Inclusion Criteria:  Age 18-45 years and with a singleton pregnancy with ultrasound-confirmed gestational age up to 11 weeks and 6 days for the group with bariatric surgery: history of gastric bypass (RYBG) or sleeve gastrectomy (SG) Participants need to speak and understand Flemish, French or English and have e-mail access.  Exclusion Criteria:  multiple pregnancy pregnancy ≥12 weeks other types of bariatric surgery than RYBG or SG known pregestational diabetes a physical or psychological disease likely to interfere with the conduct of the study medications known to interfere with glucose metabolism.