Postpartum Continuous Glucose Monitoring (CGM) Study

This research study is being done to assess if using a glucose sensor (also known as a continuous glucose monitor) after childbirth can help identify women who are at risk of developing diabetes after having diabetes during pregnancy or gestational diabetes. Currently, screening for diabetes after childbirth is performed with an oral glucose tolerance test 6-12 weeks after delivery, but this is burdensome. This study will use a glucose sensor worn on the skin for 10 days. The data from the sensor will be compared to the standard oral glucose tolerance test. This is a single site study at the Icahn School of Medicine at Mount Sinai. The research team plans to enroll 50 participants aged 18years or older into the study. Participation in the study is expected to last up to 20 weeks and involves 4-5 visits depending on if enrollment is in the 3rd trimester of pregnancy or immediate postpartum. Study procedures include 1. Consent & screening. 2.Sensor placement and download after 10 days of wear. 3. a second sensor placement 2-5 days before OGTT.

Specificity for CGM compared to oral glucose tolerance test for diagnosis of diabetes, impaired glucose tolerance and impaired fasting glucose. The specificity of a test is the proportion of people who test negative among all those who actually do not have that disease.

Sensitivity for CGM compared to oral glucose tolerance test for diagnosis of diabetes, impaired glucose tolerance and impaired fasting glucose. The sensitivity of a test is the proportion of people who test positive among all those who actually have the disease.

PPV for CGM compared to oral glucose tolerance test for diagnosis of diabetes, impaired glucose tolerance and impaired fasting glucose. Positive predictive value is the probability that following a positive test result, that individual will truly have that specific disease.

NPV for CGM compared to oral glucose tolerance test for diagnosis of diabetes, impaired glucose tolerance and impaired fasting glucose. Negative predictive value is the probability that following a negative test result, that individual will truly not have that specific disease.

Inclusion criteria: include diagnosis of gestational diabetes during a current or recent pregnancy age 18 or older. Exclusion criteria: include known pregestational diabetes, known skin adhesive allergy which would prevent subject from wearing a CGM, chronic glucocorticoid use which is planned to be ongoing after labor and delivery discharge.