{"id":99167,"date":"2024-10-09T16:42:24","date_gmt":"2024-10-09T15:42:24","guid":{"rendered":"https:\/\/touchendocrinology.com\/?p=99167"},"modified":"2024-11-01T16:57:28","modified_gmt":"2024-11-01T16:57:28","slug":"use-of-automated-insulin-delivery-in-pregnancies-complicated-by-type-1-diabetes","status":"publish","type":"post","link":"https:\/\/touchendocrinology.com\/diabetes\/journal-articles\/use-of-automated-insulin-delivery-in-pregnancies-complicated-by-type-1-diabetes\/","title":{"rendered":"Use of Automated Insulin Delivery in Pregnancies Complicated by Type 1 Diabetes"},"content":{"rendered":"
The prevalence of diabetes during pregnancy is rapidly increasing. In the USA alone, an estimated 1\u20132% of pregnant women have type 1 diabetes (T1D) or type 2 diabetes (T2D), and an additional 6\u20139% develop gestational diabetes.1<\/sup><\/span><\/sup>\u00a0From 2000 to 2010, the prevalence of gestational diabetes increased by 56%, and the prevalence of existing diabetes among pregnant women increased by 37%.2<\/sup><\/span><\/sup><\/p>\nDiabetes during pregnancy is associated with significant maternal and foetal health risks, typically relating to the degree of hyperglycaemia and chronic diabetes comorbidities.3<\/sup><\/span><\/sup>\u00a0Adverse foetal outcomes include foetal and neonatal loss, congenital abnormalities, premature deliveries, macrosomia, neonatal hypoglycaemia and neonatal respiratory distress syndrome. Additionally, the rates of perinatal mortality among women with either T1D or T2D are three to four times higher than among the general obstetric population.4<\/sup><\/span><\/sup>\u00a0Maternal complications include hypertension, haemolysis, pre-eclampsia, elevated liver enzymes, Caesarean section and hypoglycaemia.5<\/sup><\/span><\/sup>\u00a0A growing body of evidence suggests that greater\u00a0time in range<\/span>\u00a0<\/span>(TIR), denoting the percentage of time spent in the target blood glucose range of 63\u2013140 mg\/dL in pregnancy, is associated with a decreased risk of adverse neonatal outcomes.6<\/sup><\/span><\/sup><\/p>\nInsulin requirements during pregnancy change drastically, with dramatic variations even within a single day, due to shifts in insulin sensitivity.7<\/sup><\/span><\/sup>\u00a0This necessitates careful monitoring and glycaemic management, especially given that diabetic ketoacidosis in pregnancy is associated with high rates of foetal loss.8<\/sup><\/span><\/sup><\/p>\nAlthough advanced diabetes technologies, such as automated insulin delivery (AID) systems or hybrid closed-loop systems, do not have the US\u00a0Food and Drug Administration<\/span>\u00a0(FDA) indications for use in pregnancy, efforts to research AID use in pregnancy are expanding, as continuous glucose monitors (CGMs) alone have shown to be beneficial but insufficient in maintaining optimal glucose control.9<\/sup><\/span><\/sup>\u00a0The CamAPS FX system, manufactured by CamDiab\u00a0<\/span>Ltd<\/span>\u00a0based in Cambridge, UK, is the only AID system approved in the UK, EU and USA for use during pregnancy.10<\/sup><\/span>\u00a0The National Institute for Health and Care Excellence has recommended AID for all people with T1D with an\u00a0Hb<\/span>A1c >8%, including pregnant women with diabetes.11<\/sup><\/span><\/sup>\u00a0The approval and recommendations are based on a series of trials showing that day-and-night closed-loop insulin delivery in pregnant women with T1D led to significantly less hypoglycaemia than sensor-augmented pump (SAP) insulin delivery.12\u201314<\/sup><\/span>\u00a0<\/sup><\/sup><\/sup>Moreover, overnight closed-loop insulin delivery resulted in significantly greater TIR compared with SAP.13\u201315<\/sup><\/span><\/sup>\u00a0SAP includes an insulin pump with the use of a CGM, but insulin delivery is not automatically adjusted based on sensor glucose values.<\/sup>\u00a0Notably, the\u00a0Automated Insulin Delivery Amongst Pregnant Women With Type 1 Diabetes <\/span>(AiDAPT; ClinicalTrials.gov Identifier<\/span>:<\/span>\u00a0NCT04938557<\/span>) trial in pregnant women with T1D, randomized to use the CamAPS FX system or a standard insulin pen or pump with a CGM, showed that participants using the CamAPS FX system spent an additional 2.5 h\/day in range.16<\/sup><\/span>\u00a0The use of the CamAPS FX system during pregnancy also improved maternal and neonatal outcomes. Positive maternal outcomes included reduced maternal weight gain and reduced cases of hypertensive disorders, including worsening hypertension, new-onset hypertension and pre-eclampsia. On the neonatal side, there was a significant decrease in gestational age at delivery, along with a smaller percentage of children considered large or extremely large for gestational age. Of note, this system is able to set a glucose target as low as 80 mg\/dL, while FDA-approved systems can only be set to a target as low as 100 mg\/dL, and many systems have higher targets than that.16<\/sup><\/span><\/sup><\/p>\nMost recently, the use of Medtronic\u2019s (Minneapolis, Minnesota<\/span>) MiniMed 780G system was shown in the\u00a0Closed-loop Insulin Delivery in Pregnant Women With Type 1 Diabetes<\/span>\u00a0(CRISTAL;\u00a0ClinicalTrials.gov Identifier<\/span>:<\/span>\u00a0NCT04520971<\/span>) trial (n=89),<\/sup>\u00a0presented at the 17th International Conference on Advanced Technologies and Treatments for Diabetes and published in\u00a0The Lancet Diabetes & Endocrinology<\/em>, to improve overnight TIR while reducing hypoglycaemia in pregnant women with T1D.17,18<\/sup><\/span><\/sup>\u00a0The trial, however, failed to meet the primary endpoint of overall TIR, which might reflect the cohort\u2019s low baseline HbA1c of 6.5%, as well as the inability to lower the system\u2019s glucose target to under 100 mg\/dL. The trial did show a statistically significant improvement in overnight TIR. Due to the algorithm\u2019s meal-assisted technology and ability to subtract insulin even with more intensive carbohydrate ratios, users were recommended to enter additional carbohydrates beyond what they were eating. In findings consistent with the AiDAPT trial, fewer individuals on AID experienced excessive gestational weight gain compared with those on standard care. A smaller observational study<\/sup>\u00a0evaluating MiniMed 780G in 13 pregnant women with T1D showed a significant increase in TIR and a decrease in HbA1c throughout pregnancy; however, there were high rates of maternal and neonatal complications, with five women having pre-eclampsia and nine women undergoing a Caesarean section.19<\/sup><\/span><\/sup><\/p>\nPrior to the approval of MiniMed 780G and the CRISTAL trial, several case reports demonstrated the successful use of Medtronic\u2019s MiniMed 670G in pregnancy.20\u201322<\/sup><\/span><\/sup><\/sup><\/sup> In one pregnant woman with T1D using MiniMed 670G, Guzm\u00e1n<\/span>\u00a0G\u00f3mez\u00a0et al<\/span>. found improved glycaemic control, fewer severe hypoglycaemia and hyperglycaemia events and no neonatal or obstetric complications.22<\/sup><\/span>\u00a0Similarly, in another case, after the initiation of MiniMed 670G following the detection of an unplanned pregnancy in a woman with T1D and with a baseline HbA1c level of 7.1%, TIR increased by 4.5%, HbA1c level remained at about 6.5% throughout the pregnancy and no safety events were reported.20<\/sup><\/span><\/p>\nLimitations for using AID in pregnancy centre on the stricter glycaemic targets in pregnancy,<\/sup>\u00a0as current FDA-approved algorithms do not target these glucose levels.23<\/sup><\/span>\u00a0The American Diabetes Association (ADA) defines standard targets in pregnancy as fasting plasma glucose <95 mg\/dL and either 1\u00a0<\/span>h postprandial glucose <140 mg\/dL or 2\u00a0<\/span>h postprandial glucose <120 mg\/dL.24<\/sup><\/span>\u00a0It also recommends an HbA1c target in pregnancy of <6% if it can be achieved without significant hypoglycaemia.<\/p>\nExpert guidance<\/sup>, published last year, offers a framework for off-label use of AID during pregnancy.25<\/sup><\/span>\u00a0The guidance provides several recommendations, including using the lowest target glucose available for the system in use, correcting for hypoglycaemia often but carefully to avoid overcorrection and thus rebound hyperglycaemia, administering extra insulin boluses when needed and adjusting carbohydrate-to-insulin ratios regularly throughout the pregnancy to meet changing insulin needs. Ultimately, while the guidance offers possible pregnancy adjustments for commercially available AID systems, it emphasizes that there is no \u2018one-size-fits-all\u2019 approach and calls for individualized medicine, involving flexibility and frequent reassessment.<\/p>\nAccordingly, small studies have investigated pregnancy-specific AID algorithms. In a pilot study, Ozaslan et al. evaluated a zone model predictive control (MPC) algorithm in 11 pregnant women with T1D and showed improved TIR with no serious adverse events.26<\/sup><\/span><\/sup>\u00a0In another study of a zone MPC algorithm customized for pregnancy in 10 women, Levy et al. showed improved TIR, along with decreases in\u00a0time above range (TAR)<\/span>\u00a0and\u00a0<\/span>time below ran<\/span>ge (TBR). Nine participants achieved >70% TIR.27<\/sup><\/span><\/sup><\/p>\nTo better characterize the use of AID in pregnancy, we present a retrospective case review of six pregnant women with T1D who used an AID system off-label during pregnancy. This includes two Insulet Omnipod 5 users, two Tandem t:slim X2 Control-IQ users and two Do-It-Yourself (DIY) or open-source loop users.\u00a0Table 1<\/em><\/span>\u00a0describes the key characteristics of each system. We describe glycaemic outcomes and insulin requirements throughout the pregnancies.<\/p>\n\n
Table 1: <\/span>An overview of automated insulin delivery systems available in the USA<\/p>\n\n
\n\n\n\n AID system<\/b><\/p>\n<\/td>\n | \n Omnipod 5<\/b><\/p>\n<\/td>\n | \n Control-IQ<\/b><\/p>\n<\/td>\n | \n DIY Open-Source Loop<\/b><\/p>\n<\/td>\n | \n MiniMed 670<\/b>G<\/b><\/p>\n<\/td>\n | \n MiniMed 770<\/b>G<\/b><\/p>\n<\/td>\n | \n MiniMed 780<\/b>G<\/b><\/p>\n<\/td>\n | \n iLet<\/b><\/p>\n<\/td>\n<\/tr>\n<\/thead>\n\n\n\n Company<\/b><\/p>\n<\/td>\n | \n Insulet<\/p>\n<\/td>\n | \n Tandem<\/p>\n<\/td>\n | \n N\/A<\/p>\n<\/td>\n | \n Medtronic<\/p>\n<\/td>\n | \n Medtronic<\/p>\n<\/td>\n | \n Medtronic<\/p>\n<\/td>\n | \n Beta Bionics<\/p>\n<\/td>\n<\/tr>\n | \n\n CGM<\/b><\/p>\n<\/td>\n | \n Dexcom G6<\/p>\n<\/td>\n | \n Dexcom G6, Dexcom G7 or FreeStyle Libre 2 Plus<\/p>\n<\/td>\n | \n Dexcom G6, Dexcom G7, Dexcom ONE, Libre sensors in dev branch only and Medtronic sensors connected to a\u00a0l<\/span>oop-compatible Medtronic pump<\/p>\n<\/td>\n | \n Guardian 3<\/p>\n<\/td>\n | \n Guardian 3<\/p>\n<\/td>\n | \n Guardian 3 and Guardian 4<\/p>\n<\/td>\n | \n Dexcom G6<\/p>\n<\/td>\n<\/tr>\n | \n\n Pump<\/b><\/p>\n<\/td>\n | \n The Pod<\/p>\n<\/td>\n | \n t:slim X2 or Mobi (only compatible with Dexcom G6)<\/p>\n<\/td>\n | \n Medtronic 515 or 715 (any firmware), Medtronic 522 or 722 (any firmware), Medtronic 523 or 723 (firmware 2.4 or lower), Medtronic Worldwide Veo 554 or 754 (firmware 2.6A or lower), Medtronic Canadian\/Australian Veo 554 or 754 (firmware 2.7A or lower), Omnipod Eros (no longer available in the USA) and Omnipod DASH<\/p>\n<\/td>\n | \n MiniMed 670G<\/p>\n<\/td>\n | \n MiniMed 770G<\/p>\n<\/td>\n | \n MiniMed 780G insulin pump and Medtronic Extended infusion set<\/p>\n<\/td>\n | \n iLet ACE Pump<\/p>\n<\/td>\n<\/tr>\n | \n\n Algorithm targets<\/b><\/p>\n<\/td>\n | \n 110, 120, 130, 140 and 150 mg\/dL<\/p>\n<\/td>\n | \n 112.5\u2013160 mg\/dL<\/p>\n<\/td>\n | \n Referred to as correction range; range of 87\u2013180 mg\/dL in master branch; dev branch allows for lower and higher ranges<\/p>\n<\/td>\n | \n 120 mg\/dL<\/p>\n<\/td>\n | \n 120 mg\/dL<\/p>\n<\/td>\n | \n 100, 110 and 120 mg\/dL<\/p>\n<\/td>\n | \n 110, 120 and 130 mg\/dL<\/p>\n<\/td>\n<\/tr>\n | \n\n Temporary targets<\/b><\/p>\n<\/td>\n | \n Activity: 150 mg\/dL<\/p>\n<\/td>\n | \n Exercise: 140\u2013160 mg\/dL<\/p>\n Sleep: 112.5\u2013120 mg\/dL<\/p>\n<\/td>\n | \n Override: allows temporary target glucose changes as well as %change applied to basal\/bolus doses for a defined period (if room allows)<\/p>\n<\/td>\n | \n 150 mg\/dL<\/p>\n<\/td>\n | \n 150 mg\/dL<\/p>\n<\/td>\n | \n 150 mg\/dL<\/p>\n<\/td>\n | \n N\/A<\/p>\n<\/td>\n<\/tr>\n | \n\n Minimum daily insulin<\/b><\/p>\n<\/td>\n | \n 5 units<\/p>\n<\/td>\n | \n 10 units<\/p>\n<\/td>\n | \n No standard recommended minimum<\/p>\n<\/td>\n | \n 8 units<\/p>\n<\/td>\n | \n 8 units<\/p>\n<\/td>\n | \n 8 units<\/p>\n<\/td>\n | \n 8 units<\/p>\n<\/td>\n<\/tr>\n | \n\n Maximum fill<\/b><\/p>\n<\/td>\n | \n 200 units<\/p>\n<\/td>\n | \n 300 units (t:slim X2) or 200 units (Mobi)<\/p>\n<\/td>\n | \n Based on the pump in use<\/p>\n<\/td>\n | \n 300 units<\/p>\n<\/td>\n | \n 300 units<\/p>\n<\/td>\n | \n 300 units<\/p>\n<\/td>\n | \n 180 units<\/p>\n<\/td>\n<\/tr>\n | \n\n Basal increment<\/b><\/p>\n<\/td>\n | \n 0.05 units<\/p>\n<\/td>\n | \n 0.001 units<\/p>\n<\/td>\n | \n Based on the pump in use<\/p>\n<\/td>\n | \n 0.1, 0.05 or<\/p>\n 0.025 units<\/p>\n<\/td>\n | \n 0.1, 0.05 or<\/p>\n 0.025 units<\/p>\n<\/td>\n | \n 0.1, 0.05 or<\/p>\n 0.025 units<\/p>\n<\/td>\n | \n N\/A<\/p>\n<\/td>\n<\/tr>\n | \n\n Bolus increment<\/b><\/p>\n<\/td>\n | \n 0.05 units<\/p>\n<\/td>\n | \n 0.01 units<\/p>\n<\/td>\n | \n Based on the pump in use<\/p>\n<\/td>\n | \n 0.1, 0.05 or<\/p>\n 0.025 units<\/p>\n<\/td>\n | \n 0.1, 0.05 or<\/p>\n 0.025 units<\/p>\n<\/td>\n | \n 0.1, 0.05 or<\/p>\n 0.025 units<\/p>\n<\/td>\n | \n N\/A<\/p>\n<\/td>\n<\/tr>\n | \n\n Ability to override bolus<\/b><\/p>\n<\/td>\n | \n Yes<\/p>\n<\/td>\n | \n Yes<\/p>\n<\/td>\n | \n Yes<\/p>\n<\/td>\n | \n No<\/p>\n<\/td>\n | \n No<\/p>\n<\/td>\n | \n No<\/p>\n<\/td>\n | \n No<\/p>\n<\/td>\n<\/tr>\n | \n\n Extended bolus<\/b><\/p>\n<\/td>\n | \n No, manual mode only<\/p>\n<\/td>\n | \n Yes<\/p>\n<\/td>\n | \n No, but it can emulate an extended bolus based on carb absorption<\/p>\n<\/td>\n | \n No, manual mode only<\/p>\n<\/td>\n | \n No, manual mode only<\/p>\n<\/td>\n | \n No, manual mode only<\/p>\n<\/td>\n | \n No<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n | |