Gestational diabetes (GDM) complicates about 20% of pregnancies in Singapore. These women are at high risk of developing type 2 diabetes years after pregnancy; seven times more likely than normal. Achieving a healthy weight post-delivery is key to reduce the risk of future diabetes. This study, from a multidisciplinary team, intends to create a unique seamless care model to restore optimal weight post-delivery in women with recent GDM. The innovation examined in this randomized control trial is an INTERACTIVE SMARTPHONE APP. The APP monitors weight, dietary habits, and exercise activity patterns, gives feedback, and provides practical personalized lifestyle coaching that is culturally appropriate and customized to the Singapore context. If efficacy is confirmed in this RCT, the APP can be easily scaled up as a cost-effective way to potentially prevent or delay the onset of type 2 diabetes in Singaporean women. Additionally, measurement of markers of cardiometabolic risk will give indications on future cardiovascular health, utilizing an underused opportunity to improve women's health.

About 20% of pregnant Singaporean women are diagnosed with gestational diabetes (GDM), defined as the onset of glucose intolerance that is first recognized in pregnancy. These women are at seven times higher risk of developing type 2 diabetes in the future. About 20 - 50% of women who were diagnosed with GDM during their pregnancies eventually develop type 2 diabetes, with resultant huge health care costs for Singapore and other countries globally. The Diabetes Prevention Program Study has shown that lifestyle changes resulting in modest weight loss are effective in preventing type 2 diabetes in women with a history of GDM. The investigators estimate that about 50% of all type 2 diabetes in women in Singapore occurs when they have a history of GDM and represent a sizeable subpopulation where primary prevention could have a highly significant national impact. Preliminary data indicates that after birth, women with GDM are overwhelmed with care for the newborn and tend to neglect their own health needs. They welcome reminders and coaching but are time-challenged and cannot attend regular on-site lifestyle coaching sessions.

Hypothesis:

1. Use of an INTERACTIVE SMARTPHONE APP that can track weight, diet and activity linked to an interactive lifestyle coaching intervention can restore optimal weight in women with recent GDM. The team hypothesizes that at 4 months post-delivery, participants in the intervention arm will have significantly higher probability of returning to weight at the start of pregnancy, a significantly improved cardiometabolic status and overall lower risk profile for type 2 diabetes development compared with those receiving standard care (control).
2. The use of this INTERACTIVE SMARTPHONE APP is cost-effective from the perspective of the Singapore healthcare system.

Aims:

1. To conduct a randomized control trial to examine the efficacy of an INTERACTIVE SMARTPHONE APP, customized for Singaporean women with recent GDM, in optimizing post-delivery weight and metabolic profiles compared with standard care.

   Primary outcome:

   • Restoration of booking weight if previous booking BMI ≤ 23
   • Weight loss of 5% with respect to booking weight if BMI > 23

   Secondary outcomes:

   - Improved cardiometabolic and inflammatory markers: fasting and 2h post-glucose load plasma glucose in an oral glucose tolerance test, HbA1C, advanced glycation end-products, C-peptide, HOMA-IR, lipid profile, liver function, hsCRP, IL-6.

2. Evaluate the relative cost-effectiveness of this INTERACTIVE SMARTPHONE APP compared to standard care within the Singapore healthcare system in terms of improvements in quality of life, feasibility, acceptability, scalability and sustainability.

Inclusion Criteria:

• Female aged 21 years and above
• Plans to deliver in NUH
• Diagnosed with GDM antenatally (between 24-34 weeks gestation) defined using the 2013 World Health Organization criteria (fasting plasma glucose = 5.1 mmol/L, plasma glucose at 1H <10 or plasma glucose at 2H post 75gm glucose load of =8.5 mmol/L)
• Has a smartphone and able to independently use a smartphone app
• Willing to provide a blood sample
• Able to give written informed consent
• Able to speak and read English

Exclusion Criteria:

• Subjects with type 1 and/or type 2 diabetes (including suspected cases diagnosed by an abnormal oral glucose tolerance test in the 1st and early 2nd trimesters of pregnancy)
• drugs that affect glucose or lipid metabolism (e.g. systemic steroids, metformin, insulin, statins, orlistat)
• terminal or life threatening condition
• physical or mental condition that would prevent completion of a majority of study instruments.

The subjects who participate in the study may be seeing the doctors or allied health professionals involved in this study at the clinic. However, recruitment will not be done by them though they will help to improve the awareness of such a study to their patients. There will be no coercion involved as the subjects have the full autonomy to decide if they wish to participate.