Continuous glucose monitoring in pregnant women with type 1 diabetes: an observational cohort study of 186 pregnancies

Glycemic control assessed by continuous glucose monitoring during pregnancy in women with type 1 diabetes and its association with preeclampsia, an observational Swedish cohort study

INTRODUCTION

Women with type 1 diabetes have an increased risk of preeclampsia (PE), but it is not fully understood if degree of glycemic control is associated with this risk. The aim of this study was to assess glycemic control during pregnancy analyzed by continuous glucose monitoring (CGM) in women with and without PE and to investigate if glycemic control is associated with increased risk of PE.

MATERIAL AND METHODS

A total of 120 pregnant Swedish women with type 1 diabetes using CGM were included. Background factors and pregnancy outcomes were collected from medical records. CGM data were collected via the internet-based platform Diasend. Mean glucose, standard deviation of mean glucose, percentage of time in target, time below target, and time above target were presented for each trimester in women who did or did not develop PE. Associations between CGM-derived metrics and PE were analyzed with logistic regression and adjusted for confounders.

RESULTS

Twenty-two women (18.3%) developed PE. There were no significant differences in maternal characteristics between women with and without PE. Glycemic control improved in each trimester but was suboptimal in both groups. Time in target increased from 59% in the non-PE group and 54% in the PE group in the first trimester to 65% in both groups in the third trimester. There were no significant associations between glycemic control and PE after adjustment for confounders.

CONCLUSIONS

Degree of glycemic control during pregnancy assessed by CGM was not associated with development of PE in women with type 1 diabetes. However, more research is needed to understand the role of glycemic control in relation to development of PE.

An automated insulin delivery system from pregestational care to postpartum in women with type 1 diabetes. Preliminary experience with telemedicine in 6 patients

INTRODUCTION

The use of most commercially available automated insulin delivery (AID) systems is off-label in pregnancy. However, an increasing number of women with type 1 diabetes (T1D) use such devices throughout pregnancy and delivery. We analysed the data of six women with T1D from a single centre (Diabetology Outpatient Clinic of District-63/Asl Salerno, Italy) who were able to start and maintain AID therapy with the MiniMed™ 780G (Medtronic, Minneapolis, MN, USA) throughout the pregestational care period, pregnancy, delivery, and postpartum.

METHODS

We retrospectively collected data from six patients with T1D who received training and initiation on use of the MiniMed™ 780G and attended follow-up visits throughout pregnancy (these visits were virtual because of the COVID-19 pandemic). All patients maintained their devices in the closed-loop setting throughout pregnancy and during labour and delivery. We analysed data from the pregestational phase to the first 30 days postpartum.

RESULTS

All patients achieved the recommended metabolic goals before conception [median time in range (TIR) of 88% for 70-180 mg/dL; median pregnancy-specific TIR 63-140 mg/dL (ps-TIR) of 66% and maintained the ps-TIR until delivery (median ps-TIR 83%). All patients had slightly better metrics during the night than during the day, with a very low time below range of < 63 mg/dL. Optimal glycaemic values were also maintained on the day of labour and delivery (median ps-TIR 92.5%) and in the first 30 days postpartum, with no severe hypoglycaemia. The only neonatal complications were jaundice in one child and an interatrial defect in another child.

CONCLUSION

In our well-selected and trained patients, use of the MiniMed™ 780G helped to achieve and maintain ps-metrics from the pregestational period to delivery despite the fact that the algorithm is not set to achieve the ambitious glycaemic values recommended for pregnancy.

Real-World Evidence of Off-Label Use of Commercially Automated Insulin Delivery Systems Compared to Multiple Daily Insulin Injections in Pregnancies Complicated by Type 1 Diabetes

Aims: To compare glycemic control and maternal-fetal outcomes of women with type 1 diabetes (T1D) using hybrid closed loop (HCL) versus multiple daily insulin injections (MDI) plus continuous glucose monitoring. Methods: Multicenter prospective cohort study of pregnant women with T1D in Spain. We evaluated HbA1c and time spent within (TIR), below (TBR), and above (TAR) the pregnancy-specific glucose range of 3.5-7.8 mmol/L. Adjusted models were performed for adverse pregnancy outcomes, including baseline maternal characteristics and center. Results: One hundred twelve women were included (HCL n = 59). Women in the HCL group had a longer duration of diabetes and higher rates of prepregnancy care. There was no between-group difference in HbA1c in any trimester. However, in the second trimester, MDI users had a greater decrease in HbA1c (-6.12 ± 9.06 vs. -2.16 ± 7.42 mmol/mol, P = 0.031). No difference in TIR (3.5-7.8 mmol/L) and TAR was observed between HCL and MDI users, but with a higher total insulin dose in the second trimester [+0.13 IU/kg·day)]. HCL therapy was associated with increased maternal weight gain during pregnancy (βadjusted = 3.20 kg, 95% confidence interval [CI] 0.90-5.50). Regarding neonatal outcomes, newborns of HCL users were more likely to have higher birthweight (βadjusted = 279.0 g, 95% CI 39.5-518.5) and macrosomia (ORadjusted = 3.18, 95% CI 1.05-9.67) compared to MDI users. These associations disappeared when maternal weight gain or third trimester HbA1c was included in the models. Conclusions: In a real-world setting, HCL users gained more weight during pregnancy and had larger newborns than MDI users, while achieving similar glycemic control in terms of HbA1c and TIR.

Association between extrapolated time in range and large for gestational age infants in pregnant women with type 1 diabetes

AIMS

To evaluate the association between extrapolated time in range (eTIR), measured by self-monitoring of blood glucose (SMBG), and large-for-gestational-age (LGA) infants in pregnancies with type 1 diabetes (T1D).

METHODS

Retrospective cohort analysis including singleton pregnancies with T1D who started antenatal care before 20 gestational weeks and delivered live newborns at a Brazilian hospital between 2010 and 2019, with LGA fetuses as the main outcome. Glycemic records acquired using SMBG were categorized as eTIR, extrapolated time below range (eTBR), and extrapolated time above range (eTAR). Women were divided into two groups (LGA and adequate for gestational age [AGA]) and compared regarding clinical characteristics, obstetric outcomes, and frequencies of eTIR, eTBR, and eTAR. Logistic regression analysis verified the independent predictive variables for LGA infants.

RESULTS

Data from 125 pregnancies were analyzed. For the first, second and third trimesters, each 1 % increase in eTIR was associated with a decreased risk of LGA by 2.9 % (OR: 0.971; 95%CI: 0.945-0.998), 2.5 % (OR: 0.975; 95%CI: 0.951-0.999) and 2.3 % (OR: 0.977; 95%CI: 0.955-0.998) and each 1 % increase in eTAR was associated with an increased risk of LGA by 2.7 % (OR: 1.027; 95%CI: 1.005-1.050), 3.9 % (OR: 1.039; 95%CI: 1.014-1.063) and 4.6 % (OR: 1.046; 95%CI: 1.018-1.075), respectively.

CONCLUSION

The concept of TIR can be extrapolated to patients undergoing SMBG to assess the risk of LGA infants in pregnant women with T1D.

Continuous Glucose Monitoring and Time in Range: Association with Adverse Outcomes among People with Type 2 or Gestational Diabetes Mellitus

OBJECTIVE

 Continuous glucose monitoring (CGM) has become available for women with type 2 diabetes mellitus (T2DM) or gestational diabetes mellitus (GDM) during pregnancy. The recommended time in range (TIR, blood glucose 70-140 mg/dL) and its correlation with adverse pregnancy outcomes in this group is unknown. Our aim was to compare maternal and neonatal outcomes in pregnant people with T2DM or GDM with average CGM TIR values >70 versus ≤70%.

STUDY DESIGN

 We conducted a retrospective cohort study of all individuals using CGM during pregnancy from January 2017 to June 2022. Individuals with type 1 diabetes mellitus, or those missing CGM or delivery data were excluded. Primary composite neonatal outcome included any of the following: large for gestational age, NICU admission, need for intravenous glucose, respiratory support, or neonatal death. Secondary outcomes included other maternal and neonatal outcomes. Regression models were used to estimate adjusted odds ratio (aOR) and 95% confidence interval (CI).

RESULTS

 During the study period, 141 individuals with diabetes utilized CGM during pregnancy, with 65 (46%) meeting inclusion criteria. Of the study population, 28 (43%) had TIR ≤70% and 37 (57%) had TIR > 70%. Compared with those with TIR > 70%, the primary composite outcome occurred more frequently in neonates of individuals TIR ≤70% (71.4 vs. 37.8%, aOR: 4.8, 95% CI: 1.6, 15.7). Furthermore, individuals with TIR ≤70% were more likely to have hypertensive disorders (42.9 vs. 16.2%, OR: 3.9, 95% CI: 1.3, 13.0), preterm delivery (54 vs. 27%, OR: 3.1, 95% CI: 1.1, 9.1): , and cesarean delivery (96.4 vs. 51.4%, OR: 4.6, 95% CI: 2.2, 15.1) compared with those with TIR >70%.

CONCLUSION

 Among people with T2DM or GDM who utilized CGM during pregnancy, 4 out 10 individuals had TIR ≤70% and, compared with those with TIR > 70%, they had a higher likelihood of adverse neonatal and maternal outcomes.

KEY POINTS

· Time in range can be utilized as a metric for pregnant patients using continuous glucose monitor.. · Time in range >70% is achievable by 6 out of 10 patients.. · Time in range below goal is associated with adverse neonatal and maternal outcomes..

Mean Glucose and Gestational Weight Gain as Predictors of Large-for-Gestational-Age Infants in Pregnant Women with Type 1 Diabetes Using Continuous Glucose Monitoring

Aims/hypothesis: To compare glycemic metrics during pregnancy between women with type 1 diabetes (T1D) delivering large-for-gestational-age (LGA) and appropriate-for-gestational-age (AGA) infants, and to identify predictors of LGA infants. Materials and Methods: A cohort study including 111 women with T1D using intermittently scanned continuous glucose monitoring from conception until delivery. Average sensor-derived metrics: mean glucose, time in range in pregnancy (TIRp), time above range in pregnancy, time below range in pregnancy, and coefficient of variation throughout pregnancy and in pregnancy intervals of 0-10, 11-21, 22-33, and 34-37 weeks were compared between women delivering LGA and AGA infants. Predictors of LGA infants were sought for. Infant growth was followed until 3 months postdelivery. Results: In total, 53% (n = 59) delivered LGA infants. Mean glucose decreased during pregnancy in both groups, with women delivering LGA infants having a 0.4 mmol/L higher mean glucose from 11-33 weeks (P = 0.01) compared with women delivering AGA infants. Mean TIRp >70% was obtained from 34 weeks in women delivering LGA infants and from 22-33 weeks in women delivering AGA infants. Independent predictors for delivering LGA infants were mean glucose throughout pregnancy and gestational weight gain. At 3 months postdelivery, infant weight was higher in infants born LGA compared with infants born AGA (6360 g ± 784 and 5988 ± 894, P = 0.04). Conclusions/interpretations: Women with T1D delivering LGA infants achieved glycemic targets later than women delivering AGA infants. Mean glucose and gestational weight gain were independent predictors for delivering LGA infants. Infants born LGA remained larger postdelivery compared with infants born AGA.

Continuous Glucose Monitoring Metrics for Pregnancies Complicated by Diabetes: Critical Appraisal of Current Evidence

Ascertaining the utility of continuous glucose monitoring (CGM) in pregnancy complicated by diabetes is a rapidly evolving area, as the prevalence of type 1 diabetes (T1D), type 2 diabetes (T2D), and gestational diabetes mellitus (GDM) escalates. The seminal randomized controlled trial (RCT) evaluating CGM use added to standard care in pregnancy in T1D demonstrated significant improvements in maternal glycemia and neonatal health outcomes. Current clinical guidance recommends targets for percentage time in range (TIR), time above range (TAR), and time below range (TBR) during pregnancy complicated by T1D that are widely used in clinical practice. However, the superiority of CGM over blood glucose monitoring (BGM) is still questioned in both T2D and GDM, and whether glucose targets should be different than in T1D is unknown. Questions requiring additional research include which CGM metrics are superior in predicting clinical outcomes, how should pregnancy-specific CGM targets be defined, whether CGM targets should differ according to gestational age, and if CGM metrics during pregnancy should be similar across all types of diabetes. Limiting the potential for CGM to improve pregnancy outcomes may be our inability to maintain TIR > 70% throughout gestation, a goal achieved in the minority of patients studied. Adverse pregnancy outcomes remain high in women with T1D and T2D in pregnancy despite CGM technology, and this review explores the potential reasons and questions yet to be investigated.

Clinical Effectiveness of Continuous Glucose Monitoring in Pregnancies Affected by Type 1 Diabetes

Background: Continuous glucose monitoring (CGM) improves neonatal outcomes in type 1 diabetes pregnancies; however, its effectiveness has not been assessed in a real-world setting in the United States. Objective: The Triple C Study aimed to examine the clinical effectiveness, assessed through maternal glucose control and gestational health outcomes, of CGM use compared with self-monitoring of blood glucose (SMBG) in pregnancies associated with type 1 diabetes in a real-world setting. Research Design and Methods: We retrospectively identified 160 type 1 diabetes pregnancies at the Barbara Davis Center for Diabetes managed with CGM therapy (n = 109) or SMBG (n = 51) over a 6.5-year period (2014-2020). Obstetric care was provided at multiple practices. CGM use was defined as ≥60% wear in the second and third trimesters of pregnancy. Data were obtained from the electronic medical record system, hospital records, and vital statistics departments (Colorado and Wyoming). We used Student's t-test for continuous variables and chi-square test for categorical variables to compare outcomes between groups. Results: The CGM group had more participants meeting trimester-specific hemoglobin A1C (HbA1c) goals throughout pregnancy and postpartum (P < 0.01 in each time period). The CGM group had fewer participants never meeting HbA1c goals in any trimester than the SMBG group (P < 0.001). There were no significant differences in neonatal outcomes between groups, other than for macrosomia (12.8% CGM vs. 29.4% SMBG, P = 0.01). Infants of CGM users required a neonatal intensive care unit admission less often (52.9% CGM vs. 68.3% SMBG, P = 0.0989). Conclusions: CGM use was associated with improved maternal glucose levels in a diverse real-world cohort.

Continuous glucose monitoring metrics in pregnancy with type 1 diabetes mellitus

Managing diabetes during pregnancy is challenging, given the significant risk it poses for both maternal and foetal health outcomes. While traditional methods involve capillary self-monitoring of blood glucose level monitoring and periodic HbA1c tests, the advent of continuous glucose monitoring (CGM) systems has revolutionized the approach. These devices offer a safe and reliable means of tracking glucose levels in real-time, benefiting both women with diabetes during pregnancy and the healthcare providers. Moreover, CGM systems have shown a low rate of side effects and high feasibility when used in pregnancies complicated by diabetes, especially when paired with continuous subcutaneous insulin infusion pump as hybrid closed loop device. Such a combined approach has been demonstrated to improve overall blood sugar control, lessen the occurrence of preeclampsia and neonatal hypoglycaemia, and minimize the duration of neonatal intensive care unit stays. This paper aims to offer a comprehensive evaluation of CGM metrics specifically tailored for pregnancies impacted by type 1 diabetes mellitus.

Use of Advanced Hybrid Closed-Loop System during Pregnancy: Strengths and Limitations of Achieving a Tight Glycemic Control

Background: Pregnant women with type 1 diabetes mellitus (T1DM) face an elevated risk of complications for both themselves and their newborns. Experts recommend strict glycemic control. The advanced hybrid closed-loop (AHCL) system, though not officially approved for pregnant T1DM patients, is promising for optimal glycemic control. Methods: We collected CGM metrics, HbA1c levels, insulin pump settings, and doses from a 33-year-old pregnant woman with 23-year history of T1DM from the 6th week of gestation to birth. She was initially on continuous insulin pump therapy with CGM and switched to the AHCL system (MiniMedTM 780G, Medtronic, Northridge, CA, USA) between weeks 13 and 14. Results: The AHCL system improved glycemic control from weeks 14 to 26, achieving international guidelines with TIR = 72%, TAR = 24%, TBR = 4%. At week 30, TIR was 66%, TAR 31%. By altering diet and adding 'fake carbohydrates', she maintained TIR ≥ 70%, TBR ≤ 4%, TAR ≤ 26% from week 34 to birth. A healthy 4 kg, 53 cm baby boy was born at week 38. Conclusions: The use of the AHCL system holds significant promise for improving glycemic control in pregnancy. Optimal glycemic control with MiniMedTM 780G in pregnancy requires accurate carbohydrate counting, specific timing of insulin doses in relation to meal consumption and dietary choices that reduce the glycemic load of meals continue to be crucial factors in achieving optimal glycemic control during pregnancy using the MiniMedTM 780G system. Further research and clinical studies are needed to explore the full potential of these advanced systems in managing T1DM during pregnancy and optimizing maternal and neonatal outcomes.

A review of CONCEPTT study findings including subanalyses in pregnant women using continuous glucose monitoring with type 1 diabetes and their offspring

The main objective of this article is to provide a comprehensive review of continuous glucose monitor (CGM) use in pregnant women with type 1 diabetes (T1D) from the CONCEPTT study including subanalyses. Literature search was accessed through MEDLINE (1966-September 2023) using the key terms: CONCEPTT, pregnancy, women, T1D, and CGM with limitations set to distinguish human subjects written in English. A total of 17 publications including one main clinical trial and 15 subanalyses have been published to date regarding the use of CGM in pregnant women with T1D which were conducted by a research group identified as the CONCEPTT Collaborative Group. While advances in maternal care have resulted in safer pregnancy for both the mother and child, women with preexisting T1D and pregnancy still experience higher rates of complications both in the short and long term. The use of CGM in pregnancy has not been studied extensively until more recently. The CONCEPTT clinical trial was a landmark study that involved several subanalyses. The main trial proved that CGM use in T1D pregnancy resulted in less hyperglycemia in the third trimester, reduced large for gestational age (LGA, >90th percentile), reduced neonatal intensive care unit admissions lasting longer than 24 h, and reduced neonatal hypoglycemia. Although subanalyses showed a variety of results including 'inconclusive' due to lack of prespecification, it is believed that CGM in T1D during pregnancy is to be recommended and used for overall improved outcomes.

Effect of artificial pancreas system use on glycaemic control among pregnant women with type 1 diabetes mellitus: A meta-analysis of randomized controlled trials

AIM

To assess the efficacy of artificial pancreas systems (APS) use among pregnant women with type 1 diabetes mellitus (T1DM) by conducting a meta-analysis.

METHODS

We searched five databases, including EMBASE, Web of Science, PubMed, Cochrane Library and SCOPUS, for literature on APS use among pregnant women with T1DM before October 9, 2023. The primary endpoint was 24-hour time in range (TIR; 3.5-7.8 mmol/L). Secondary endpoints included glycaemic metrics for 24-hour (mean blood glucose [MBG], time above range [TAR], time below range [TBR]), and overnight TIR and TBR.

RESULTS

We identified four randomized controlled trials involving 164 participants; one study with 16 participants focused on overnight APS use, and the other three focused on 24-hour APS use. Compared with standard care, APS exhibited a favourable effect on 24-hour TIR (standard mean difference [SMD] = 0.53, 95% confidence interval [CI] 0.25, 0.80, P < 0.001), overnight TIR (SMD = 0.67, 95% CI 0.39, 0.95, P < 0.001), and overnight TBR (<3.5 mmol/L; SMD = -0.49, 95% CI -0.77, -0.21 P < 0.001), while there was no significant difference in 24-hour TAR, 24-hour TBR, or MBG between the two groups. We further conducted subgroup analyses after removing the trial focused on overnight APS use and showed that 24-hour APS use reduced not only the 24-hour TIR (SMD = 0.41, 95% CI 0.12, 0.71; P = 0.007) but also the 24-hour TBR (<2.8 mmol/L; SMD = -0.77, 95% CI -1.32, -0.23, P = 0.006).

CONCLUSION

Our findings suggest that APS might improve 24-hour TIR and overnight glycaemic control, and 24-hour APS use also significantly reduced 24-hour TBR (2.8 mmol/L) among pregnant women with T1DM.

Continuous Glucose Monitoring in Pregnancy

Diabetes mellitus in pregnancy is associated with adverse maternal and neonatal outcomes. Optimal glycemic control is associated with improved outcomes. Continuous glucose monitoring is a less invasive alternative to blood glucose measurements. Two types of continuous glucose monitoring are available in the market: real time and intermittently scanned. Continuous glucose monitoring is gaining popularity and is now recommended by some societies for glucose monitoring in pregnant women. In this review, we discuss the differences between the two types of continuous glucose monitoring, optimal treatment goals, and whether there is an improvement in maternal or neonatal outcomes.

Continuous glucose monitoring in pregnancies with type 1 diabetes: small increases in time-in-range improve maternal and perinatal outcomes

BACKGROUND

Continuous glucose monitors provide detailed information regarding glycemic control in pregnant patients with type 1 diabetes. Little data have been published examining the association between continuous glucose monitor parameters and perinatal outcomes among gravidas with type 1 diabetes using continuous glucose monitors.

OBJECTIVE

This study aimed to examine the association between perinatal outcomes and time-in-range as assessed by continuous glucose monitors used in pregnant individuals with type 1 diabetes. We hypothesized that higher time-in-range would be associated with lower risk of adverse perinatal outcomes.

STUDY DESIGN

This multicenter retrospective cohort study included all gravidas with type 1 diabetes using continuous glucose monitors who delivered from 2020 to 2022 at 5 University of California sites. Only those with continuous glucose monitor target range set to 70 to 140 mg/dL (±10 mg/dL) were included. Time-in-range (%) was recorded at 12, 16, 20, 24, 28, and 32 weeks. The primary maternal and neonatal outcomes were preeclampsia and large for gestational age, defined as birthweight ≥95th percentile. Kruskal-Wallis tests were used to compare median time-in-range between those with and without the primary outcomes. Log-binomial regression was used to obtain risk ratios, with adjustment for microvascular disease and years with type 1 diabetes.

RESULTS

A total of 91 patients were included. Most used an insulin pump (81%) and did not have diabetic microvascular disease (72%). Median time since diagnosis of type 1 diabetes was 16 years, and median periconception hemoglobin A1c was 6.7%. Compared with those with preeclampsia, normotensive gravidas had significantly higher time-in-range at nearly every time point. A similar pattern was observed for those with normal-birthweight infants compared with large-for-gestational-age infants. On adjusted analyses, every 5-unit increase in time-in-range at 12 weeks was associated with 45% and 46% reductions in the risks of preeclampsia and large for gestational age, respectively (preeclampsia: adjusted risk ratio, 0.55; 95% confidence interval, 0.30-0.99; large for gestational age: adjusted risk ratio, 0.54; 95% confidence interval, 0.29-0.99).

CONCLUSION

Higher time-in-range is associated with lower risk of preeclampsia and large for gestational age. This association is observed early in gestation, when each 5-unit increase in time-in-range is associated with ∼50% reduction in the risk of these complications. These findings can be used to counsel patients regarding the risk of pregnancy complications at specific time-in-range values, and to encourage patients that even small improvements in time-in-range can have significant impact on pregnancy outcomes. Larger studies are needed to further explore these findings and to identify optimal time-in-range to reduce perinatal complication rates.

Automated Insulin Delivery for Pregnant Women With Type 1 Diabetes: Where do we stand?

Automated insulin delivery (AID) systems mimic an artificial pancreas via a predictive algorithm integrated with continuous glucose monitoring (CGM) and an insulin pump, thereby providing AID. Outside of pregnancy, AID has led to a paradigm shift in the management of people with type 1 diabetes (T1D), leading to improvements in glycemic control with lower risk for hypoglycemia and improved quality of life. As the use of AID in clinical practice is increasing, the number of women of reproductive age becoming pregnant while using AID is also expected to increase. The requirement for lower glucose targets than outside of pregnancy and for frequent adjustments of insulin doses during pregnancy may impact the effectiveness and safety of AID when using algorithms for non-pregnant populations with T1D. Currently, the CamAPS® FX is the only AID approved for use in pregnancy. A recent randomized controlled trial (RCT) with CamAPS® FX demonstrated a 10% increase in time in range in a pregnant population with T1D and a baseline glycated hemoglobin (HbA1c) ≥ 48 mmol/mol (6.5%). Off-label use of AID not approved for pregnancy are currently also being evaluated in ongoing RCTs. More evidence is needed on the impact of AID on maternal and neonatal outcomes. We review the current evidence on the use of AID in pregnancy and provide an overview of the completed and ongoing RCTs evaluating AID in pregnancy. In addition, we discuss the advantages and challenges of the use of current AID in pregnancy and future directions for research.

Association of Continuous Glucose Monitoring Metrics With Pregnancy Outcomes in Patients With Preexisting Diabetes

OBJECTIVE

Continuous glucose monitoring (CGM) improves maternal glycemic control and neonatal outcomes in type 1 diabetes pregnancies compared with self-monitoring of blood glucose. However, CGM targets for pregnancy are based on expert opinion. We aimed to evaluate the association between CGM metrics and perinatal outcomes and identify evidence-based targets to reduce morbidity.

RESEARCH DESIGN AND METHODS

This was a retrospective cohort study of pregnant patients with type 1 or 2 diabetes who used real-time CGM and delivered at a U.S. tertiary center (2018-2021). Multiple gestations, fetal anomalies, and early pregnancy loss were excluded. Exposures included time in range (TIR; 65-140 mg/dL), time above range (TAR), time below range (TBR), glucose variability, average glucose, and glucose management indicator. The primary outcome was a composite of fetal or neonatal mortality, large or small for gestational age at birth, neonatal intensive care unit admission, hypoglycemia, shoulder dystocia or birth trauma, and hyperbilirubinemia. Logistic regression estimated the association between CGM metrics and outcomes, and optimal TIR was calculated.

RESULTS

Of 117 patients, 16 (13.7%) used CGM before pregnancy and 68 (58.1%) had type 1 diabetes. Overall, 98 patients (83.8%) developed the composite neonatal outcome. All CGM metrics, except TBR, were associated with neonatal morbidity. For each 5 percentage-point increase in TIR, there was 28% reduced odds of neonatal morbidity (odds ratio 0.72, 95% CI 0.58-0.89). The statistically optimal TIR was 66-71%.

CONCLUSIONS

Nearly all CGM metrics were associated with adverse neonatal morbidity and mortality and may aid management of preexisting diabetes in pregnancy. Our findings support the American Diabetes Association recommendation of 70% TIR.

7. Diabetes Technology: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Effects of continuous glucose monitoring on glycaemic control in type 2 diabetes: A systematic review and network meta-analysis of randomized controlled trials

AIMS

The aim of this study was to assess the efficacy of continuous glucose monitoring (CGM) versus self-monitoring of blood glucose (SMBG) in maintaining glycaemic control among people with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

The protocol was registered in PROSPERO (CRD42023387583). PubMed, Web of Science, EMBASE and OVID databases were searched from 1 January 2000 until 31 December 2022 for randomized controlled trials comparing CGM with SMBG in glycaemic control among the outpatients with T2DM. The primary endpoint was glycated haemoglobin, while the secondary endpoints included time in range, time below range and time above range. Both traditional and network meta-analyses were conducted to explore the efficacy of CGM on glycaemic control in T2DM.

RESULTS

Eleven high-quality studies, involving 1425 individuals with T2DM, were identified. Traditional meta-analysis revealed that CGM exhibited a significantly decreased [mean difference (MD): -0.31, 95% confidence interval (CI) (-0.45, -0.18)], time above range [MD: -9.06%, 95% CI (-16.00, -2.11)], time below range [MD: -0.30%, 95% CI (-0.49, -0.12)] and a significantly increased time in range [MD: 8.49%, 95% CI (3.96, 13.02)] compared with SMBG. The network meta-analysis showed that real-time CGM can improve the glycaemic control of patients with T2DM to the most extent.

CONCLUSIONS

CGM could provide T2DM with greater benefits in glycaemic management compared with SMBG, particularly in patients using real-time CGM. These findings provide an updated perspective on previous research and offer guidance for CGM use in T2DM.

15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Functional analysis of daily glycemic profiles and excessive fetal growth in pregnant patients with well-controlled type 1 diabetes: Retrospective cohort

AIMS

The study objective was to compare daily glycemic profiles throughout gestation between the mothers of large-for-gestational-age (LGA) and non-LGA newborns in patients with type 1 diabetes (T1D).

METHODS

We selected 102 eligible pregnant women who were treated with sensor-augmented pumps in our single-center retrospective cohort study. We used functional data analysis to compare glycemic control across gestation.

RESULTS

Median HbA1c values in the first, second, and third trimester were 6.23 %, 5.49 %, and 5.75 % respectively. Median time-in-range (TIR) exceeded 70 % in each trimester (72.4 %, 72.5 %, and 75.9 %, respectively). From 59 % up to 77 % of women met the criteria for well-controlled T1D defined by the mean HbA1c and TIR in each trimester. Despite that, 27 % (28/102) of pregnancies were complicated by LGA. Mothers of LGA infants had significantly increased HbA1c levels and decreased TIR values in the second and third trimesters. The most significant differences in daily mean glucose values between LGA and non-LGA newborns' mothers occurred between 26 and 32 weeks of pregnancy. These discrepancies were noted in daytime glucose values rather than nocturnal and fasting glucose levels.

CONCLUSIONS

Mothers of LGA newborns present significantly worse glycemic control. Our findings may emphasize the need for more rigorous daytime glycemic control.

Continuous Glucose Monitoring Metrics in High-Risk Pregnant Women with Type 2 Diabetes

Objective: To describe glucose metrics in a high-risk population of women with type 2 diabetes (T2DM) in pregnancy and to explore the associations with neonatal outcomes. Research Design and Methods: Prospective observational study of 57 women. Continuous glucose monitoring (CGM) trajectories were determined from metrics collected in early and late gestation using the first and last two (mean 16 and 35) weeks of Freestyle Libre data. Logistic regression was used to examine associations of CGM metrics with neonatal hypoglycemia (glucose <2.6 mmol/L requiring intravenous dextrose) and large for gestational age (LGA) (>90th percentile for gestational age and sex). Pregnancy-specific target glucose range was 3.5-7.8 mmol/L (63-140 mg/dL). Results: Forty-one women used CGM for 15 weeks (mean age 33 years, 73% Aboriginal or Torres Strait Islander, 32% living remotely). There was limited change in average metrics from early to late pregnancy. For the subgroup with sensor use >50% (n = 29), mean time in range (TIR) increased by 9%, time above range reduced by 12%, average glucose reduced by 1 mmol/L, and time below range increased by 3%. Neonatal hypoglycemia was associated with most CGM metrics, HbA1c and CGM targets, particularly those from late pregnancy. LGA was associated with hyperglycemic metrics from early pregnancy. Each 1% increase TIR was associated with a 4%-5% reduction in risk of neonatal complications. Conclusion: In this high-risk group of women with T2DM, CGM metrics only improved during pregnancy in those with greater sensor use and were associated with LGA in early pregnancy and neonatal hypoglycemia throughout. Culturally appropriate health care strategies are critical for successful use of CGM technology.

Continuous glucose monitoring metrics and pregnancy outcomes in insulin-treated diabetes: A post-hoc analysis of the GlucoMOMS trial

AIM

To investigate the association between continuous glucose monitoring (CGM) metrics and perinatal outcomes in insulin-treated diabetes mellitus in pregnancy.

MATERIALS AND METHODS

In a post-hoc analysis of the GlucoMOMS randomized controlled trial, we investigated the association between the metrics of an offline, intermittent CGM, glycated haemoglobin (HbA1c) and perinatal outcomes per trimester in different types of diabetes (type 1, 2 or insulin-treated gestational diabetes mellitus [GDM]). Data were analysed using multivariable binary logistic regression. Outcomes of interest were neonatal hypoglycaemia, pre-eclampsia, preterm birth, large for gestational age (LGA) and Neonatal Intensive Care Unit (NICU) admission. The glucose target range was defined as 3.5-7.8 mmol/L (63-140 mg/dL).

RESULTS

Of the 147 participants (N = 50 type 1 diabetes, N = 94 type 2 diabetes/insulin-treated GDM) randomized to the CGM group of the GlucoMOMS trial, 115 participants had CGM metrics available and were included in the current study. We found that, in pregnancies with type 1 diabetes, a higher second trimester mean glucose was associated with LGA (odds ratio 2.6 [95% confidence interval 1.1-6.2]). In type 2 and insulin-treated gestational diabetes, an increased area under the curve above limit was associated with LGA (odds ratio 10.0 [95% confidence interval 1.4-72.8]). None of the CGM metrics were associated with neonatal hypoglycaemia, pre-eclampsia, shoulder dystocia, preterm birth and NICU admission rates for pregnancies complicated by any type of diabetes.

CONCLUSION

In this study, in type 2 diabetes or insulin-treated GDM, the glucose increased area under the curve above limit was associated with increased LGA. In type 1 diabetes, the mean glucose was the major determinant of LGA. Our study found no evidence that other CGM metrics determined adverse pregnancy outcomes.

Maternal and fetal outcomes in a retrospective cohort of obstetrical patients that used an insulin pump paired with a continuous glucose monitor

OBJECTIVE

To assess maternal and neonatal outcomes in pregnant pregestational diabetic patients using a continuous subcutaneous insulin infusion (CSII) pump paired with a continuous glucose monitor (CGM).

METHODS

This retrospective cohort study included 55 patients who delivered within one healthcare system from October 2019 to October 2022 with pregestational diabetes managed using CSII pumps paired with CGM. Maternal blood glucose (BG) data were analyzed for the two-week period preceding delivery. The percentage of time spent at a BG level of less than 140 mg/dL was recorded and compared between patients with and without obstetric and neonatal morbidities.

RESULTS

Patients who delivered with severe preeclampsia (S. PreE) had a significantly lower mean percentage of time spent at BG < 140 mg/dL than those who did not (S. PreE 15/55, 63.1% ± 19.0 vs. 40/55, 73.6% ± 13.8; p = 0.03). Mothers who had a preterm birth (PTB) had a significantly lower mean percentage of time spent at BG < 140 mg/dL than those who delivered at term (PTB 35/55, 66.4% ± 16.4 vs 20/55, 78.3% ± 11.9; p = 0.006). The mean percentage of time spent at a BG < 140 mg/dL among mothers of neonates with respiratory distress syndrome (RDS) was significantly lower than those without RDS (RDS present 13/55, 59.7% ± 20.4 vs 42/55, 74.1% ± 12.7; p = 0.003). There was a significant correlation between a greater neonatal birth weight percentile and worse time spent at BG < 140 mg/dL (r = - 0.31; p = 0.02). No other significant differences were observed between the groups.

CONCLUSION

Improved blood glucose levels in pregestational diabetic patients using a CSII pump and CGM is associated with reduced maternal and neonatal morbidity as well as lower birth weight percentile neonates. Future studies are needed to clarify how much time each day a patient needs to spend below a given blood sugar, how long this blood glucose should be maintained, and what specific blood glucose target should be selected.

MiniMedTM 780G Advanced Hybrid Closed-Loop System Study in Pregnant Women with Type 1 Diabetes

Background: Evaluate the impact of the MiniMed™ 780G advanced hybrid closed-loop (AHCL) system on the glucose profile of pregnant women with type 1 diabetes (T1D) and maternal-neonatal complications. Methods: From April 2021 to September 2022, pregnant women with T1D treated with the AHCL system were included in an observational multicenter retrospective study. Continuous glucose monitoring parameters were analyzed monthly during pregnancy as well as maternal-neonatal complications. Results: Thirteen pregnant women, including a twin pregnancy (age: 33 ± 3 years, hemoglobin A1c [HbA1c]: 7.3% ± 0.7%, insulin doses: 0.72 ± 0.21 U/kg/day) were analyzed. At delivery, gestational age was 37 ± 2 weeks. During first 2 weeks of pregnancy, time in range (TIR, 63-140 mg/dL) was 46% (34-55) and increased to 54% (51-59) (P < 0.01), 64% (48-68) (P < 0.01), and 66% (60-70) (P < 0.001) during the first, second, and third trimester, respectively. During the night, TIR (63-140 mg/dL) was >70% throughout pregnancy. Time below the range <63 mg/dL increased from 0.5% (0-2) to 1.3% (0.7-2.2), 2% (1.2-3.5) (P < 0.05), and 1.3% (1.31-3) (P < 0.05) during the first, second, and third trimester, respectively. At delivery, insulin doses increased to 0.89 ± 0.35 IU/kg/day (P < 0.01), and HbA1c decreased to 6.4% ± 0.6% (P = 0.005). The reported carbohydrate amount increased from 167 ± 363 g/d during early pregnancy to 243 ± 106 g/d (P < 0.01) at delivery. The birthweight was 3134 ± 711 g, with 5/14 macrosomia and 2/14 neonatal hypoglycemia. Moreover, 5/13 patients had a preeclampsia and 9/13 a cesarean section, including three cases of scarred uterus. The Clinical Trial Registration number is: CE-2022-55. Conclusion: The AHCL system provided good glucose control during pregnancy and recommendation targets were reached during the nocturnal period only. The maternal and neonatal complications remained high.

Roadmap to the Effective Use of Continuous Glucose Monitoring in Pregnancy

The landscape for managing type 1 diabetes during pregnancy has been transformed by increasing use of continuous glucose monitoring (CGM). Women are aiming for pregnancy-specific glucose targets or 70% time in range for pregnancy (TIRp; 63-140 mg/dL) as soon as possible, knowing that every extra 5% TIRp has benefits for reducing the risks of complications in their babies. Ongoing monitoring of maternal A1C (at pregnancy confirmation and at 20, 28, and 36 weeks' gestation) remains useful. Intensification of glycemic management and instruction in using CGM (if not already used) is recommended for individuals with an A1C >6.0% after 20 weeks. A better understanding of CGM-documented glycemic changes throughout pregnancy is needed to inform future management of gestational diabetes and pregnancy in people with type 2 diabetes. Research regarding overcoming barriers to CGM use and optimal TIRp targets for pregnant individuals with type 2 diabetes from diverse racial/ethnic groups is urgently needed.

Advances in diabetes management: have pregnancy outcomes in women with type 1 diabetes changed in the last decades?

AIMS

Over the recent years multiple therapeutic and management opportunities have been made available to treat pregnant women with Type 1 diabetes (T1DM). However, analyses assessing whether these different approaches may have any specific advantage/disadvantage in metabolic control and neonatal outcomes is still limited. The aim of this study was to compare metabolic control and neonatal outcomes in pregnant women with T1DM among different basal insulins (NPH vs. analogue), insulin administration ways [Multiple Daily Injections (MDI) vs. Continuous Subcutaneous Insulin Infusion (CSII)] and glucose monitoring systems [Self-Monitoring of Blood Glucose (SMBG) vs. real-time/intermittently scanned Continuous Glucose Monitoring (rtCGM/isCGM)].

METHODS

A retrospective analysis on metabolic data and neonatal outcomes of 136 T1DM pregnant women (76% on MDI, based on NPH (51%) or analogue (49%); 24% on CSII; 24% using rtCGM/isCGM), managed between 2008 and 2020, was performed, comparing different therapeutic approaches.

RESULTS

Metabolic data and neonatal outcomes were comparable among women treated with different basal insulins. Women on CSII planned their pregnancy more frequently (82 vs. 60%; p = 0.043) and had better pregestational HbA1c (52 ± 5 vs. 60 ± 13 mmol/mol; p = 0.044) and first trimester HbA1c (48 ± 4 vs. 51 ± 8 mmol/mol; p = 0.047). Pregestational and first trimester HbA1c were also lower in women using rtCGM/isCGM (53 ± 8 vs. 58 ± 13 mmol/mol; p = 0.027 and 46 ± 5 vs. 51 ± 7 mmol/mol; p = 0.034, respectively). In the whole cohort, LGA risk was directly correlated to HbA1c at third trimester (correlation coefficient: 0.335, p = 0.001) and inversely correlated to the achievement of HbA1c target (≤6% [<42 mmol/mol]) at third trimester (correlation coefficient: - 0.367, p < 0.001).

CONCLUSION

Treatment with insulin analogs didn't significantly change metabolic control and neonatal outcomes in T1DM women, while CSII and rtCGM/isCGM can optimize preconception and first trimester pregnancy glycemic control. Irrespective of the therapeutic management, third trimester HbA1c remains the strongest risk factor for LGA.

The Benefits Of Continuous Glucose Monitoring In Pregnancy

Previous studies have consistently demonstrated the positive effects of continuous glucose monitoring (CGM) on glycemic outcomes and complications of diabetes in people with type 1 diabetes. Guidelines now consider CGM to be an essential and cost-effective device for managing type 1 diabetes. As a result, insurance coverage for it is available. Evidence supporting CGM continues to grow and expand to broader populations, such as pregnant people with type 1 diabetes, people with type 2 diabetes treated only with basal insulin therapy, and even type 2 diabetes that does not require insulin treatment. However, despite the significant risk of hyperglycemia in pregnancy, which leads to complications in more than half of affected newborns, CGM indications and insurance coverage for those patients are unresolved. In this review article, we discuss the latest evidence for using CGM to offer glycemic control and reduce perinatal complications, along with its cost-effectiveness in pregestational type 1 and type 2 diabetes and gestational diabetes mellitus. In addition, we discuss future prospects for CGM coverage and indications based on this evidence.

Continuous glucose monitoring-derived glycemic metrics and adverse pregnancy outcomes among women with gestational diabetes: a prospective cohort study

Background

Continuous glucose monitoring (CGM) has shown potential in improving maternal and neonatal outcomes in individuals with type 1/2 diabetes, but data in gestational diabetes mellitus (GDM) is limited. We aimed to explore the relationship between CGM-derived metrics during pregnancy and pregnancy outcomes among women with GDM.

Methods

We recruited 1302 pregnant women with GDM at a mean gestational age of 26.0 weeks and followed them until delivery. Participants underwent a 14-day CGM measurement upon recruitment. The primary outcome was any adverse pregnancy outcome, defined as having at least one of the outcomes: preterm birth, large-for-gestational-age (LGA) birth, fetal distress, premature rupture of membranes, and neonatal intensive care unit (NICU) admission. The individual outcomes included in the primary outcome were considered as secondary outcomes. We conducted multivariable logistic regression to evaluate the association of CGM-derived metrics with these outcomes.

Findings

Per 1-SD difference in time above range (TAR), glucose area under the curve (AUC), nighttime mean blood glucose (MBG), daytime MBG, and daily MBG was associated with higher risk of any adverse pregnancy outcome, with odds ratio: 1.22 (95% CI 1.08-1.36), 1.22 (95% CI 1.09-1.37), 1.18 (95% CI 1.05-1.32), 1.21 (95% CI 1.07-1.35), and 1.22 (95% CI 1.09-1.37), respectively. Time in range, TAR, AUC, nighttime MBG, daytime MBG, daily MBG, and mean amplitude of glucose excursions were positively associated, while time blow range was inversely associated with the risk of LGA. Additionally, higher value for TAR was associated with higher risk of NICU admission. We further summarized the potential thresholds of TAR (2.5%) and daily MBG (4.8 mmol/L) to distinguish individuals with and without any adverse pregnancy outcome.

Interpretation

The CGM-derived metrics may help identify individuals at higher risk of adverse pregnancy outcomes. These CGM biomarkers could serve as potential new intervention targets to maintain a healthy pregnancy status among women with GDM.

Funding

National Key R&D Program of China, National Natural Science Foundation of China, and Westlake Laboratory of Life Sciences and Biomedicine.

Expert Recommendations for Using Time-in-Range and Other Continuous Glucose Monitoring Metrics to Achieve Patient-Centered Glycemic Control in People With Diabetes

New metrics for assessing glycemic control beyond HbA1c have recently emerged due to the increasing use of continuous glucose monitoring (CGM) in diabetes clinical practice. Among them, time in range (TIR) has appeared as a simple and intuitive metric that correlates inversely with HbA1c and has also been newly linked to the risk of long-term diabetes complications. The International Consensus on Time in Range established a series of target glucose ranges (TIR, time below range and time above range) and recommendations for time spent within these ranges for different diabetes populations. These parameters should be evaluated together with the ambulatory glucose profile (AGP). Using standardized visual reporting may help people with diabetes and healthcare professionals in the evaluation of glucose control in frequent clinical situations. The objective of the present review is to provide practical insights to quick interpretation of patient-centered metrics based on flash glucose monitoring data, as well as showing some visual examples of common clinical situations and giving practical recommendations for their management.

Progress and indication for use of continuous glucose monitoring in patients with diabetes in pregnancy: a review

Gestational diabetes mellitus is one of the most common endocrine diseases that occur during pregnancy. Disorders of blood glucose metabolism during pregnancy can increase the risk of adverse pregnancy outcomes, such as pregnancy-related hypertension, preeclampsia, eclampsia, miscarriage, macrosomia, and neonatal hypoglycemia. Continuous glucose monitoring (CGM) can safely and effectively monitor blood glucose changes in patients with gestational hyperglycemia, thereby reducing adverse pregnancy outcomes. Hence, this article aimed to provide a comprehensive review of the progress and indications for using CGM in pregnant patients with diabetes. CGM can reduce blood glucose fluctuations and the occurrence of serious hypoglycemia and hyperglycemia events and can provide time in range (TIR). TIR is an important indicator of blood glucose level. Patients with a higher TIR during pregnancy have better gestational outcomes.

The role of technology in the care of diabetes mellitus in pregnancy: an expert review

Diabetes mellitus is one of the most commonly encountered pregnancy complications and is associated with multiple adverse perinatal outcomes. Technology has progressed to address the unique challenges patients face in managing diabetes mellitus in pregnancy. Technology has bolstered diabetes mellitus education with smartphone applications focused on nutrition counseling and carbohydrate intake advice. Continuous glucose monitors and insulin infusion systems have shown benefit by simplifying glycemic monitoring and insulin administration. Improvements in glycemic control and perinatal outcomes have been seen with continuous glucose monitor use when compared with intermittent blood glucose monitoring, and more pregnant people are using insulin pumps instead of multiple daily insulin injections. Hybrid closed-loop systems are emerging and are able to integrate continuous glucose monitoring and insulin pump technologies while maximizing automated features in the nonpregnant population, but these have not been endorsed for use in pregnancy yet. Applying telehealth practices has been associated with high patient satisfaction among those with diabetes mellitus in pregnancy, and leveraging remote patient monitoring through telehealth platforms and short-range wireless technologies can reduce the burden of patient visits. As technology becomes more integrated into routine management of diabetes mellitus in pregnancy, practitioners should emphasize individualized counseling and device selection to ensure patient autonomy and safety.

Management of type 1 diabetes in pregnancy: update on lifestyle, pharmacological treatment, and novel technologies for achieving glycaemic targets

Glucose concentrations within target, appropriate gestational weight gain, adequate lifestyle, and, if necessary, antihypertensive treatment and low-dose aspirin reduces the risk of pre-eclampsia, preterm delivery, and other adverse pregnancy and neonatal outcomes in pregnancies complicated by type 1 diabetes. Despite the increasing use of diabetes technology (ie, continuous glucose monitoring and insulin pumps), the target of more than 70% time in range in pregnancy (TIRp 3·5-7·8 mmol/L) is often reached only in the final weeks of pregnancy, which is too late for beneficial effects on pregnancy outcomes. Hybrid closed-loop (HCL) insulin delivery systems are emerging as promising treatment options in pregnancy. In this Review, we discuss the latest evidence on pre-pregnancy care, management of diabetes-related complications, lifestyle recommendations, gestational weight gain, antihypertensive treatment, aspirin prophylaxis, and the use of novel technologies for achieving and maintaining glycaemic targets during pregnancy in women with type 1 diabetes. In addition, the importance of effective clinical and psychosocial support for pregnant women with type 1 diabetes is also highlighted. We also discuss the contemporary studies examining HCL systems in type 1 diabetes during pregnancies.

Expanding the Role of Continuous Glucose Monitoring in Modern Diabetes Care Beyond Type 1 Disease

Application of continuous glucose monitoring (CGM) has moved diabetes care from a reactive to a proactive process, in which a person with diabetes can prevent episodes of hypoglycemia or hyperglycemia, rather than taking action only once low and high glucose are detected. Consequently, CGM devices are now seen as the standard of care for people with type 1 diabetes mellitus (T1DM). Evidence now supports the use of CGM in people with type 2 diabetes mellitus (T2DM) on any treatment regimen, not just for those on insulin therapy. Expanding the application of CGM to include all people with T1DM or T2DM can support effective intensification of therapies to reduce glucose exposure and lower the risk of complications and hospital admissions, which are associated with high healthcare costs. All of this can be achieved while minimizing the risk of hypoglycemia and improving quality of life for people with diabetes. Wider application of CGM can also bring considerable benefits for women with diabetes during pregnancy and their children, as well as providing support for acute care of hospital inpatients who experience the adverse effects of hyperglycemia following admission and surgical procedures, as a consequence of treatment-related insulin resistance or reduced insulin secretion. By tailoring the application of CGM for daily or intermittent use, depending on the patient profile and their needs, one can ensure the cost-effectiveness of CGM in each setting. In this article we discuss the evidence-based benefits of expanding the use of CGM technology to include all people with diabetes, along with a diverse population of people with non-diabetic glycemic dysregulation.

Ambulatory Glucose Profile Changes During Pregnancy in Women With Type 1 Diabetes Using Intermittently Scanned Continuous Glucose Monitoring Empowered by Personalized Education

The ambulatory glucose profile is a valuable tool in managing type 1 diabetes during pregnancy. Time in range (TIR) in the third trimester is one of the most significant parameters contributing to good pregnancy outcomes. This study aimed to evaluate the effect of intermittently scanned continuous glucose monitoring (isCGM) empowered by education on glucose dynamics and to predict third trimester TIR. Data were retrospectively analyzed from 38 pregnant patients with type 1 diabetes (mean age 30.4 ± 6.4 years, BMI 23.7 ± 3.7 kg/m2, disease duration 15.4 ± 9.5 years, preconception A1C 6.9 ± 1%) who used a first-generation FreeStyle Libre isCGM system for at least 3 months before conception and had sensor data captured >70% of the time the system was used. Patients received personalized education on diabetes and on minimizing hypoglycemia and hyperglycemia using CGM trend arrows and frequent sensor scanning. This intervention improved glycemic parameters of glucose regulation (TIR, glucose management indicator, and mean glucose), hyperglycemia (time above range), glucose variability (SD and coefficient of variation [%CV]), and scanning frequency, but did not improve parameters of hypoglycemia (time below range and a number of low glucose events). Logistic regression analysis showed that the first trimester %CV and scanning frequency contributed to the third trimester TIR (P <0.01, adjusted R2 0.40). This study suggests that the use of isCGM empowered by personalized education improves glycemic control in pregnant women with type 1 diabetes. Scanning frequency and %CV in the first trimester predicts TIR in the third trimester, which could help clinicians intervene early to improve outcomes.

Determination of Time in Range Associated with HbA1c ≤6.5% in Latin American pregnant women diagnosed with type 1 diabetes mellitus using an automated insulin delivery system

AIMS

To determine the correlation between %TIR and HbA1c in pregnant women with type 1 diabetes mellitus (DM1).

METHODS

Diagnostic test study in a prospective cohort of pregnant patients with DM1 using automated insulin delivery system (AID)in Colombia and Chile.

RESULTS

Fifty-two patients were included [mean age 31.8±6.2 years, pregestational HbA1c 7.2% [interquartile range (IQR), 6.5-8.2]. During follow-up, we found a better metabolic control during the second (HbA1c 6.40%, IQR 5.9,7.1) and third trimesters (HbA1c 6.25%;IQR 5.9,6.8). A weak and negative correlation between %TIR and HbA1c was found for all the gestation (Spearman's rank correlation coefficient:-0.22, p:0.0329), and in the second (r :-0.13, p: 0.38) and third trimesters (r:-0.26, p=0.08). %TIR had poor discriminating capacity for predicting HbA1c <6% (area under the curve [AUC], 0.59; 95% confidence interval [CI],0.46-0.72) and for predicting HbA1c <6.5% (AUC, 0.57;95% CI,0.44-0.70). The optimal cutoff points for %TIR were >66.1% for predicting HbA1c <6% (65% sensitivity, 62% specificity) and %TIR >61.1% for HbA1c <6.5% (59% sensitivity, 54% specificity).

CONCLUSION

The correlation between HbA1c and %TIR during pregnancy was weak. The optimal cutoff points for identifying patients with HbA1c <6.0% and <6.5% were %TIR >66.1% and >61.1%, respectively, with moderate sensitivity and specificity.

Insulin pump therapy with and without continuous glucose monitoring in pregnant women with type 1 diabetes: a prospective observational Orchestra Foundation study in Poland

AIMS

The effects of continuous subcutaneous insulin infusion (CSII) therapy with or without continuous glucose monitoring (CGM) on neonatal outcomes and glycemic outcomes of pregnant women with type 1 diabetes (T1D), living in Poland, were assessed.

METHODS

This prospective observational study enrolled women with T1D (N = 481, aged 18-45 years) who were pregnant or planned pregnancy. All used CSII therapy and a subset used CGM with CSII (CSII + CGM). Neonatal outcomes (e.g., rate of large for gestational age [LGA] delivery [birth weight > 90th percentile]) and maternal glycemia (e.g., HbA1c and percentage of time at sensor glucose ranges) were evaluated.

RESULTS

Overall HbA1c at trimesters 1, 2, and 3 was 6.8 ± 1.1% (50.9 ± 12.3 mmol/mol, N = 354), 5.8 ± 0.7% (40.1 ± 8.0 mmol/mol, N = 318), and 5.9 ± 0.7% (41.4 ± 8.0 mmol/mol, N = 255), respectively. A HbA1c target of < 6.0% (42 mmol/mol) at each trimester was achieved by 20.9% (74/354), 65.1% (207/318), and 58.0% (148/255), respectively. For women using CSII + CGM versus CSII only, HbA1c levels at trimesters 1, 2, and 3 were 6.5 ± 0.9% versus 7.1 ± 1.3% (47.8 ± 9.7 mmol/mol versus 54.3 ± 14.0 mmol/mol, p < 0.0001), 5.7 ± 0.6% versus 6.0 ± 0.9% (38.9 ± 6.5 mmol/mol versus 41.6 ± 9.3 mmol/mol, p = 0.0122), and 5.8 ± 0.6% versus 6.1 ± 0.8% (40.3 ± 6.9 mmol/mol versus 42.9 ± 9.1 mmol/mol, p = 0.0117), respectively. For the overall, CSII only, and CSII + CGM groups, rates of LGA delivery were 22.7% (74/326), 24.6% (34/138), and 21.3% (40/188), respectively.

CONCLUSIONS

Observational assessment of women with T1D using CSII therapy demonstrated low HbA1c throughout pregnancy and low rates of LGA. The addition of CGM to CSII therapy compared to CSII therapy alone was associated with some improved maternal glycemic and neonatal outcomes.

GOV IDENTIFIER

NCT01779141 (January 2013).

Time in Range and Pregnancy Outcomes in People with Diabetes Using Continuous Glucose Monitoring

OBJECTIVE

 The international consensus on continuous glucose monitoring (CGM) recommends time in range (TIR) target of >70% for pregnant people. Our aim was to compare outcomes between pregnant people with TIR ≤ versus >70%.

STUDY DESIGN

 This study was a retrospective study of all people using CGM during pregnancy from January 2017 to May 2021 at a tertiary care center. All people with pregestational diabetes who used CGM and delivered at our center were included in the analysis. Primary neonatal outcome included any of the following: large for gestational age, neonatal intensive care unit (NICU) admission, need for intravenous (IV) glucose, or respiratory distress syndrome (RDS). Maternal outcomes included hypertensive disorders of pregnancy and delivery outcomes. Logistic regression was used to estimate unadjusted and adjusted odds ratios (aORs) with 95% confidence intervals (CIs).

RESULTS

 Of 78 people managed with CGM, 65 (80%) met inclusion criteria. While 33 people (50.1%) had TIR ≤70%, 32 (49.2%) had TIR >70%. People with TIR ≤70% were more likely to be younger, have a lower body mass index, and have type 1 diabetes than those with TIR >70%. After multivariable regression, there was no difference in the composite neonatal outcome between the groups (aOR: 0.56, 95% CI: 0.16-1.92). However, neonates of people with TIR ≤70% were more likely to be admitted to the NICU (p = 0.035), to receive IV glucose (p = 0.005), to have RDS (p = 0.012), and had a longer hospital stay (p = 0.012) compared with people with TIR >70%. Furthermore, people with TIR ≤70% were more likely to develop hypertensive disorders (p = 0.04) than those with TIR >70%.

CONCLUSION

 In this cohort, the target of TIR >70% was reached in about one out of two people with diabetes using CGM, which correlated with a reduction in neonatal and maternal complications.

KEY POINTS

· Among people with diabetes, 50% reached the recommended time in range using CGM.. · Time in range >70% was associated with reducing the rate of some neonatal complications.. · Time in range ≤70% was associated with increased risk for adverse maternal outcomes..

Closed-loop insulin delivery in pregnant women with type 1 diabetes (CRISTAL): a multicentre randomized controlled trial - study protocol

BACKGROUND

Despite increasing use of continuous glucose monitoring (CGM) and continuous subcutaneous insulin infusion (CSII, insulin pumps) in type 1 diabetes (T1D) in pregnancy, achieving recommended pregnancy glycaemic targets (3.5-7.8 mmol/L or 63-140 mg/dL) remains challenging. Consequently, the risk of adverse pregnancy outcomes remains high. Outside pregnancy, hybrid closed-loop (HCL) insulin delivery systems have led to a paradigm shift in the management of T1D, with 12% higher time in glucose target range (TIR) compared to conventional CSII. However, most commercially available HCL systems are currently not approved for use in pregnancy. This study aims to evaluate the efficacy, safety and cost-effectiveness of the MiniMed™ 780G HCL system (Medtronic) in T1D in pregnancy.

METHODS

In this international, open-label, randomized controlled trial (RCT), we will compare the MiniMed™ 780G HCL system to standard of care (SoC) in T1D in pregnancy. Women aged 18-45 years with T1D diagnosis of at least one year, HbA1c ≤ 86 mmol/mol (≤ 10%), and confirmed singleton pregnancy up to 11 weeks 6 days will be eligible. After providing written informed consent, all participants will wear a similar CGM system (Guardian™ 3 or Guardian™ 4 CGM) during a 10-day run-in phase. After the run-in phase, participants will be randomised 1:1 to 780G HCL (intervention) or SoC [control, continuation of current T1D treatment with multiple daily injections (MDI) or CSII and any type of CGM] stratified according to centre, baseline HbA1c (< 53 vs. ≥ 53 mmol/mol or < 7 vs. ≥ 7%), and method of insulin delivery (MDI or CSII). The primary outcome will be the time spent within the pregnancy glucose target range, as measured by the CGM at four time points in pregnancy: 14-17, 20-23, 26-29, and 33-36 weeks. Prespecified secondary outcomes will be overnight TIR, time below range (TBR: <3.5 mmol/L or < 63 mg/dL), and overnight TBR. Other outcomes will be exploratory. The planned sample size is 92 participants. The study will end after postpartum discharge from hospital. Analyses will be performed according to intention-to-treat as well as per protocol.

DISCUSSION

This large RCT will evaluate a widely used commercially available HCL system in T1D in pregnancy. Recruitment began in January 2021 and was completed in October 2022. Study completion is expected in May 2023.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04520971. Registration date: August 20, 2020. https://clinicaltrials.gov/ct2/show/NCT04520971.

All Children Deserve to Be Safe, Mothers Too: Evidence and Rationale Supporting CGM Use in Gestational Diabetes Within the Medicaid Population

Gestational diabetes mellitus (GDM) is a common metabolic disease of pregnancy that threatens the health of several million women and their offspring. The highest prevalence of GDM is seen in women of low socioeconomic status. Women with GDM are at increased risk of adverse maternal outcomes, including increased rates of Cesarean section delivery, preeclampsia, perineal tears, and postpartum hemorrhage. However, of even greater concern is the increased risk to the fetus and long-term health of the child due to elevated glycemia during pregnancy. Although the use of continuous glucose monitoring (CGM) has been shown to reduce the incidence of maternal and fetal complications in pregnant women with type 1 diabetes and type 2 diabetes, most state Medicaid programs do not cover CGM for women with GDM. This article reviews current statistics relevant to the incidence and costs of GDM among Medicaid beneficiaries, summarizes key findings from pregnancy studies using CGM, and presents a rationale for expanding and standardizing CGM coverage for GDM within state Medicaid populations.

Research progress in the application of time in range: more than a percentage

ABSTRACT

Glucose monitoring is an important part of medical care in diabetes mellitus, which not only helps assess glycemic control and treatment safety, but also assists with treatment adjustment. With the development of continuous glucose monitoring (CGM), the use of CGM has increased rapidly. With the wealth of glucose data produced by CGM, new metrics are greatly needed to optimally evaluate glucose status and guide the treatment. One of the parameters that CGM provides, time in range (TIR), has been recognized as a key metric by the international consensus. Before the adoption of TIR in clinical practice, several issues including the minimum length of CGM use, the setting of the target range, and individualized TIR goals are summarized. Additionally, we discussed the mounting evidence supporting the association between TIR and diabetes-related outcomes. As a novel glucose metric, it is of interest to compare TIR with other conventional glucose markers such as glycated hemoglobin A1c. It is anticipated that the use of TIR may provide further information on the quality of glucose control and lead to improved diabetes management.

Expert Guidance on Off-Label Use of Hybrid Closed-Loop Therapy in Pregnancies Complicated by Diabetes

Automated insulin delivery (AID) systems have established benefits in terms of glycemic control, health outcomes, and quality of life and are strongly recommended for people with type 1 diabetes outside of pregnancy. While evidence for use of investigational AID systems during pregnancy is promising, data and guidance are still needed regarding use of commercially available systems during pregnancy. Unfortunately, none of the hybrid closed-loop (HCL) systems that are currently available in the United States have glucose targets that are as aggressive as pregnancy glycemic targets, none have a pregnancy-specific algorithm, and none are approved for use during pregnancy. As such, any use of these systems during pregnancy is considered off-label in the United States and would be "assisted" by provider/user techniques. Despite these limitations, many women conceive while using clinically available HCL systems and may be hesitant to cease use during pregnancy. Achievement of strict pregnancy glycemic targets can be difficult, and it is conceivable that selective off-label use of clinically available HCL systems in some women could lead to improved glycemia. We herein offer expert guidance based on clinical experience and available case reports on how to identify appropriate candidates for HCL therapy in pregnancy, how to counsel pregnant women with diabetes on the potential risks and benefits of HCL therapy during pregnancy, and how to manage commercially available systems off-label throughout gestation in an assisted HCL approach.

Observational assessments of the relationship of dietary and pharmacological treatment on continuous measures of dysglycemia over 24 hours in women with gestational diabetes

OBJECTIVES

Studies that use continuous glucose monitoring (CGM) to monitor women with gestational diabetes (GDM), highlight the importance of managing dysglycemia over a 24-hour period. However, the effect of current treatment methods on dysglycemia over 24-hrs are currently unknown. This study aimed to characterise CGM metrics over 24-hrs in women with GDM and the moderating effect of treatment strategy.

METHODS

Retrospective analysis of CGM data from 128 women with GDM in antenatal diabetes clinics. CGM was measured for 7-days between 30-32 weeks gestation. Non-parametric tests were used to evaluate differences of CGM between periods of day (morning, afternoon, evening, and overnight) and between treatment methods (i.e., diet alone or diet+metformin). Exploratory analysis in a subgroup of 34 of participants was performed to investigate the association between self-reported macronutrient intake and glycaemic control.

RESULTS

Glucose levels significantly differed during the day (i.e., morning to evening; P<0.001) and were significantly higher (i.e., mean blood glucose and area under the curve [AUC]) and more variable (i.e., SD and CV) than overnight glucose levels. Morning showed the highest amount of variability (CV; 8.4% vs 6.5%, P<0.001 and SD; 0.49 mmol/L vs 0.38 mmol/L, P<0.001). When comparing treatment methods, mean glucose (6.09 vs 5.65 mmol/L; P<0.001) and AUC (8760.8 vs 8115.1 mmol/L.hr; P<0.001) were significantly higher in diet+metformin compared to diet alone. Finally, the exploratory analysis revealed a favourable association between higher protein intake (+1SD or +92 kcal/day) and lower mean glucose (-0.91 mmol/L p, P=0.02) and total AUC (1209.6 mmol/L.h, P=0.021).

CONCLUSIONS

Glycemia varies considerably across a day, with morning glycemia demonstrating greatest variability. Additionally, our work supports that individuals assigned to diet+metformin have greater difficulty managing glycemia and results suggest that increased dietary protein may assist with management of dysglycemia. Future work is needed to investigate the benefit of increased protein intake on management of dysglycemia.

7. Diabetes Technology: Standards of Care in Diabetes-2023

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Correlations between parameters of glycaemic variability and foetal growth, neonatal hypoglycaemia and hyperbilirubinemia in women with gestational diabetes

The diagnosis of gestational diabetes mellitus (GDM) is important to prevent maternal and neonatal complications. This study aimed to investigate the feasibility of parameters of glycaemic variability to predict neonatal complications in women with GDM. A retrospective study was conducted on pregnant women tested positive at the oral glucose tolerance test (OGTT) during 16-18 or 24-28 weeks of gestation. Glycaemic measures were extracted from patients' glucometers and expanded to obtain parameters of glycaemic variability. Data on pregnancy outcomes were obtained from clinical folders. Descriptive group-level analysis was used to assess trends in glycaemic measures and foetal outcomes. Twelve patients were included and analysed, accounting for 111 weeks of observations. The analysis of trends in parameters of glycaemic variability showed spikes of glycaemic mean, high blood glucose index and J-index at 30-31 weeks of gestation for cases with foetal macrosomia, defined as foetal growth >90° percentile, neonatal hypoglycaemia and hyperbilirubinemia. Specific trends in parameters of glycaemic variability observed at third trimester correlate with foetal outcomes. Further research is awaited to provide evidence that monitoring of glycaemic variability trends could be more clinically informative and useful than standard glycaemic checks to manage women with GDM at delivery.

15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes-2023

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

What's new in the management of type 1 diabetes in pregnancy?

Type 1 diabetes in pregnancy is associated with an increased risk of complications for both mother and fetus. However, managing glycaemia during pregnancy to reduce these risks is challenging, owing to changes in insulin resistance with advancing gestation, as well as increased daily variation in insulin pharmacokinetics. These factors can add significant psychological and daily self-care burden to mothers during what may already be an anxious time. Increasingly, diabetes technologies are being used during pregnancy to improve and facilitate diabetes self-care. While these can be empowering for people with type 1 diabetes, careful consideration is required in relation to how and when these can be continued safely in the inpatient setting (including acute antenatal admissions, labour and delivery) and when extra support is required from adequately trained healthcare professionals. This article describes current forms of diabetes technologies used and the latest national guidance relating to the care of type 1 diabetes in pregnancy.

Carbohydrate Intake and Closed-Loop Insulin Delivery System during Two Subsequent Pregnancies in Type 1 Diabetes

Carbohydrate intake is one of the main determinants of glycemic control. In pregnancy, achievement of tight glycemic control is of utmost importance; however, data on the role of hybrid closed-loop systems (HCLs) in pregnancy are scarce. Therefore, we aimed to assess glycemic control achieved through the use of HCLs, and its association with carbohydrate intake in type 1 diabetes pregnancy. We included data from women with a sensor-augmented pump (SAP) during their first pregnancy and HCL use during the subsequent pregnancy. Student's paired t-test was used to compare data between both pregnancies. Six women were identified, with age 30.2 ± 3.6 vs. 33.0 ± 3.6 years, diabetes duration 23 ± 5 vs. 26 ± 5 years, and baseline HbA1c 6.7 ± 0.7% (50.1 ± 7.7 mmol/mol) vs. 6.3 ± 0.6% (45.2 ± 6.5 mmol/moll) in the first and second pregnancies, respectively. Time with glucose in the range 3.5-7.8 mmol/L was 69.1 ± 6.7 vs. 78.6 ± 7.4%, p = 0.045, with the HCLs compared to SAP. Higher meal frequency, but not the amount of carbohydrate consumption, was associated with more time spent in the target range and lower glycemic variability. HCLs and meal frequency were associated with better glycemic control in a small series of pregnant women with type 1 diabetes. Whether this translates to better perinatal outcomes remains to be seen.

Flash glucose monitoring system in special situations

The management of diabetes mellitus (DM) requires maintaining glycemic control, and patients must keep their blood glucose levels close to the normal range to reduce the risk of microvascular complications and cardiovascular events. While glycated hemoglobin (A1C) is currently the primary measure for glucose management and a key marker for long-term complications, it does not provide information on acute glycemic excursions and overall glycemic variability. These limitations may even be higher in some special situations, thereby compromising A1C accuracy, especially when wider glycemic variability is expected and/or when the glycemic goal is more stringent. To attain adequate glycemic control, continuous glucose monitoring (CGM) is more useful than self-monitoring of blood glucose (SMBG), as it is more convenient and provides a greater amount of data. Flash Glucose Monitoring (isCGM /FGM) is a widely accepted option of CGM for measuring interstitial glucose levels in individuals with DM. However, its application under special conditions, such as pregnancy, patients on hemodialysis, patients with cirrhosis, during hospitalization in the intensive care unit and during physical exercise has not yet been fully validated. This review addresses some of these specific situations in which hypoglycemia should be avoided, or in pregnancy, where strict glycemic control is essential, and the application of isCGM/FGM could alleviate the shortcomings associated with poor glucose control or high glycemic variability, thereby contributing to high-quality care.

Clinical application guidelines for blood glucose monitoring in China (2022 edition)

Glucose monitoring is an important component of diabetes management. The Chinese Diabetes Society (CDS) has been producing evidence-based guidelines on the optimal use of glucose monitoring since 2011. In recent years, new technologies in glucose monitoring and more clinical evidence, especially those derived from Chinese populations, have emerged. In this context, the CDS organised experts to revise the Clinical application guidelines for blood glucose monitoring in China in 2021. In this guideline, we focus on four methods of glucose monitoring that are commonly used in clinical practice, including capillary glucose monitoring, glycated haemoglobin A1c, glycated albumin, and continuous glucose monitoring. We describe the definitions and technical characteristics of these methods, the factor that may interfere with the measurement, the advantages and caveats in clinical practice, the interpretation of glucose metrics, and the relevant supporting evidence. The recommendations for the use of these methods are also provided. The various methods of glucose monitoring have their strengths and limitations and cannot be replaced by one another. We hope that these guidelines could aid in the optimal application of common methods of glucose monitoring in clinical practice for better diabetes care.