Restricted accessResearch articleFirst published online 2026-1
Practical Approach to Continuous Glucose Monitoring Interpretation and Automated Insulin Delivery Use in Pregnancy: Considerations for Obstetric Providers
While automated insulin delivery (AID) systems have multiple well-established benefits outside of pregnancy and are widely used in non-pregnant individuals with type 1 diabetes (T1D), none of the commercially available AID systems in North America are approved for use during pregnancy. Use of commercially available AID systems off-label in pregnancy is currently limited by: (1) glucose targets higher than the fasting glucose target range recommended during pregnancy and (2) algorithms which were not designed for the dynamic changes in insulin resistance which occur across gestation. However, as AID use in the general population expands, many individuals will opt to continue using these systems off-label during pregnancy, and thus, guidance for providers regarding AID use and optimization during pregnancy is of the utmost importance. A cornerstone to the effective use of AID systems is the systematic and accurate interpretation of continuous glucose monitoring (CGM) data. One obstacle to the use of both CGM and AID systems by obstetric providers is the lack of comfort with CGM interpretation. We therefore present here: (1) a systematic approach to CGM interpretation during pregnancy and (2) practical guidance regarding AID use during pregnancy for individuals who opt to use commercially available AID systems off-label during pregnancy after consideration of individualized risks and benefits.
American College of Obstetricians Gynecologists’ Committee on Practice Bulletins. ACOG practice bulletin no. 201: pregestational diabetes mellitus. Obstet Gynecol. 2018;132(6):e228-e48. doi:10.1097/AOG.0000000000002960.
2.
TundidorDMeekCLYamamotoJ, et al. Continuous glucose monitoring time-in-range and HbA(1c) targets in pregnant women with type 1 diabetes. Diabetes Technol Ther. 2021;23(10):710-714. doi:10.1089/dia.2021.0073.
3.
PolskySWuMBodeBW, et al. Diabetes technology use among pregnant and nonpregnant women with T1D in the T1D exchange. Diabetes Technol Ther. 2018;20(8):517-523. doi:10.1089/dia.2018.0033.
4.
SzmuilowiczEDBarbourLBrownFM, et al. Continuous glucose monitoring metrics for pregnancies complicated by diabetes: critical appraisal of current evidence. J Diabetes Sci Technol. 2024;18(4):819-834. doi:10.1177/19322968241239341.
5.
MurphyHR. Continuous glucose monitoring targets in type 1 diabetes pregnancy: every 5% time in range matters. Diabetologia. 2019;62(7):1123-1128. doi:10.1007/s00125-019-4904-3.
6.
BattelinoTDanneTBergenstalRM, et al. Clinical targets for continuous glucose monitoring data interpretation: recommendations from the international consensus on time in range. Diabetes Care. 2019;42(8):1593-1603. doi:10.2337/dci19-0028.
7.
American Diabetes Association Professional Practice Committee. 15. Management of diabetes in pregnancy: standards of care in diabetes-2025. Diabetes Care. 2025;48(suppl 1):S306-S20. doi:10.2337/dc25-S015.
8.
American Diabetes Association Professional Practice Committee. 7. Diabetes technology: standards of care in diabetes-2025. Diabetes Care. 2025;48(suppl 1):S146-S66. doi:10.2337/dc25-S007.
9.
MurphyHRScottEM. Demarcating the benefits of hybrid closed loop therapy in pregnant women with type 1 diabetes. Lancet Diabetes Endocrinol. 2024;12(6):368-369. doi:10.1016/S2213-8587(24)00104-9.
10.
BenhalimaKBeunenKVan WilderN, et al. Comparing advanced hybrid closed loop therapy and standard insulin therapy in pregnant women with type 1 diabetes (CRISTAL): a parallel-group, open-label, randomised controlled trial. Lancet Diabetes Endocrinol. 2024;12(6):390-403. doi:10.1016/S2213-8587(24)00089-5.
11.
PolskySBuschurEDunganK, et al. Randomized trial of assisted hybrid closed-loop therapy versus sensor-augmented pump therapy in pregnancy. Diabetes Technol Ther. 2024;26(8):547-555. doi:10.1089/dia.2024.0012.
LeeTTMCollettCBergfordS, et al. Automated insulin delivery in women with pregnancy complicated by type 1 diabetes. N Engl J Med. 2023;389(17):1566-1578. doi:10.1056/NEJMoa2303911.
14.
LevyCJKudvaYCOzaslanB, et al. At-home use of a pregnancy-specific zone-MPC closed-loop system for pregnancies complicated by type 1 diabetes: a single-arm, observational multicenter study. Diabetes Care. 2023;46(7):1425-1431. doi:10.2337/dc23-0173.
15.
SzmuilowiczEDLevyCJBuschurEOPolskyS. Expert guidance on off-label use of hybrid closed-loop therapy in pregnancies complicated by diabetes. Diabetes Technol Ther. 2023;25(5):363-373. doi:10.1089/dia.2022.0540.
16.
SzmuilowiczEDAleppoG. Stepwise approach to continuous glucose monitoring interpretation for internists and family physicians. Postgrad Med. 2022;134(8):743-751. doi:10.1080/00325481.2022.2110507.
LawGREllisonGTSecherAL, et al. Analysis of continuous glucose monitoring in pregnant women with diabetes: distinct temporal patterns of glucose associated with large-for-gestational-age infants. Diabetes Care. 2015;38(7):1319-1325. doi:10.2337/dc15-0070.
24.
KristensenKÖggeLESengpielV, et al. Continuous glucose monitoring in pregnant women with type 1 diabetes: an observational cohort study of 186 pregnancies. Diabetologia. 2019;62(7):1143-1153. doi:10.1007/s00125-019-4850-0.
25.
ScottEMFeigDSMurphyHRLawGR; CONCEPTT Collaborative Group. Continuous glucose monitoring in pregnancy: importance of analyzing temporal profiles to understand clinical outcomes. Diabetes Care. 2020;43(6):1178-1184. doi:10.2337/dc19-2527.
26.
MeekCLTundidorDFeigDS, et al. Novel biochemical markers of glycemia to predict pregnancy outcomes in women with type 1 diabetes. Diabetes Care. 2021;44(3):681-689. doi:10.2337/dc20-2360.
27.
ScottEMMurphyHRKristensenKH, et al. Continuous glucose monitoring metrics and birth weight: informing management of type 1 diabetes throughout pregnancy. Diabetes Care. 2022;45(8):1724-1734. doi:10.2337/dc22-0078.
28.
SanusiAAXueYMcIlwraithC, et al. Association of continuous glucose monitoring metrics with pregnancy outcomes in patients with preexisting diabetes. Diabetes Care. 2023;47(1):89-96. doi:10.2337/dc23-0636.
29.
RademakerDvan der WelAWTvan EekelenR, et al. Continuous glucose monitoring metrics and pregnancy outcomes in insulin-treated diabetes: a post-HOC analysis of the GlucoMOMS trial. Diabetes Obes Metab. 2023;25(12):3798-3806. doi:10.1111/dom.15276.
30.
LawGRAlnajiAAlrefaiiL, et al. Suboptimal nocturnal glucose control is associated with large for gestational age in treated gestational diabetes mellitus. Diabetes Care. 2019;42(5):810-815. doi:10.2337/dc18-2212.
31.
HernandezTLBarbourLA. A standard approach to continuous glucose monitor data in pregnancy for the study of fetal growth and infant outcomes. Diabetes Technol Ther. 2013;15(2):172-179. doi:10.1089/dia.2012.0223.
MurphyHRElleriDAllenJM, et al. Pathophysiology of postprandial hyperglycaemia in women with type 1 diabetes during pregnancy. Diabetologia. 2012;55(2):282-293. doi:10.1007/s00125-011-2363-6.
35.
International Diabetes Center. About AGP—the single page report for everyone 2024. Accessed November 5, 2024. http://www.agpreport.org/agp/about
36.
ZismanAMoralesFStewartJStuhrAVlajnicAZhouR. BeAM value: an indicator of the need to initiate and intensify prandial therapy in patients with type 2 diabetes mellitus receiving basal insulin. BMJ Open Diabetes Res Care. 2016;4(1):e000171. doi:10.1136/bmjdrc-2015-000171.
BolliGBPerrielloGFanelliCGDe FeoP. Nocturnal blood glucose control in type I diabetes mellitus. Diabetes Care. 1993;16(suppl 3):71-89. doi:10.2337/diacare.16.3.71.
39.
CarlsonALGrahamTEAkturkHK, et al. Control-IQ technology use in individuals with high insulin requirements: results from the multicenter Higher-IQ trial. J Diabetes Sci Technol. 2024;18(6):1288-1292. doi:10.1177/19322968241234072.
40.
WangXSDunlopADMcKeenJAFeigDSDonovanLE. Real-world use of Control-IQ technology automated insulin delivery in pregnancy: a case series with qualitative interviews. Diabet Med. 2023;40(6):e15086. doi:10.1111/dme.15086.
41.
YamamotoJMBenhamJMohammadKDonovanLEWoodS. Intrapartum glycaemic control and neonatal hypoglycaemia in pregnancies complicated by diabetes: a systematic review. Diabet Med. 2018;35(2):173-183. doi:10.1111/dme.13546.
42.
Diabetes Canada Clinical Practice Guidelines Expert Committee; FeigDSBergerHDonovanLGodboutA, et al. Diabetes and pregnancy. Can J Diabetes. 2018;42(suppl 1):S255-S282. doi:10.1016/j.jcjd.2017.10.038.
43.
DashoraULevyNDhatariyaK, et al. Managing hyperglycaemia during antenatal steroid administration, labour and birth in pregnant women with diabetes—an updated guideline from the Joint British Diabetes Society for Inpatient Care. Diabet Med. 2022;39(2):e14744. doi:10.1111/dme.14744.
44.
DreverETomlinsonGBaiADFeigDS. Insulin pump use compared with intravenous insulin during labour and delivery: the INSPIRED observational cohort study. Diabet Med. 2016;33(9):1253-1259. doi:10.1111/dme.13106.
45.
BeunenKGillardPVan WilderN, et al. Advanced hybrid closed-loop therapy compared with standard insulin therapy intrapartum and early postpartum in women with type 1 diabetes: a secondary observational analysis from the CRISTAL randomized controlled trial. Diabetes Care. 2024;47(11):2002-2011. doi:10.2337/dc24-1320.
American Diabetes Association Professional Practice Committee. 16. Diabetes care in the hospital: standards of care in diabetes-2025. Diabetes Care. 2025;48(suppl 1):S321-S34. doi:10.2337/dc25-S016.
48.
AchongNDuncanELMcIntyreHDCallawayL. Peripartum management of glycemia in women with type 1 diabetes. Diabetes Care. 2014;37(2):364-371. doi:10.2337/dc13-1348.
49.
DonovanLEFeigDSLemieuxP, et al. A randomized trial of closed-loop insulin delivery postpartum in type 1 diabetes. Diabetes Care. 2023;46(12):2258-2266. doi:10.2337/dc23-0882.
50.
GrunbergerGAbelsethJMBaileyTS, et al. Consensus statement by the American Association of Clinical Endocrinologists/American College of Endocrinology insulin pump management task force. Endocr Pract. 2014;20(5):463-489. doi:10.4158/EP14145.PS.
51.
AchongNDuncanELMcIntyreHDCallawayL. The physiological and glycaemic changes in breastfeeding women with type 1 diabetes mellitus. Diabetes Res Clin Pract. 2018;135:93-101. doi:10.1016/j.diabres.2017.11.005.
52.
ButteNFKingJC. Energy requirements during pregnancy and lactation. Public Health Nutr. 2005;8(7A):1010-1027. doi:10.1079/phn2005793.
53.
GuJChaputKHDunlopABoothJFeigDSDonovanLE. Existing standardised questionnaires do not adequately capture quality-of-life outcomes of greatest importance for those living with type 1 diabetes in pregnancy. Diabet Med. 2023;40(4):e15044. doi:10.1111/dme.15044.
54.
DonovanLEBellRCFeigDS, et al. Glycaemic patterns during breastfeeding with postpartum use of closed-loop insulin delivery in women with type 1 diabetes. Diabetologia. 2024;67(10):2154-2159. doi:10.1007/s00125-024-06227-z.
