode: Vaginal Delivery | 31 participants |
| Continuous Glucose Monitor for Diabetes in Pregnancy Screening | Pregnancy and Delivery Characteristics for Participants With AUC-130 <= 22,000 and AUC-130 > 22,000 | Delivery Mode: Unplanned Operative Delivery | 7 participants |
| Continuous Glucose Monitor for Diabetes in Pregnancy Screening | Pregnancy and Delivery Characteristics for Participants With AUC-130 <= 22,000 and AUC-130 > 22,000 | Macrosomia >90% | 4 participants |
| Participants With AUC 130 >22,000 | Pregnancy and Delivery Characteristics for Participants With AUC-130 <= 22,000 and AUC-130 > 22,000 | Delivery Mode: Vaginal Delivery | 5 participants |
| Participants With AUC 130 >22,000 | Pregnancy and Delivery Characteristics for Participants With AUC-130 <= 22,000 and AUC-130 > 22,000 | Delivery Mode: Unplanned Operative Delivery | 0 participants |
| Participants With AUC 130 >22,000 | Pregnancy and Delivery Characteristics for Participants With AUC-130 <= 22,000 and AUC-130 > 22,000 | Macrosomia >90% | 1 participants |