In the UK population in the past, at 10 years, about 50% of ladies with GDM had progressed to diabetes, but more recently in the USA Hispanic population, it was 70% at 7 years.
So some of the risk relates to your underlying risk of diabetes, as stated above, eg family history and ethnicity.
Wise to do the lifestyle to avoid DM such as keeping weight down and 30 mins exercise 5 days per week which are well validated in several diabetes prevention programs for people with Impaired Glucose Tolerance (one type of pre-diabetes).
Best wishes