Estimating Insulin Sensitivity in Pregnancies With Type 1 Diabetes

The investigators want to learn how the body's response to insulin changes during pregnancy in people with Type 1 Diabetes.

In this study, the investigators will look at information from people who used a Dexcom continuous glucose monitor (CGM) and a Tandem insulin pump while they were pregnant. Participants will fill out an online survey and agree to share their device data. The investigators will use this information to see how insulin sensitivity changes from three months before pregnancy to six months after the baby is born.

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Key information

Conditions

Pregnancy Autoimmune Diseases Diabetes Mellitus Diabetes Mellitus, Type 1 Endocrine System Diseases Glucose Metabolism Disorders Hyperinsulinism Immune System Diseases Insulin Resistance Metabolic Diseases Nutritional and Metabolic Diseases Type 1 Diabetes (T1D)

Age range

18 year and older

Sex eligibility

Female

Study type

Observational

Primary location

Northwestern Memorial Hospital, Chicago, Illinois, United States

About this study

The aim of this retrospective observational study is to collect continuous glucose monitor (CGM) and insulin pump data from pregnant individuals with Type 1 Diabetes, from 3 months before conception to 6 months after delivery. This data will be used to estimate how insulin sensitivity (IS) changes across gestation, with the goal of better understanding glucose-insulin dynamics during pregnancy and develop algorithms for adapting insulin administration across gestational ages.

Participants will complete an online survey where they will provide their insulin pump serial number, date of delivery, gestational week at delivery, date of last menstrual cycle (if known), and other optional demographic information. The study team will use this information to retrieve participants' CGM and insulin infusion data from 3 months before conception to 6 months after delivery.

Up to 200 participants will be screened, with the goal of reaching 100 screened participants.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Age >=18 years old
Pregnant within the last 8 years
Diagnosed with type 1 diabetes for at least one year at the time of pregnancy
Use of a Dexcom CGM system (Dexcom, Inc., CA) and Tandem insulin infusion pump (Tandem Diabetes Care, CA) across gestation, and willing to share data from this pregnancy with study staff.

Treatment and study plan

Primary outcomes

Percent Time in Target Range

Time frame: Assessed every 2 weeks from 4 weeks pre-conception to 6 months post partum

Percentage of time blood glucose was 70mg/dL and 180mg/dL as per CGM

Secondary outcomes

Percent Time Below Range

Time frame: Assessed every 2 weeks from 4 weeks pre-conception to 6 months post partum

Percentage of time blood glucose was below 70mg/dL as per CGM
Percent Time Above Range

Time frame: Assessed every 2 weeks from 4 weeks pre-conception to 6 months post partum

Percentage of time blood glucose was above 180 mg/dl as per CGM

Sponsors and collaborators

Lead sponsor

University of Virginia

Other

Collaborators

Northwestern Memorial Hospital

Registry information

Official study title

Estimating Insulin Sensitivity Fluctuations Across Pregnancies With Type 1 Diabetes

Acronym: EISP

Important dates

Study start: 2026
Primary completion: 2027
Study completion: 2027
First posted: Jan 20, 2026
Registry last updated: Mar 2, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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