The patients are asked to answer a validated questionnaire about mild and severe hypoglycemia and hypoglycemia-associated factors such as blood glucose level during hypoglycemia, the degree of awareness, pregnancy-associated nausea and vomiting, insulin type and dose etc. Other medication, exercise habits, coffee- and alcohol intake, smoking and social status will be recorded. In case of severe hypoglycemia a structured interview concerning the episode will be performed within 24 hours. Blood glucose, HbA1c, the degree of insulin resistance and the levels of IGF1, placenta growth hormone and of the renin-angiotensin-system will be monitored.