Postpartum Dysglycemia Screening With Continuous Glucose Monitoring
Phase: NA
Conditions: Gestational Diabetes
Sponsor: Icahn School of Medicine at Mount Sinai

Postpartum Dysglycemia Screening With Continuous Glucose Monitoring 
PI: Grenye O'Malley, MD
NCT05714761
Document Date: 12/21/2022

Postpartum dysglycemia screening with Dexcom G6 
Version 1.1
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10 September 2020
NIH-FDA Clinical Trial Protocol Template – v1.0 2017-04-07
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Postpartum dysglycemia screening with continuous 
glucose monitoring 
Principal Investigator: Grenye O'Malley
Draft Number: 1.1
8 December 2020
Summary of Changes from Previous Version:
Affected 
Section(s)
Summary of Revisions Made
Rationale
Table of Contents
Statement of Compliance..............................................................................................................................................3
1 Protocol Summary......................................................................................................................................................4
1.1 Synopsis...............................................................................................................................................................4
1.2 Schema ................................................................................................................................................................5
1.3 Schedule of Activities (SoA).................................................................................................................................5
2 Introduction................................................................................................................................................................7
2.1 Study Rationale....................................................................................................................................................7
2.2 Background..........................................................................................................................................................7
2.3 Risk/Benefit Assessment .....................................................................................................................................8
2.3.1 Known Potential Risks ..................................................................................................................................8
2.3.2 Known Potential Benefits .............................................................................................................................8
3 Objectives and Endpoints.........................................................................................................................................10
4 Study Design.............................................................................................................................................................12
4.1 Overall Design....................................................................................................................................................12
5 Study Population ......................................................................................................................................................14
5.1 Inclusion Criteria................................................................................................................................................14
5.2 Exclusion Criteria ...............................................................................................................................................14
5.3 Lifestyle Considerations.....................................................................................................................................14
5.4 Screen Failures...................................................................................................................................................14
5.5 Strategies for Recruitment and Retention.........................................................................................................14
6 Study Intervention Discontinuation and Participant Discontinuation/Withdrawal .................................................15
6.1 Discontinuation of Study Intervention ..............................................................................................................15
6.2 Participant Discontinuation/Withdrawal from the Study..................................................................................15
6.3 Lost to Follow-Up...............................................................................................................................................15
7 Study Assessments and Procedures .........................................................................................................................16
7.1 Adverse Events and Serious Adverse Events .....................................................................................................16
7.1.1 Definition of Adverse Events (AE)...............................................................................................................16
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7.1.2 Definition of Serious Adverse Events (SAE) ................................................................................................16
7.1.3 Classification of an Adverse Event..............................................................................................................17
7.1.4 Adverse Event Reporting............................................................................................................................17
8 Statistical Considerations .........................................................................................................................................18
8.1 Sample Size Determination ...............................................................................................................................18
8.2 Statistical Analyses ............................................................................................................................................18
8.2.1 Analysis of the Primary Efficacy Endpoint(s) ..............................................................................................18
8.2.2 Analysis of the Secondary Endpoint(s) .......................................................................................................18
8.2.3 Safety Analyses...........................................................................................................................................18
8.2.4 Exploratory Analyses ..................................................................................................................................18
9 Supporting Documentation and Operational Considerations ..................................................................................19
9.1 Regulatory, Ethical, and Study Oversight Considerations .................................................................................19
9.1.1 Informed Consent Process..........................................................................................................................19
9.1.2 Confidentiality and Privacy.........................................................................................................................19
9.2 Abbreviations ....................................................................................................................................................19
9.3 Protocol Amendment History............................................................................................................................20
11 References..............................................................................................................................................................21
Effective Date: 12/21/2022
End Date:12/20/2023

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STATEMENT OF COMPLIANCE
1.
The trial will be carried out in accordance with International Council on Harmonisation Good 
Clinical Practice (ICH GCP) and the following:
o
United States (US) Code of Federal Regulations (CFR) applicable to clinical studies (45 CFR Part 
46, 21 CFR Part 50, 21 CFR Part 56, 21 CFR Part 312, and/or 21 CFR Part 812).
Investigators and clinical trial site staff who are responsible for the conduct, management, or 
oversight of NIH-funded clinical trials have completed Human Subjects Protection and ICH GCP 
Training.
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Postpartum dysglycemia screening with Dexcom G6 
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1 PROTOCOL SUMMARY
1.1 SYNOPSIS
Title:
Postpartum dysglycemia screening with continuous glucose monitoring 
Study 
Description:
Gestational diabetes (GDM) is one of the most common complications of 
pregnancy, and up to one third of women with GDM will have abnormal 
blood sugars after their pregnancy. To screen for abnormal blood sugars, 
standard of care is a 6-12 week postpartum oral glucose tolerance test 
(OGTT). However only 17-60% of women actually have this test performed. 
This study is to assess the feasibility of using a continuous glucose monitor 
placed on discharge from the hospital after delivery as a screening method to 
detect postpartum abnormal blood sugars. 
Objectives:
Primary Objective:
To assess the feasibility of continuous glucose 
monitoring compared to oral glucose tolerance testing 
for the diagnosis of postpartum diabetes in women 
with recent gestational diabetes.
Secondary Objectives: To evaluate the specificity, sensitivity, positive 
predictive value, and negative predictive value of 
continuous glucose monitoring compared to oral 
glucose tolerance testing for the diagnosis of 
postpartum dysglycemia in women with recent 
gestational diabetes.
To evaluate the influence of predictors of lack of 
postpartum oral glucose tolerance testing on 
completion of postpartum continuous glucose 
monitoring.
Endpoints:
Primary Endpoint: 
Percentage of participants with at least 72 hours of 
CGM data downloaded.
Secondary Endpoints: CGM acceptability scoring
Specificity, sensitivity, PPV, and NPV for CGM 
compared to OGTT will be performed for diagnosis 
of DM, IGT, and IFG
Study 
Population:
Pregnant or recently pregnant women who were diagnosed with GDM during 
current/recent pregnancy. 
Target enrollment: 50 participants
 
Sites/Facilities 
Enrolling 
Participants:
Icahn School of Medicine at Mount Sinai
Effective Date: 12/21/2022
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Description of 
Study 
Intervention:
Women will be consented and screened before or after delivery. They will be 
asked about medical history, medications, and diabetes risk factors. A 
Dexcom Professional CGM will be placed on postpartum day 1-3. 
Participants will wear the sensor for 10 days and return it at their postpartum 
visit or by mail. They will be given another sensor to place before their 
standard of care OGTT and will mail the sensor back after that test is 
performed. 
Study Duration:  1 years
Participant 
Duration:
 Up to 20 weeks
 
1.2 SCHEMA
3rd 
trimester/1-3 
days 
postpartum: 
Women with 
GDM 
consented and 
screened
1-3 days 
postpartum:
Sensor 
placement
1-2 weeks 
postpartum:
CGM returned 
by visit or mail
4-12 weeks 
postpartum:
Sensor 
placement
OGTT
CGM returned 
by visit or mail
1.3 SCHEDULE OF ACTIVITIES (SOA)
Visit
1
2
3
4
Home
5
Timing
Third 
trimester or 
1-3 days 
postpartum
1-3 days 
postpartum
1-4 weeks 
postpartum
4-12 weeks 
postpartum
4-12 weeks 
postpartum
2-5 days 
before OGTT
4-12 weeks 
postpartum
Setting
In person or 
telehealth
Postpartum 
floor or 
telehealth
In person or 
telehealth
Telehealth
Telehealth or 
in person
Consent
X
Medical history
X
Pregnancy/Fetal 
outcome 
questions
X
X
Professional 
sensor training
X
X
X
Effective Date: 12/21/2022
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Sensor 
placement
X
X
Return of 
sensor
X
X
Skin assessment
X
X
Questionnaire
X
X
OGTT reminder 
call
X
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2 INTRODUCTION
2.1 STUDY RATIONALE
Gestational diabetes (GDM) is one of the most common complications of pregnancy. Up to one 
third of women with GDM will have persistently abnormal blood sugars postpartum, and up to 
70% will develop diabetes later in life. In order to diagnose persistent postpartum dysglycemia 
and future risk of type 2 diabetes, the American Diabetes Association (ADA), American College 
of Obstetrics and Gynecology (ACOG), and World Health Organization (WHO) recommend that 
all women with GDM undergo an oral glucose tolerance test (OGTT) at 6-12 weeks postpartum 
[1-3]. However, this screening occurs in less than half of women diagnosed with GDM. Thus, 
standard of care for screening for postpartum dysglycemia is not occurring for the majority of 
women. A more feasible and convenient alternative for screening is needed. This study aims to 
assess the feasibility of continuous glucose monitoring (CGM) compared to OGTT for the 
diagnosis of postpartum dysglycemia in women with recent GDM.
2.2 BACKGROUND
Though considered the standard of care, postpartum OGTT screening for women with GDM is 
not performed in the majority of women. Previous research has tried to address promotion and 
incentivizing of OGTT testing, but has only achieved screening rates of up to 60% [5]. 
Alternative testing strategies have failed to achieve the desired feasibility and predictive value 
needed. The goal of this study is to assess the feasibility of a postpartum 10 day CGM study for 
detection of postpartum diabetes, impaired glucose tolerance (IGT), and impaired fasting glucose 
(IFG). CGM will be placed on discharge from the hospital and worn for 10 days. CGM will be 
returned at approximately 2 weeks postpartum at routine obstetrics or pediatric visits, or by mail. 
Postpartum CGM has the potential to greatly increase adherence rates to postpartum testing 
compared to 6-12 week OGTT. The secondary objectives of this study are to assess the 
sensitivity and specificity of postpartum CGM compared to standard of care OGTT and to assess 
for predictors of non-completion.
GDM is common and is a risk factor for future dysglycemia. GDM complicates 7% of 
pregnancies and is one of the most common complications of pregnancy [2]. Though for many 
women GDM resolves at delivery, up to one third of women with GDM will have diabetes or 
IGT at postpartum screening, and up to 70% will develop diabetes later in life [2]. Early 
diagnosis of dysglycemia allows early interventions which have been shown to decrease the risk 
of progression from IGT to diabetes, including weight loss, physical activity, breastfeeding, and 
pharmacologic interventions [6]. Postpartum screening can also be an opportunity to optimize 
health before future pregnancies to decrease the risk of maternal and fetal complications in 
addition to the long term risks of diabetes. Newly discovered, previously undiagnosed type 2 
diabetes is associated with previous history of GDM, and is associated with increased perinatal 
risks when compared with GDM including perinatal mortality (OR 2.3), preterm birth (OR 2.6), 
congenital anomalies (OR 2.1), neonatal intensive care unit admission (OR 3.1) and neonatal 
hypoglycemia (OR 406) [7]. 
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Standard of care for postpartum screening is not met by the majority of women who are at high 
risk to continue to have dysglycemia. Screening for diabetes and IGT using a 75-g, 2 hour OGTT 
is recommended by obstetric and endocrinology societies including ADA, ACOG, and WHO at 
6-12 weeks postpartum [1-3, 8]. Unfortunately, postpartum screening at this time only occurs in 
17-60% of women even during studies designed to promote testing [9-11]. In a randomized 
control trial, Clark et al found that postal reminders to patients and physicians in led to an 
increase in screening by one year postpartum with 14.3% tested by one year with no reminder, 
51.6% with a reminder to the physician, 55.3% with reminder to patient, and 60.5% with 
reminder to physician and patient (p<0.05) [5]. Implementation of this strategy at two Canadian 
hospital systems did increase rates of screening, but not as robustly as seen in the original 
randomized control trial described above [9], with 28% OGTT completion by 6 months with 
reminders compared with 14% completion with usual care (p=0.1) [12]. The DIAMIND study in 
Australia found that a reminder at six weeks did not increase screening by six months postpartum 
[13]. Multiple interventions have been studied at Mount Sinai Hospital: after implementation of 
an advanced order set at the 35-week pregnancy visit, provider education modules, and 
nutritionist phone calls reminding patients to fast before postpartum testing, OGTT test 
completion in association with a six week postpartum visit increased from 17% to 36% (p=0.01) 
[10]. 
Increased interaction with a healthcare system and health literacy are associated with higher 
likelihood of postpartum testing [9, 11]. The strongest predictor of effective postpartum diabetes 
screening is attendance at postpartum healthcare visits [9]. The influence of race and ethnicity on 
postpartum screening rates is not consistent across studies [14], but in general there are strong 
associations of poor postpartum screening compliance with minority race, ethnicity, younger age, 
mental health disorders, and lower health literacy [11]. These disparities contribute to higher 
rates of undiagnosed diabetes in these populations which will have long term consequences on 
the women and their communities. During the COVID-19 pandemic, screening recommendations 
and adherence rates have changed further. For example, in the United Kingdom, Canada, and 
Australia, alternative and less testing have been recommended [15]. In the United States, no 
change in guidelines has been formally proposed; if it were, it could be expected to lead to 
further declines in postpartum screening, as women with lower health literacy and less access to 
healthcare having poorer follow up.
Alternative testing has not been able to replace postpartum OGTT. In theory, simpler screening 
tests might be considered, but these have proven inferior to the OGTT for postpartum 
dysglycemia screening. For example, fasting glucose values alone fail to capture some women 
with IGT and diabetes. A meta-analysis found a fasting glucose had a sensitivity of 16-89% 
compared to OGTT (the best sensitivity was a study performed 4-8 years after delivery) [16]. 
Hemoglobin A1C (HbA1C) measurements might seem a reasonable surrogate screening tool, but 
HbA1C can be lowered by increased red blood cell turnover during recent pregnancy and 
peripartum blood loss [3, 17]. One year after delivery, HbA1C compared to an OGTT has a 
reported sensitivity of 22.64% and PPV of 54.55% [17]. 
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Multiple strategies have been explored to address this challenge. The selection of 6-12 weeks 
postpartum for the standard of care OGTT is mostly historical based on assumptions of changes 
in hormonal activity. However, markers of insulin sensitivity and production have been found to 
improve by postpartum days 1-5 (median day tested: postpartum day 2) [18]. The authors of that 
study concluded that the majority of improvements in metabolism occur in the immediate 
postpartum period [18]. An analysis of multiple studies looking at the accuracy of immediate 
postpartum OGTT before hospital discharge found good specificity (95.7%) and negative 
predictive value (NPV) (98.1%) for diabetes diagnosis, but performed sub-optimally when IFG 
and IGT were included (specificity 50.5%, NPV 75.3%) [19]. For women who receive steroids 
before or during labor, the impact on blood glucose levels would still be present on hospital day 
2, so postpartum days 3-10 would likely perform better. 
CGM for screening for dysglycemia in other populations. Chen et al found a strong correlation 
between CGM values and venous blood values during OGTT testing in otherwise healthy 
participants with fasting blood glucoses between 70-200 mg/dL [20]. In other populations where 
HbA1C cannot be depended on for diabetes diagnosis, such thalassemia, use of CGM for 
diagnosis has been studied [21]. CGM detected more IGT and diabetes than OGTT in a study of 
cystic fibrosis patients [22].
CGM metrics in healthy volunteers have been established. Analysis of CGM in participants 
without diabetes has found very low percentages of time above 180mg/dL (median 0%, IQR 0-
0.2%), above 160mg/dL (median 0.3%, IQR 0.1-0.9%), and above 140 mg/dL (median 2.1%, 
IQR 0.9-3.9%) [23]. Overnight monitoring, defined as midnight to 5:59am, the rates of time 
above these thresholds were even lower (IQR ranges 0-0%, 0-0%, and 0-1%, respectively), and 
time spent in the range 70-120mg/dL was 94% (IQR 88-97%) [23].
2.3 RISK/BENEFIT ASSESSMENT
2.3.1 KNOWN POTENTIAL RISKS
Participants using the CGM will be at low risk for developing a local skin infection at the site of 
the sensor needle placement.  If a catheter is left under the skin for more than 24 hours it is 
possible to get an infection where it goes into the skin, with swelling, redness and pain.  There 
may be bleeding where the catheter is put in and bleeding under the skin causes a bruise (1 in 10 
risk).  In less than 1 out of 500 participants the CGM might break and leave a small portion of 
the sensor under the skin that may cause redness, swelling or pain at the insertion site. 
Some participants may develop skin irritation or allergic reactions to the adhesives used to secure 
the CGM.  If these reactions occur, different adhesives or "under-taping" (such as with IV 3000, 
Tegaderm, etc.) will be tried, sites will be rotated frequently, and a mild topical steroid cream or 
other medication may be required. 
Whenever the skin is broken there is the possibility of an infection.  The CGM sensors are 
inserted under the skin.  It is possible that any part that is inserted under the skin may cause an 
infection.  These occur very infrequently, but, if an infection was to occur, oral and/or topical 
antibiotics can be used. 
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Data downloaded from the CGM will be collected for the study as measures of diabetes self-
management behaviors.  Some people may be uncomfortable with the researchers' having such 
detailed information about their daily diabetes habits.
Loss of confidentiality is a potential risk; however, standard operating procedures will be 
followed as detailed in section 9.1.2 to minimize this risk.
2.3.2 KNOWN POTENTIAL BENEFITS
This study is not designed with the purpose of providing personal direct benefit to the 
participants. CGM data can be shared with the participant or their providers after their OGTT at 
the participant’s request which could provide benefit to the participant. 
It is expected that this protocol will yield increased knowledge about the feasibility of using 
CGM as a screening tool for DM after GDM. If this is feasible, screening could increase in 
frequency and ease. 
Effective Date: 12/21/2022
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3 OBJECTIVES AND ENDPOINTS
OBJECTIVES
ENDPOINTS
JUSTIFICATION FOR 
ENDPOINTS
Primary
To assess the feasibility of continuous 
glucose monitoring compared to oral 
glucose tolerance testing for the 
diagnosis of postpartum diabetes in 
women with recent gestational 
diabetes.
Percentage of participants 
with at least 72 hours of 
CGM data downloaded.
72 hours of data has been 
accepted as sufficient for 
identifying CGM trends
Secondary
To evaluate the specificity, sensitivity, 
positive predictive value, and negative 
predictive value of continuous glucose 
monitoring compared to oral glucose 
tolerance testing for the diagnosis of 
postpartum dysglycemia in women 
with recent gestational diabetes.
CGM acceptability scoring
Specificity, sensitivity, 
PPV, and NPV for CGM 
compared to OGTT will be 
performed for diagnosis of 
DM, IGT, and IFG
Of participants who receive 
standard of care, the CGM 
data will be compared to the 
standard of care to assess 
specificity, sensitivity, PPV, 
and NPV
Tertiary/Exploratory
Association of risk factors with 
nonadherence to postpartum OGTT.
A secondary analysis will be 
performed in which we remove any 
data within 4 half-lives of last know 
steroid exposure. 
Sensitivity and specificity of DM, 
IGT, and IFG for sensor worn at the 
time of postpartum OGTT will be 
explored. 
Demographics, CGM 
return, OGTT completion
Specificity, sensitivity, 
PPV, and NPV for CGM 
compared to OGTT will be 
performed for diagnosis of 
DM, IGT, and IFG 
excluding data within 4 
half-lives of last known 
steroid exposure.
CGM data from 4-12 weeks 
postpartum will be 
compared to the immediate 
postpartum CGM data and 
to the postpartum OGTT.  
Demographic data will be 
analyzed to assess if similar 
populations complete CGM 
vs OGTT
Steroids affect blood sugar. 
This exploratory analysis 
will help to determine if this 
needs to be considered when 
using CGM to assess for 
postpartum dysglycemia.
Stability of CGM trends 
over the postpartum weeks 
will be assessed, and CGM 
data from the same time as 
OGTT will be compared. 
 
 
 
Effective Date: 12/21/2022
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4 STUDY DESIGN
4.1 OVERALL DESIGN
The goal of this study is to assess the feasibility of the use of CGM for detection of postpartum 
diabetes, IGT, and IFG. Women with a diagnosis of GDM in their current or recent pregnancy 
will be recruited, and a Dexcom Professional CGM will be placed on postpartum day 0-3 and 
worn for ten days. This period of time would be less influenced by peripartum glucocorticoid use 
than an OGTT on hospital day 2. The CGM device will be returned at around two weeks at the 
routine postpartum obstetrics visits, at routine pediatric visits, or by mail. This ease of device 
return has the potential to greatly increase the adherence rates to postpartum testing, as compared 
to returning for the standard 6-12 week OGTT. The rates of CGM return, acceptability of system 
use by participants, sensitivity, specificity, PPV, NPV, and predictors of non-completion will be 
analyzed.
Visit 1: Women with a diagnosis of GDM in their current or recent pregnancy will be identified 
from physician referral and labor and delivery floor trackers. Inclusion criteria include diagnosis 
of gestational diabetes during a current or recent pregnancy and age 18 or older. Exclusion 
criteria include known pregestational diabetes, known skin adhesive allergy which would prevent 
subject from wearing a CGM, and chronic glucocorticoid use which is planned to be ongoing 
after labor and delivery discharge. They will be invited to participate and consented at their 
obstetrics or endocrinology visits during their third trimester or during admission for delivery. 
This visit can be performed in person or remotely. Medical history, medications, GDM diagnosis 
timing and values, age, race and ethnicity, education level, insurance type, parity, estimated pre-
pregnancy weight and BMI, history of GDM in prior pregnancies, history of hypertension, other 
pregnancy complications, and family history will be recorded. If Visit 2 is planned to be 
performed remotely, Dexcom Pro training and supplies will be provided at this visit.
Visit 2: Visit 2 can be performed in conjunction with Visit 1 if the participant is already 
postpartum at recruitment or as a separate visit. It can be performed on the postpartum floor or 
remotely. The participant will be asked about pregnancy and delivery complications, GDM 
management, number of prenatal obstetric visits, estimated pregnancy weight gain, delivery 
weight and body mass index, gestational age at delivery, delivery method, steroid administration 
within the past week, fetal weight and complications, HbA1C values if available, and 
hemoglobin values. Participants will be asked for permission for access to review and record 
their future OGTT results. A Dexcom G6 Pro (or Dexcom G7 if FDA approved and available at 
the time of study) will be placed on an approved body site. The devices will be supplied by 
Dexcom at no cost to the subject. The participant will be trained on appropriate care of the sensor 
and removal. 
Home use: Participants will wear the sensor for ten days or less if there is a sensor failure or the 
device is dislodged. After ten days, the participant will remove the sensor.
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Visit 3: Visit 3 will occur 1-4 weeks after sensor placement. This visit can coincide with the 
participant’s obstetrics or pediatric visit and can be performed in person or remotely. The 
participant will return the sensor at this visit, or mail the sensor to the study team within thirty 
days of placement. Postpartum complications and method of infant feeding obtained as part of 
normal postpartum care will be recorded. Participants will be asked whether they snack 
overnight and typical timing of breakfast, and the research team will determine what hour of the 
day would be considered fasting. If a participant is never fasting for over six hours, she will be 
considered to have not completed a fasting state. The investigator will assess for skin reaction at 
the sensor site. Participants will be asked about their experience and acceptability of blinded 
CGM.  Participants will be encouraged to undergo the standard of care 6-12 week postpartum 
OGTT. Participants will be provided with another sensor to be placed before OGTT, and 
application will be reviewed. 
Visit 4: Visit 4 will be conducted remotely. Participants will be contacted by text or phone call to 
encourage them to undergo the standard of care OGTT. If a participant is unable to have an 
OGTT performed through her normal care, she can have an optional in-person visit to have it 
performed at the study site. All participants will be instructed to place a Dexcom sensor at least 
48 hours prior to their planned OGTT. 
Home use: Participants will wear the sensor for at least 48 hours before planned OGTT for a 
total of ten days or less if there is a sensor failure or the device is dislodged. After ten days, the 
participant will remove the sensor. 
Visit 5: Visit 5 will be conducted remotely after the 6-12 week OGTT. Participants will be 
instructed to mail the sensor back to the study team in pre-addressed, prepaid packaging. The 
investigator will assess for skin reaction at sensor site. Participants will be asked about their 
experience and acceptability of OGTT testing. Results of the OGTT will be recorded. If it is 
performed at an outside facility, the participant will request that the records be shared with the 
research team. Results of CGM data may be shared with a participant and her providers if 
requested by the participant after her routine OGTT. Investigators will not provide results before 
this to decrease risk of participants not completing the standard of care OGTT.
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5 STUDY POPULATION
5.1 TARGET ENROLLMENT
50 participants
5.2 INCLUSION CRITERIA
Pregnant or delivered within the past 3 days
Diagnosis of gestational diabetes during current pregnancy
Age 18 or older
5.3 EXCLUSION CRITERIA
Pregestational diabetes
Known skin adhesive allergy
Chronic steroid use which will be ongoing after hospital discharge
5.4 LIFESTYLE CONSIDERATIONS
Trends in use of telehealth have been incorporated into this protocol to accommodate maximum 
number of participants.
5.5 SCREEN FAILURES
If participant meets an exclusion criteria after enrollment, such using steroids, their data will not 
be included in analysis. 
5.6 STRATEGIES FOR RECRUITMENT AND RETENTION
Since up to 40% of women do not attend any postpartum visits [11], our study recruitment and 
retention will need to be optimized. Participants will be recruited from their routine obstetrics 
and endocrinology visits and also from the postpartum labor and delivery floor. Consent will be 
translated into Spanish, and interpreters will be used to increase potential recruitment and recruit 
a more diverse and representative study population. We believe the availability of remote visits 
will decrease burden on participants, will increase retention for women who do not wish attend 
postpartum visits, and will address potential limitations on research visits at study sites due to 
COVID-19 concerns. The option for visit 2 to be performed either on the postpartum floor or 
remotely will allow recruitment of women who are delivering at multiple locations. 
Compensation will be provided for time and effort. Participants will receive $25 after Visit 1, 
$75 after Visit 3 and an additional $125 after completion of their standard OGTT. We estimate 
that 50% of participants will complete their standard OGTT with reminders and incentives; the 
enrollment goals have been planned accordingly.
Effective Date: 12/21/2022
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6 STUDY INTERVENTION DISCONTINUATION AND PARTICIPANT 
DISCONTINUATION/WITHDRAWAL
6.1 DISCONTINUATION OF STUDY INTERVENTION
Participants will be withdrawn from the study without their consent if the participant indicates 
they are not willing or not able to wear the study device for at least 72 hours. If participant has an 
adverse skin reaction but have collected 72 hours of data, they can continue in the study and may 
forego the second CGM placement if they prefer.
6.2 PARTICIPANT DISCONTINUATION/WITHDRAWAL FROM THE STUDY
Participants can withdraw from the study at any time if they so wish. If a participant decides to 
withdraw their permission and disclosure of their Protected Health information from the study, 
she will need to do so in writing to the principal investigator Dr. Grenye O’Malley.
6.3 LOST TO FOLLOW-UP
Based on previous literature, we estimate that 50% of participants will complete their standard 
OGTT with reminders and incentives; the enrollment goals have been planned accordingly. 
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7 STUDY ASSESSMENTS AND PROCEDURES
7.1 ADVERSE EVENTS AND SERIOUS ADVERSE EVENTS
7.1.1 DEFINITION OF ADVERSE EVENTS (AE)
To ensure consistency of adverse event causality assessments, investigators will apply the 
following general guideline when determining whether an adverse event is related.  An adverse 
event is considered related if there is a plausible temporal relationship between the onset of the 
adverse event and the study intervention, and the adverse event cannot be readily explained by 
the participant's clinical state, intercurrent illness, or concomitant therapies; and/or the adverse 
event follows a known pattern of response to the study intervention; and/or the adverse event 
abates or resolves upon discontinuation of the study intervention or dose reduction and, if 
applicable, reappears upon re-challenge. 
An adverse event is considered unrelated if evidence exists that the adverse event has an etiology 
other than the study intervention (e.g., preexisting medical condition, underlying disease, 
intercurrent illness, or concomitant medication); and/or the adverse event has no plausible 
temporal relationship to study intervention.
7.1.2 DEFINITION OF SERIOUS ADVERSE EVENTS (SAE)
 The intensity of adverse events will be rated on a three-point scale: (1) mild, (2) moderate, or (3) 
severe.  It is emphasized that the term severe is a measure of intensity: thus, a severe adverse 
event is not necessarily serious. For example, itching for several days may be rated as severe, but 
may not be clinically serious.
Adverse events will be coded using the MedDRA dictionary.
All adverse events including adverse events that continue after the study participant's 
discontinuation or completion of the study will be followed until their medical outcome is 
determined or until no further change in the condition is expected.
Reporting Serious Adverse Events, Unexpected Adverse Device Effects
Any untoward occurrence that:
•
Results in death.
•
Results in transmission of a bloodborne pathogen.
•
Is life-threatening; (a non-life-threatening event which, had it been more severe, might 
have become life-threatening, is not necessarily considered a serious adverse event).
•
Requires inpatient hospitalization or prolongation of existing hospitalization.
•
Results in persistent or significant disability/incapacity or substantial disruption of the 
ability to conduct normal life functions.
•
Is a congenital anomaly or birth defect
•
Is considered a significant medical event by the investigator based on medical judgment 
(e.g., may jeopardize the participant or may require medical/surgical intervention to prevent one 
of the endpoints listed above).
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7.1.3 CLASSIFICATION OF AN ADVERSE EVENT
 An Unanticipated Adverse Device Effect is defined as any serious adverse effect on health or 
safety or any life-threatening problem or death caused by, or associated with, a device, if that 
effect, problem, or death was not previously identified in nature, severity, or degree of incidence 
in the investigational plan or application (including a supplementary plan or application), or any 
other unanticipated serious problem associated with a device that relates to the rights, safety, or 
welfare of subjects.”
 
7.1.4 ADVERSE EVENT REPORTING
 All unanticipated and/or adverse events will be reported to the IRB and sponsor.
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8 STATISTICAL CONSIDERATIONS
8.1 SAMPLE SIZE DETERMINATION
This is a pilot study so previous data to inform sample size is limited. Group size is based on 
previous feasibility studies [19, 24]. The secondary outcomes will be used to develop 
preliminary data for power calculations for a future study powered to calculate accuracy of CGM 
testing compared to standard of care postpartum OGTT.
8.2 STATISTICAL ANALYSES
8.2.1 ANALYSIS OF THE PRIMARY EFFICACY ENDPOINT(S)
Percentage of participants with at least 72 hours of CGM data downloaded. 
8.2.2 ANALYSIS OF THE SECONDARY ENDPOINT(S)
Specificity, sensitivity, PPV, and NPV for CGM compared to OGTT will be performed for 
diagnosis of DM, IGT, and IFG. Percentage of participants categorized as CGM-IFG, CGM-IGT 
and CGM-DM will be reported.
8.2.3 SAFETY ANALYSES
 Percentage of participants with skin reactions will be reported. 
8.2.4 EXPLORATORY ANALYSES
A secondary analysis will be performed in which we remove any data within 4 half-lives of last 
know steroid exposure. 
CGM data from 4-12 weeks postpartum will be compared to the immediate postpartum CGM 
data and to the postpartum OGTT.  
Sensitivity and specificity of DM, IGT, and IFG for sensor worn at the time of postpartum 
OGTT will be explored.
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9 SUPPORTING DOCUMENTATION AND OPERATIONAL CONSIDERATIONS
9.1 REGULATORY, ETHICAL, AND STUDY OVERSIGHT CONSIDERATIONS
9.1.1 INFORMED CONSENT PROCESS
Consent will be obtained prior to any study assessments/procedures. The investigator will 
approach eligible potential participants and explain the study in a private area, including the 
reasons why participants are eligible, risks and benefits and the regimens to be evaluated. The 
patient will have as much time as needed to review the consent form.  All study related questions 
will be answered prior to the patient signing the consent form.  The patient will be provided a 
contact number for the study nurse practitioner and research coordinator which can be used 
during business hours as well as contact number to have a member of the study team paged after 
hours if needed. Participants’ privacy interests are always considered from the time participants 
are identified for recruitment until they have completed the study. If screening visit is conducted 
via telehealth, standard operating procedures for remote consent will be followed. 
9.1.1.1 CONSENT/ASSENT AND OTHER INFORMATIONAL DOCUMENTS PROVIDED TO 
PARTICIPANTS
Copy of signed consent
User guide for Dexcom Professional CGM
9.1.2 CONFIDENTIALITY AND PRIVACY
Only research personnel involved in the conduct of this research will have access to identifiable 
information and will be communicating with participants throughout the trial. When trying to get 
in contact with participants through mail or phone messages etc., the utmost discretion will be 
utilized. 
Participants will on enrollment be given a unique study ID and all of their information recorded 
will be de-identified. Information provided to the sponsor will only label participants by study 
ID. The information to link participants to their study ID will only be accessed by the study 
team.  Computers used for research purposes at Mount Sinai that store study data are encrypted 
through Academic Computing. Data management will be performed on approved research tools 
such as RedCap. All study participant binders are double locked in the research coordinators 
office which is only accessible to members of the study team.
9.1.3 STUDY RECORDS RETENTION
 Shredded after 10 years of study completion
9.2 ABBREVIATIONS
AE
Adverse Events
ACOG
American College of Obstetrics and Gynecology
ADA
American Diabetes Association
CFR
Code of Federal Regulations
CGM
Continuous glucose monitoring
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GGM-IFG
CGM-based impaired fasting glucose
CGM-IGT
CGM-based impaired glucose tolerance
CGM-DiabetesCGM-based diabetes
CGM-normal Normal CGM profile
GDM
Gestational diabetes
ICH GCP
International Council on Harmonisation Good Clinical Practice
IFG
impaired fasting glucose
IGT
impaired glucose tolerance
IQR
Interquartile range
NPV
Negative predictive value
OGTT
Oral glucose tolerance test
OR
Odds ratio
PPV
Positive predictive value
SoA
Schedule of Activities
SAE
Serious Adverse Events
US
United States
WHO
World Health Organization
9.3 PROTOCOL AMENDMENT HISTORY
Version
Date
Description of Change 
Brief Rationale
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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