The PPCGMS Intervention After GDM Trial

Among women who experience glucose abnormalities during pregnancy, screening during the postpartum period offers a window of opportunity for early identification of diabetes and prediabetes. The rates of postpartum type 2 diabetes (T2D) screening with an OGTT for women with GDM are not optimal given the majority of women with GDM fail to return for postpartum glucose testing. Continuous glucose monitoring (CGM) systems have been recognized as an ideal method of monitoring glycemic control in diabetic patients. CGM has been used in diabetic patients primarily as a management tool allowing a more acceptable and reliable glucose reading and control than self-monitoring of blood glucose (SMBG). There is a need to improve diabetes testing after childbirth in women who experienced gestational diabetes. This will allow investigators to target their efforts to improve the early diagnosis and treatment of diabetes following GDM. No studies conducted to date have not comprehensively examined whether CGM after delivery can be used in women with a recent history to predict their risk of diabetes. This research study is being done to assess the acceptability, feasibility, and accuracy of using a glucose sensor (also known as a continuous glucose monitor or CGM) after childbirth as a diagnostic test that can help identify women who are at risk of developing diabetes after having gestational diabetes and explore its correlation to the standard postpartum oral glucose tolerance test as well as a HbA1c and fructosamine test.

Given the damaging effect of prolonged undetected hyperglycemia, prevention and early diagnosis of T2D is cost-saving and of public health importance. Currently, screening for diabetes after childbirth is performed with an oral glucose tolerance test 4-16 weeks after delivery, but this is burdensome and most patients are non-compliant. This study will use a CGM worn on the skin for 10 days. The data from the sensor will be compared to the standard oral glucose tolerance test as well as a HbA1c and fructosamine test. This is a single site study from patients with recent GDM that attended the diabetes clinic at Woman's Hospital. This is a prospective observational study of fifty postpartum women with a recent GDM pregnancy. The research team plans to enroll 50 participants aged 18 years or older into the study. Participation in the study is expected to last up to 10 days during the postpartum interval. Study procedures include; 1) consent and screening; and 2) sensor placement and download after 10 days of wear postpartum during which an OGTT, fructosamine and HbA1c test will be administered. All participants will be requested to return at 4-16 weeks postpartum for a 75 gm 2-hour OGTT as part of standard care after gestational diabetes. Study participants with a history of GDM will be enrolled to use a blinded continuous glucose monitor (Dexcom G7). All CGM data will be masked and therefore not available to participants, clinicians, or researchers in real time. Participants otherwise will receive standard clinical care. All participants will be recruited from the Woman's Hospital Diabetes Clinic or from the maternal fetal medicine practice referring to the clinic. Subjects who wish to participate will provide written informed consent. The Woman's Hospital Institutional Review Board (WHIRB) will have approved both the protocol and consent. All participants will undergo a verbal screen, and if they are eligible and sign a medical release form, their medical records will be obtained to confirm their medical history. After consenting, demographic data, gravidity, parity, and body mass index (BMI) will obtained. The patient's physician will be notified of participation in the study and have access to the laboratory result.

Eligibility Criteria:
Inclusion Criteria:

* diagnosis of gestational diabetes during recent pregnancy (4-24 weeks)
* age 18 or older.
* written informed consent

Exclusion Criteria:

* pregestational diabetes (type 1 or type 2)
* include known known skin adhesive allergy which would prevent subject from wearing a CGM,
* history of bariatric surgery or other surgeries that induce malabsorption
* long-term use (\>2 weeks) of systemic steroids during the testing interval
* inability or refusal to comply with protocol