Glycemic Profiles And Insulin Delivery Across The Menstrual Cycle In Women With Type 1 Diabetes

Inclusion Criteria: * Type 1 diabetes for at least 12 months * Use of glucose sensor in the last 6 months * Use of insulin pump in the last 6 months * Age ≥18 to ≤40 years * HbA1c ≤8.5% if measured at screening or available from historical medical report performed within the last 6 months; in absence of a valid HbA1c measurement, average blood glucose estimated from CGM data to be approximately 200 mg/dL or less * Absence of perimenopausal/menopausal symptoms * Willingness to keep track of beginning of menstrual cycle * Willingness to keep track of ingested carbohydrates * Willingness to not become pregnant during study participation * Regularly menstruating (at least every month with no missed cycles) * Only free-cycling participants: willingness to use ovulation kits to confirm ovulation * Only participants under oral contraceptive therapy: use of monophasic pill, with 3 weeks of active pill and 1 week of placebo * Willingness to use the study Dexcom G6 during the study * Participants must have Internet access and a computer system that meets the requirements for uploading the study equipment Exclusion Criteria: * Pregnancy * Hormonal birth control therapy except monophasic pill contraceptive * Polycystic ovary syndrome (PCOS) diagnosis * Current use of steroids * Concurrent use of any non-insulin glucose-lowering agent (including GLP-1 agonists, pramlintide, DPP-4 inhibitors, SGLT-2 inhibitors, sulfonylureas, metformin) * Uncontrolled thyroid disease * Active fertility treatment * Concomitant disease or condition that may compromise patient safety or ability to follow the protocol including: planned or current dialysis treatment; moderate to advanced nephropathy; known or suspected allergy to medical grade adhesives. * Severe hypoglycemia or diabetes ketoacidosis (DKA) in the previous 6 months