The goal of this trial is to compare different means of glucose monitoring in women with gestational diabetes and a history of gastric bypass surgery. The main question it aims to answer is: How does continous glucose monitoring impact the treatment and affect pregnancy outcome in these women. Participants will be randomized to either continous glucose monitoring or regular capillary glucose measurements during the last trimester of their pregnancy. Researchers will compare the glucose measurement outcomes, the glucose lowering treatment given and pregnancy outcomes between groups.