Glycemic patterns throughout pregnancy are not well described, particularly early pregnancy. CGM used throughout the gestational period in uncomplicated pregnancies may help describe glycemic patterns in more detail. Blinded CGM data were collected throughout pregnancy from 760 pregnant patients ≥18 years old, with HbA1c <6.5%, no known diabetes, and gestational age <17 weeks. CGM data from uncomplicated pregnancies (pregnancy without gestational diabetes, large for gestational age birth, or hypertensive disorder of pregnancy) established the normative data set. Uncomplicated pregnancies (n=427, mean±SD age 32±4 years, 73% White non-Hispanic, mean HbA1c 5.1±0.3%) showed mean glucose during the entire gestational period was 99±7 mg/dL. Trimester specific mean glucose was: 103±7, 98±7 and 98±8 mg/dL for 1st, 2nd, 3rd trimesters. Figure 1 shows mean glucose by hour/trimester. Median (quartiles) percent time in range (TIR) 63-120 mg/dL was 86% (82-89%) for gestational period, and 84% (79-89%), 87% (82-90%), and 85% (80-90%) for 1st, 2nd, 3rd trimesters. Figure 2 shows TIR 63-120 mg/dL by 4-week periods. In uncomplicated pregnancies, mean glucose and TIR 63-120 mg/dL remained consistent throughout the gestational period. These normative CGM data will help set pregnancy-specific glycemic targets and will be important to compare to those 333 women in this study with complicated pregnancies. Disclosure A.L.Carlson: Advisory Panel; MannKind Corporation, Novo Nordisk, Research Support; Abbott Diabetes, Dexcom, Inc., Eli Lilly and Company, Medtronic, Novo Nordisk, Insulet Corporation, UnitedHealth Group, Sanofi. J.Sibayan: None. P.Calhoun: None. C.Durnwald: None. R.Beck: Consultant; Eli Lilly and Company, Novo Nordisk, Diasome, Insulet Corporation, Research Support; Tandem Diabetes Care, Inc., Beta Bionics, Inc., Dexcom, Inc., Bigfoot Biomedical, Inc., Medtronic, Ascensia Diabetes Care, Roche Diabetes Care, Eli Lilly and Company, Novo Nordisk. Z.Li: None. E.Norton: None. R.M.Bergenstal: Advisory Panel; Abbott Diabetes, Eli Lilly and Company, Medtronic, Novo Nordisk, Roche Diabetes Care, Zealand Pharma A/S, Consultant; Ascensia Diabetes Care, Bigfoot Biomedical, Inc., CeQur SA, Dexcom, Inc., Hygieia, Onduo LLC, Sanofi, Vertex Pharmaceuticals Incorporated, Research Support; Abbott Diabetes, Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Novo Nordisk, Sanofi, UnitedHealth Group. M.L.Johnson: Research Support; Abbott, Lilly, Insulet Corporation, NIH - National Institutes of Health, Patient-Centered Outcomes Research Institute, Novo Nordisk, Tandem Diabetes Care, Inc., Medtronic, Hemsley Charitable Trust, Jaeb Center for Health Research. S.Dunnigan: None. M.Banfield: None. K.J.Krumwiede: None. Funding The Leona M. and Harry B. Helmsley Charitable Trust; United Health Group