Relevance: There is an urgent need to effectively support Diabetes mellitus type 1 (T1DM) women who are either TP or PP in their efforts to achieve and maintain strict glycemic control without experiencing SH. The investigators propose to test an Internet-based training program (Bump2be.org) to assist these women better anticipate, detect, manage, and prevent extreme BG occurrences to enable them to meet their glycemic goals for pregnancy. If found efficacious, Bump2be will be the first Internet-based behavioral intervention to train and assist these women achieve the recommended glycemic targets without increasing their risk of SH. The program has the potential to impact its target patients on a major public health level by supplementing their preconception care with a conveniently accessible program tailored to their specific needs. It holds promise to improve not only their BG management but also psychosocial functioning (e.g., reduced fear of hypoglycemia, improved diabetes-related quality of life and knowledge) with no additional burden on the healthcare system.