What is the role of glycemic control in the development of preeclampsia among women with type 1 diabetes?

Continuous Glucose Monitoring-Derived Differences in Pregnancies With and Without Adverse Perinatal Outcomes

OBJECTIVE

To evaluate whether continuous glucose monitoring (CGM)-derived glycemic patterns observed throughout pregnancy were associated with adverse perinatal outcomes, specifically fetal growth disorders and hypertensive disorders of pregnancy (HDP).

METHODS

We conducted a prospective observational study of individuals with viable singleton pregnancies and screening hemoglobin A 1c levels less than 6.5%. Those with preexisting diabetes were excluded. Enrollment occurred at the earliest gestational age before 17 weeks. Participants wore blinded continuous glucose monitors consecutively as willing until delivery. Those with at least 14 days of CGM data were included in analysis. Rates of large-for-gestational-age (LGA) neonates, small-for-gestational age (SGA) neonates, and HDP were assessed. Continuous glucose monitoring-derived glycemic metrics were calculated, including mean glucose level and percent time above and below thresholds. Two-sample t tests were used to compare glycemic metrics between participants with and without adverse perinatal outcomes.

RESULTS

Of 937 participants enrolled, 760 met inclusion criteria. Those delivering LGA neonates or who were diagnosed with HDP had higher mean glucose levels (102±9 vs 100±8, P =.01 and 103±8 vs 99±8, P <.001) and spent more time above 120 mg/dL (median 16% vs 12%, P =.006, and 16% vs 12%, P <.001, respectively) and above 140 mg/dL (median 3.9% vs 2.8%, P =.006, and 3.5% vs 2.8%, P <.001, respectively) throughout gestation than those without these outcomes. These findings were present regardless of gestational diabetes mellitus status. Participants with SGA neonates had lower mean glucose levels (97±7 vs 101±8, P =.01) and spent less time above 140 mg/dL (median 1.6% vs 2.3%, P =.01) and more time below 63 mg/dL (median 3.0% vs 2.3%, P =.02) than those without SGA neonates.

CONCLUSION

Individuals with LGA neonates or HDP exhibit a slightly higher mean glucose levels and spend more time hyperglycemic in early pregnancy than those who do not experience these outcomes.

Clinical Risk Factors and First Gestational 75 g OGTT May Predict Recurrent and New-Onset Gestational Diabetes in Multiparous Women

Background: Women who experience gestational diabetes mellitus (GDM) during their first pregnancy are at a high risk of developing GDM again in subsequent pregnancies. Even mothers with no previous history of GDM may develop the condition in a new pregnancy. Methods: In this retrospective cross-sectional observational study, 759 multiparous women tested for GDM in two successive pregnancies using the 75 g OGTT (IADPSG criteria) were enrolled. The OGTT was performed at 24-28 weeks' gestation or earlier if there was a history of GDM. Participants were categorized into four groups: women with normal glucose tolerance (NGT) in both pregnancies (n = 493), women with a first occurrence of GDM in their second pregnancy (n = 74), women with non-recurrent GDM in their second pregnancy (n = 92), and women with recurrent GDM in their second pregnancy (n = 100). Results: Intergroup comparisons revealed clinical predictors of GDM in the first pregnancy (family history of type 2 diabetes, PCOS, advanced maternal age, pregravid obesity) and in the second pregnancy (interpregnancy BMI gain), as well as predictors of recurrent GDM (pregravid obesity, PCOS). A positive correlation was observed between the OGTT glucose levels of consecutive pregnancies. Adjusted logistic regression indicated that a higher 1-h post-load glucose level (≥130 mg/dL) during the first pregnancy significantly increased the likelihood of new-onset GDM in the second pregnancy (OR: 2.496), whereas a higher 2-h post-load glucose level (≥153 mg/dL) at the first diagnostic OGTT increased the likelihood of recurrent GDM (OR: 2.214). Conclusions: Clinical risk factors and post-load glucose levels during the first gestational 75 g OGTT can help predict new-onset or recurrent GDM in multiparous women.

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.

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.

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.

Doppler Indices of the Uterine, Umbilical and Fetal Middle Cerebral Artery in Diabetic versus Non-Diabetic Pregnancy: Systematic Review and Meta-Analysis

Background and Objectives: The aim of this study was to assess the differences in Doppler indices of the uterine (Ut), umbilical (UA), and middle cerebral artery (MCA) in diabetic versus non-diabetic pregnancies by conducting a comprehensive systematic review of the literature with a meta-analysis. Materials and Methods: PubMed, Web of Science, and SCOPUS were searched for studies that measured the pulsatility index (PI), resistance index (RI), and systolic/diastolic ratio index (S/D ratio) of the umbilical artery, middle cerebral artery, and uterine artery in diabetic versus non-diabetic pregnancies. Two reviewers independently evaluated the eligibility of studies, abstracted data, and performed quality assessments according to standardized protocols. The standardized mean difference (SMD) was used as a measure of effect size. Heterogeneity was assessed using the I2 statistic. Publication bias was evaluated by means of funnel plots. Results: A total of 62 publications were included in the qualitative and 43 in quantitative analysis. The UA-RI, UtA-PI, and UtA-S/D ratios were increased in diabetic compared with non-diabetic pregnancies. Subgroup analysis showed that levels of UtA-PI were significantly higher during the third, but not during the first trimester of pregnancy in diabetic versus non-diabetic pregnancies. No differences were found for the UA-PI, UA-S/D ratio, MCA-PI, MCA-RI, MCA-S/D ratio, or UtA-RI between diabetic and non-diabetic pregnancies. Conclusions: This meta-analysis revealed the presence of hemodynamic changes in uterine and umbilical arteries, but not in the middle cerebral artery in pregnancies complicated by diabetes.