The investigators hypothesize that the use of a web/smartphone-based coaching program specific for the management of GDM can improve clinical outcomes among women with GDM. The investigators propose to conduct a randomised clinical trial to study the efficacy of the Habits-GDM program in clinical practice in Singapore. The primary outcome would be the percentage of patients who achieve optimal GWG (OGWG) using the US Institute of Medicine (IOM) guidelines.