Time in Range in Pregnancy: Is There a Role?

Continuous glucose monitoring (CGM) is being used with increasing frequency as an adjunct to self-monitoring of blood glucose in pregnancy, and novel targets based on CGM data are becoming standardized. This adoption of CGM is the result of its improving accuracy, patient preference, and evolving data demonstrating associations of novel targets such as time in range (TIR) with pregnancy and neonatal outcomes. A greater understanding of the relationship of various CGM metrics to outcomes in pregnancy complicated by diabetes is needed. It is clear that TIR parameters need to be uniquely lower for pregnant women than for nonpregnant individuals. CGM technology is also an integral part of hybrid closed-loop insulin delivery systems. These insulin delivery systems will be a significant advance in the management of diabetes during pregnancy if they can achieve the pre- and postprandial targets required for pregnancy and optimize TIR.

Climate factors and gestational diabetes mellitus risk - a systematic review.

BACKGROUND: Current and projected increases in global temperatures and extreme climate events have led to heightened interest in the impact of climate factors (i.e. ambient temperature, season/seasonality, and humidity) on human health. There is growing evidence that climate factors may impact metabolic function, including insulin sensitivity. Gestational diabetes mellitus (GDM) is a common pregnancy complication, with an estimated global prevalence of up to 14%. While lifestyle and genetic risk factors for GDM are well established, environmental factors may also contribute to GDM risk. Previous reviews have summarized the growing evidence of environmental risk factors for GDM including endocrine disrupting chemicals and ambient air pollution. However, studies of the effects of climate factors on GDM risk have not been systematically evaluated. Therefore, we conducted a systematic review to summarize and evaluate the current literature on the associations of climate factors with GDM risk. METHODS: We conducted systematic searches in PubMed and EMBASE databases for original research articles on associations of climate factors (i.e. ambient temperature, season/seasonality, and humidity) with GDM and/or related glycemic outcomes for all publication dates through September 20th, 2020. RESULTS: Our search identified 16 articles on the associations of ambient temperature and/or season with GDM and maternal glycemic outcomes during pregnancy, which were included in this review. Despite inconsistencies in exposure and outcome assessment, we found consistent evidence of a seasonal effect on GDM risk, with higher prevalence of GDM and higher pregnancy glucose levels in summer months. We found suggestive evidence of an association between higher ambient temperature and elevated glucose levels from GDM screening tests. CONCLUSION: Climate factors may be associated with GDM risk. However, further research is needed to evaluate these associations and to elucidate the specific mechanisms involved.

Urinary concentrations of parabens mixture and pregnancy glucose levels among women from a fertility clinic.

BACKGROUND: A number of endocrine disrupting chemicals (EDC) have been associated with gestational diabetes (GDM) risk factors. However, no human study has investigated the association between pregnancy exposure to parabens, a class of EDCs, and pregnancy glucose levels, a risk factor for GDM. Furthermore, little is known about this association in subfertile women-a group at high risk of GDM. METHODS: A total of 241 women from the Environment and Reproductive Health Study had data available on 1st and/or 2nd trimester urinary methylparaben, propylparaben, and butylparaben concentrations, and blood glucose levels after the glucose loading test (GLT), a non-fasting 50 g glucose loading test taken at late 2nd trimester. Trimester-specific associations between specific gravity adjusted methylparaben, butylparaben, and propylparaben with adjusted mean of pregnancy glucose levels were evaluated in linear regression models, using quartiles of each paraben's distribution, and as a paraben mixture, using mutual adjustment and Bayesian kernel machine regression (BKMR), a recently proposed method for investigating chemical mixtures that flexibly models the joint effect of chemicals. RESULTS: Investigating parabens one at the time did not provide any significant results. When investigating parabens as a chemical mixture with both multiple regression and BKMR, we observed positive associations of butylparaben (e.g comparing the 4th and 1st quartiles) with glucose levels, for both the 1st trimester (adjusted difference=12.5 mg/dL; 95% CI: 0.9, 24.2) and 2nd trimester (adjusted difference=11.2 mg/dL; 95% CI: 0.2, 22.3), and a negative association between 1st trimester propylparaben and glucose (adjusted difference=-22.3 mg/dL; 95% CI: -43.2, -1.4). CONCLUSIONS: We found 1st trimester butylparaben and propylparaben urinary concentrations to be associated with glucose levels in a pregnancy cohort of women at high risk of GDM, even after adjusting for potential confounders. Because exposure to parabens is widespread, these findings may suggest further investigating the effects of this chemical class on pregnancy health.

Application of One-Step IADPSG Versus Two-Step Diagnostic Criteria for Gestational Diabetes in the Real World: Impact on Health Services, Clinical Care, and Outcomes.

PURPOSE OF REVIEW: This paper seeks to summarize the impact of the one-step International Association of Diabetes and Pregnancy Study Groups (IADPSG) versus the two-step gestational diabetes mellitus (GDM) criteria with regard to prevalence, outcomes, healthcare delivery, and long-term maternal metabolic risk. RECENT FINDINGS: Studies demonstrate a 1.03-3.78-fold rise in the prevalence of GDM with IADPSG criteria versus baseline criteria. Women with GDM by IADPSG criteria have more adverse pregnancy outcomes than women with normal glucose tolerance (NGT). Treatment of GDM by IADPSG criteria may be cost effective. Use of the fasting glucose as a screen before the 75-g oral glucose tolerance test to rule out GDM with fasting plasma glucose (FPG) < 4.4 (80 mg/dl) and rule in GDM with FPG ≥ 5.1 mmol/l (92 mg/dl) reduces the need for OGTT by 50% and its cost and inconvenience. The prevalence of postpartum abnormal glucose metabolism is higher for women with GDM diagnosed by IADPSG criteria versus that for women with NGT. Data support the use of IADPSG criteria, if the cost of diagnosis and treatment can be controlled and if lifestyle can be optimized to reduce the risk of future diabetes.

Management of Type 1 Diabetes in Pregnancy.

Women with type 1 diabetes (T1DM) have unique needs during the preconception, pregnancy, and postpartum periods. Preconception counseling is essential for women with T1DM to minimize pregnancy risks. The goals of preconception care should be tight glycemic control with a hemoglobin A1c (A1C) < 7 % and as close to 6 % as possible, without significant hypoglycemia. This will lower risks of congenital malformations, preeclampsia, and perinatal mortality. The safety of medications should be assessed prior to conception. Optimal control of retinopathy, hypertension, and nephropathy should be achieved. During pregnancy, the goal A1C is near-normal at <6 %, without excessive hypoglycemia. There is no clear evidence that continuous subcutaneous insulin infusion (CSII) versus multiple daily injections (MDI) is superior in achieving the desired tight glycemic control of T1DM during pregnancy. Data regarding continuous glucose monitoring (CGM) in pregnant women with T1DM is conflicting regarding improved glycemic control. However, a recent CGM study does provide some distinct patterns of glucose levels associated with large for gestational age infants. Frequent eye exams during pregnancy are essential due to risk of progression of retinopathy during pregnancy. Chronic hypertension treatment goals are systolic blood pressure 110-129 mmHg and diastolic blood pressure 65-79 mmHg. Labor and delivery target plasma glucose levels are 80-110 mg/dl, and an insulin drip is recommended to achieve these targets during active labor. Postpartum, insulin doses must be reduced and glucoses closely monitored in women with T1DM because of the enhanced insulin sensitivity after delivery. Breastfeeding is recommended and should be highly encouraged due to maternal benefits including increased insulin sensitivity and weight loss and infant and childhood benefits including reduced prevalence of overweight. In this article, we discuss the care of pregnant patients with T1DM.

Race/ethnicity, educational attainment, and pregnancy complications in New York City women with pre-existing diabetes.

BACKGROUND: More women are entering pregnancy with pre-existing diabetes. Disease severity, glycaemic control, and predictors of pregnancy complications may differ by race/ethnicity or educational attainment, leading to differences in adverse pregnancy outcomes. METHODS: We used linked New York City hospital record and birth certificate data for 6291 singleton births among women with pre-existing diabetes between 1995 and 2003. We defined maternal race/ethnicity as non-Hispanic white, non-Hispanic black, Hispanic, South Asian, and East Asian, and education level as <12, 12, and >12 years. Our outcomes were pre-eclampsia, preterm birth (PTB) (<37 weeks gestation and categorised as spontaneous or medically indicated), as well as small-for-gestational age (SGA) and large-for-gestational age (LGA). Using multivariable binomial regression, we estimated the risk ratios for pre-eclampsia, SGA, and LGA. We used multivariable multinomial regression to estimate odds ratios (OR) for PTB. RESULTS: Compared with non-Hispanic white women with pre-existing diabetes, non-Hispanic black and Hispanic women with pre-existing diabetes had a 1.50-fold increased risk of pre-eclampsia compared with non-Hispanic whites with pre-existing diabetes, after full adjustment. Non-Hispanic black and Hispanic women with pre-existing diabetes had adjusted ORs of 1.72 [adj. 95% confidence interval (CI) 1.38, 2.15] and 1.65 [adj.95% CI 1.32, 2.05], respectively, for medically indicated PTB. South Asian women with pre-existing diabetes had the highest risk for having an SGA infant [adj. OR: 2.29; adj. 95% CI 1.73, 3.03]. East Asian ethnicity was not associated with these pregnancy complications. CONCLUSIONS: Non-Hispanic black, Hispanic, and South Asian women with pre-existing diabetes may benefit from targeted interventions to improve pregnancy outcomes.

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.

Performance of the Dexcom G7 Continuous Glucose Monitoring System in Pregnant Women with Diabetes.

Background: We evaluated accuracy and safety of a seventh-generation real-time continuous glucose monitoring (CGM) system during pregnancy. Materials and Methods: Evaluable data for accuracy analysis were obtained from 96 G7 sensors (Dexcom, Inc.) worn by 96 of 105 enrolled pregnant women with type 1 (n = 59), type 2 (n = 21), or gestational diabetes (n = 25). CGM values were compared with arterialized venous glucose values from the YSI comparator instrument during 6-h clinic sessions at different time points throughout the sensors' 10-day wear period. The primary endpoint was the proportion of CGM values in the 70-180 mg/dL range within 15% of comparator glucose values. Secondary endpoints included the proportion of CGM values within 20% or 20 mg/dL of comparator values ≥ or <100 mg/dL, respectively (the %20/20 agreement rate). Results: Of the 1739 pairs with CGM in the 70-180 mg/dL range, 83.2% were within 15% of comparator values. The lower bound of the 95% confidence interval was 79.8%. Of the 2102 pairs with CGM values in the 40-400 mg/dL range, the %20/20 agreement rate was 92.5%. Of the 1659 pairs with comparator values in the 63-140 mg/dL range, the %20/20 agreement rate was 92.3%. The %20/20 agreement rates on days 1, 4 and 7, and 10 were 78.6%, 96.3%, and 97.3%, respectively. Consensus error grid analysis showed 99.8% of pairs in the clinically acceptable A and B zones. There were no serious adverse events. The sensors' 10-day survival rate was 90.3%. Conclusion: The G7 system is accurate and safe during pregnancies complicated by diabetes and does not require confirmatory fingerstick testing. Clinical Trial Registration: clinicaltrials.gov NCT04905628.

Cohort profile: the Environmental Reproductive and Glucose Outcomes (ERGO) Study (Boston, Massachusetts, USA) - a prospective pregnancy cohort study of the impacts of environmental exposures on parental cardiometabolic health.

PURPOSE: Pregnancy and the postpartum period are increasingly recognised as sensitive windows for cardiometabolic disease risk. Growing evidence suggests environmental exposures, including endocrine-disrupting chemicals (EDCs), are associated with an increased risk of pregnancy complications that are associated with long-term cardiometabolic risk. However, the impact of perinatal EDC exposure on subsequent cardiometabolic risk post-pregnancy is less understood. The Environmental Reproductive and Glucose Outcomes (ERGO) Study was established to investigate the associations of environmental exposures during the perinatal period with post-pregnancy parental cardiometabolic health. PARTICIPANTS: Pregnant individuals aged ≥18 years without pre-existing diabetes were recruited at <15 weeks of gestation from Boston, Massachusetts area hospitals. Participants completed ≤4 prenatal study visits (median: 12, 19, 26, 36 weeks of gestation) and 1 postpartum visit (median: 9 weeks), during which we collected biospecimens, health histories, demographic and behavioural data, and vitals and anthropometric measurements. Participants completed a postpartum fasting 2-hour 75 g oral glucose tolerance test. Clinical data were abstracted from electronic medical records. Ongoing (as of 2024) extended post-pregnancy follow-up visits occur annually following similar data collection protocols. FINDINGS TO DATE: We enrolled 653 unique pregnancies and retained 633 through delivery. Participants had a mean age of 33 years, 10% (n=61) developed gestational diabetes and 8% (n=50) developed pre-eclampsia. Participant pregnancy and postpartum urinary phthalate metabolite concentrations and postpartum glycaemic biomarkers were quantified. To date, studies within ERGO found higher exposure to phthalates and phthalate mixtures, and separately, higher exposure to radioactive ambient particulate matter, were associated with adverse gestational glycaemic outcomes. Additionally, certain personal care products used in pregnancy, notably hair oils, were associated with higher urinary phthalate metabolite concentrations, earlier gestational age at delivery and lower birth weight. FUTURE PLANS: Future work will leverage the longitudinal data collected on pregnancy and cardiometabolic outcomes, environmental exposures, questionnaires, banked biospecimens and paediatric data within the ERGO Study.

11. Chronic Kidney Disease and Risk Management: 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.

3. Prevention or Delay of Type 2 Diabetes and Associated Comorbidities: 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.

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.

10. Cardiovascular Disease and Risk Management: 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.

12. Retinopathy, Neuropathy, and Foot Care: 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.

1. Improving Care and Promoting Health in Populations: 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.

8. Obesity and Weight Management for the Prevention and Treatment of Type 2 Diabetes: 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.

13. Older Adults: 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.

17. Diabetes Advocacy: 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.

16. Diabetes Care in the Hospital: 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.