1383-P: Longitudinal Observation of Insulin Use and Glucose Time-in-Range in T1D Pregnancy
Authors: O’MALLEY GRENYE , OZASLAN BASAK , LEVISTER CAMILLA , TRINIDAD MARI CHARISSE , CASTORINO KRISTIN N. , DESJARDINS DONNA , CHURCH MEI MEI , SMITH BYRON H. , OGYAADU SELASSIE J. , PIPER MOLLY , REID COREY , MCCRADY-SPITZER SHELLY K. , KAUR RAVINDER JEET , KREMERS WALTER K. , DOYLE FRANCIS J. , PINSKER JORDAN E. , LEVY CAROL J. , ROSENN BARAK , KUDVA YOGISH C. , DASSAU EYAL 
Published: June 2020

The target time in range (TIR) for pregnant women with type 1 diabetes (T1D) by the International Consensus on TIR is 70% between 63-140 mg/dL. This is difficult to achieve and is rarely met in the literature. Insulin use increases during pregnancy, but prospective data and guidance on pump setting adjustments are limited. Insulin pump delivery and CGM data for 17 T1D women from 3 U.S. sites were prospectively collected every 2 weeks as part of the LOIS-P trial. Subjects enrolled before 17 weeks gestational age (GA) and wore personal pumps and study Dexcom G6 CGM. Changes in mean daily total, basal and bolus doses per kilogram, and TIR for every 2 weeks GA are reported, and linear mixed effects regression models are used for evaluation across trimesters. Enrollment HbA1C was 6.4±0.8%. Total daily dose increased from 0.68 to 0.73 to 0.98 U/kg during the first, second and third trimesters, respectively (p&lt;0.01). Basal dose increased from 0.31 to 0.36 to 0.44 (p&lt;0.01). Bolus dose increased from 0.37 to 0.37 to 0.54 (p&lt;0.01). Daily TIR was 68%, 60% and 63% (p=0.9), with 29% of subjects achieving &gt;70% TIR during pregnancy. Time below target was 5%, 4% and 2%. Doses trended upwards around 24 weeks GA. Postpartum doses decreased significantly. While insulin doses were increased significantly across pregnancy, most subjects did not achieve &gt; 70% TIR. Systems that are customized to this population’s targets with changing insulin sensitivity are needed.

Disclosure
G. O’Malley: Research Support; Self; Abbott, Dexcom, Inc. B. Ozaslan: None. C. Levister: None. M. Trinidad: None. K.N. Castorino: Research Support; Self; Abbott, Dexcom, Inc., Medtronic, Mylan, Novo Nordisk Inc. D. Desjardins: None. M. Church: None. B.H. Smith: None. S.J. Ogyaadu: None. M. Piper: None. C. Reid: None. S.K. McCrady-Spitzer: None. R. Kaur: None. W.K. Kremers: Research Support; Self; AstraZeneca. F.J. Doyle: Research Support; Self; DreaMed Diabetes, Tandem Diabetes Care, Xeris Pharmaceuticals, Inc. Stock/Shareholder; Self; Mode AGC. Other Relationship; Self; Dexcom, Inc., Insulet Corporation, Roche Diabetes Care. J.E. Pinsker: Advisory Panel; Self; Medtronic. Consultant; Self; Eli Lilly and Company, Tandem Diabetes Care. Research Support; Self; Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Tandem Diabetes Care. Speaker’s Bureau; Self; Tandem Diabetes Care. C.J. Levy: Consultant; Self; Dexcom, Inc. Employee; Spouse/Partner; Allergan plc. Research Support; Self; Abbott, Dexcom, Inc., Insulet Corporation. B. Rosenn: None. Y.C. Kudva: Research Support; Self; Dexcom, Inc., Roche Diabetes Care. Other Relationship; Self; Abbott. E. Dassau: Consultant; Self; Eli Lilly and Company. Research Support; Self; Dexcom, Inc., DreaMed Diabetes, Tandem Diabetes Care, Xeris Pharmaceuticals, Inc. Speaker’s Bureau; Self; Roche Diabetes Care. Other Relationship; Self; Dexcom, Inc., Insulet Corporation, Roche Diabetes Care.

Funding
National Institutes of Health (R01DK120358); Dexcom, Inc. (AP-2018-016)