The prevalence of gestational diabetes mellitus (GDM) is rapidly increasing worldwide, particularly in low- and middle-income countries (LMICs). Tight glycemic control via diet and lifestyle modification is critical to treating GDM and preventing its adverse health consequences, including increased risk of type 2 diabetes (T2D), in women and their children. However, in many resource-limited countries including Nepal, time for diet/lifestyle counseling often competes with other components of antenatal care. Mobile health (mHealth) technology can be leveraged to promote healthy behaviors, and support self-management and treatment of GDM, but this approach has not been tried previously in any LMICs. Taking a user-centered design approach, here the study investigators propose to develop a culturally-appropriate smartphone application (app) to support self-management of GDM (GDM-DH), and test its usability and preliminary efficacy, among patients in a tertiary level, university hospital of Kathmandu University, Nepal. Based on the Social Cognitive Theory framework for behavior change, this app will assist in self-management of GDM by increasing the patient's knowledge and self-efficacy to adhere to the recommended diet and physical activity regimens. The app will also help clinicians by generating easily digestible visual displays of patient data and behaviors, which can aid in their clinical decision-making and counseling. In the requirements gathering phase, 6 GDM patients will be recruited into a focus group to view paper prototypes and provide feedback on its features and functions. Additional questions will be asked about their perceived barriers, facilitators, and strategies for lifestyle modification. Key informant interviews will also be conducted with 5 clinicians (gynecologists, dietician, physical therapist) and 3 family members, asking them to provide feedback on the GDM-DH prototype, especially pertaining to the usefulness and format of the graphic summaries of patient data. After revising paper prototypes and developing the first digital prototype, six additional patients with GDM will be recruited for two rounds of usability testing including think-aloud protocol and focus group discussions. Final prototype will be developed following an iterative process of product design and user testing. After developing the app, the investigators will recruit 120 women who are newly diagnosed with GDM, and randomly assign them to one of two treatment conditions: either (A) standard care + telemonitoring alone, or (B) GDM-DH app + standard care + telemonitoring, from 30 weeks of gestation to delivery. All participants will receive bio-monitoring devices for the self-monitoring of blood pressure and blood glucose. Although the fundamental elements of the telemonitoring support are the same between the two groups, patients in the app group will be able to leverage the technological features in the app to aid with self-monitoring.

In addition to 120 women with GDM, we will also be enrolling 100 women who do not have GDM but failed the glucose challenge test (GCT) in the first screening step of the 2-step diagnostic test for GDM. Women who had high GCT (thus failed the GCT screening) but are not diagnosed GDM are also at increased risk of adverse pregnancy outcomes and are also recommended to adopt diet/lifestyle modification in our study site (Dhulikhel Hospital). In addition to randomizing 120 GDM women in a clinical trial, we will also randomize 100 high GCT women to one of two treatment conditions: either (A) standard care alone or (B) GDM-DH app + standard care, for the rest of their pregnancies.

Block randomization will be utilized to split GDM patients and high GCT patients evenly amongst the two treatment groups. The 120 GDM women will be randomized into two groups of 60. The high GCT women will be randomized into two groups of 50. Patients in Treatment A will receive standard care alone, regardless of diagnosis. Patients in Treatment B will receive GDM-DH app + standard care. All women diagnosed with GDM will receive telemonitoring in addition to their standard care, whereas women diagnosed with high GCT only will not.