Glycated haemoglobin (HbA1c) in mid-pregnancy and perinatal outcomes

Relationship between serum NLRP3 along with its effector molecules and pregnancy outcomes in women with hyperglycemia

OBJECTIVE

The study aims to investigate the levels of serum NLRP3 along with its effector molecules (Caspase-1, IL-1β, and IL-18) in the mid-pregnancy in pregnant women with hyperglycemia, and explore the relationship between NLRP3, along with its effector molecules (Caspase-1, IL-1β, and IL-18) and insulin resistance, as well as pregnancy outcomes.

METHODS

The levels of serum NLRP3 along with its effector molecules (Caspase-1, IL-1β, and IL-18) in three groups of pregnant women with gestational diabetes mellitus (GDM), pregestational diabetes mellitus (PGDM) and normal glucose tolerance (NGT) were measured in mid-pregnancy, and their relationship with insulin resistance and pregnancy outcomes was analyzed. The ROC curve was also used to evaluate the predictive value of serum NLRP3 inflammasome and its effector molecules for pregnancy outcomes.

RESULTS

There were no statistical differences in the general clinical data of the three groups, and the concentrations of serum NLRP3 along with its effector molecules were higher in the GDM and PGDM groups than in the NGT group, and NLRP3 along with its effector molecules were positively correlated with fasting blood glucose, fasting insulin, and insulin resistance index in both groups (r > 0, p < .05). The incidence of preterm delivery, hypertensive disorders of pregnancy, premature rupture of membranes, neonatal hypoglycemia and macrosomia was significantly higher in both groups than in the NGT group (p < .05). The value of the combined serum NLRP3 and its effector molecules in mid-pregnancy to predict adverse pregnancy outcomes was highest, and the AUCs for the combined prediction of late hypertensive disorders of pregnancy, premature rupture of membranes, preterm delivery, neonatal hypoglycemia and macrosomia were 0.84 (95% CI 0.79-0.88, p < .001), 0.81 (95% CI 0.75-0.85, p < .001), 0.76 (95% CI 0.70-0.81, p < .001), 0.76 (95% CI 0.70-0.81, p < .001) and 0.72 (95% CI 0.63-0.81, p < .001), respectively.

CONCLUSIONS

Increased serum NLRP3 along with its effector molecules in pregnant women with hyperglycemia are associated with the levels of insulin resistance and the subsequent development of adverse pregnancy outcomes.

Exposure to Low-Level Air Pollution and Hyperglycemia Markers during Pregnancy: A Repeated Measure Analysis

Epidemiologic evidence has emerged showing an association between exposure to air pollution and increased risks of gestational diabetes mellitus (GDM). This study examines the effect of low-level air pollution exposure on a subclinical biomarker of hyperglycemia (i.e., HbA1c) in pregnant people without diabetes before conception. We measured HbA1c in 577 samples repeatedly collected from 224 pregnant people in Rochester, NY, and estimated residential concentrations of PM2.5 and NO2 using high-resolution spatiotemporal models. We observed a U-shaped trajectory of HbA1c during pregnancy with average HbA1c levels of 5.13 (±0.52), 4.97 (±0.54), and 5.43 (±0.40)% in early-, mid-, and late pregnancy, respectively. After adjustment for the U-shaped trajectory and classic GDM risk factors, each interquartile range increase in 10 week NO2 concentration (8.0 ppb) was associated with 0.09% (95% CI: 0.02 to 0.16%) and 0.18% (95% CI: 0.08 to 0.28%) increases in HbA1c over the entire pregnancy and in late pregnancy, respectively. These associations remained robust among participants without GDM. Using separate distributed lag models, we identified a period between 8th and 14th gestational weeks as critical windows responsible for increased levels of HbA1c measured at 14th, 22nd, and 30th gestational weeks. Our results suggest that low-level air pollution contributes to hyperglycemia in medically low-risk pregnant people.

Regeneratable bioinspired nanochannels for highly sensitive electrochemical detection of glycated albumin

Glycated albumin (GA) has been proposed as a reliable diabetes mellitus marker particularly useful in assessing intermediate glycemic control. Herein, we designed a bioinspired nanochannels for biochemical detection based on the host-guest interaction between β-cyclodextrin and azobenzene. Cyclodextrin was grafted on the inner surface of nanochannels of a nanoporous membrane and azobenzene was tagged to the terminal of GA aptamer, thereby facilitating the orientation of GA aptamer in the nanochannels. The presence of GA was monitored by recording the voltammetric signal of ferricyanide that transported across the nanochannel array. The peak current exhibited a linearity relationship with the GA concentration across a broad range of 1.0 ng mL-1 to 100 μg mL-1, along with a detection limit of 0.18 ng mL-1. Notably, the aptamer could be offloaded under ultraviolet light, regenerating the cyclodextrin functionalized nanochannels for subsequent re-immobilization of the fresh aptamer. The relative standard deviation for seven cycles of regeneration treatment was no more than 1.8 %. The remarkable reusability of the nanochannels offered a cost-effective, sensitive and reproducible aptasensing platform.

Post-load glucose is a stronger predictor of adverse pregnancy outcomes than first-trimester HbA1c in women without gestational diabetes

AIMS/INTRODUCTION

A debate exists on the relation of adverse pregnancy outcomes with glycemic levels in early pregnancy. We aimed to investigate the association of maternal characteristics including post-load glucose and first-trimester HbA1c test results with adverse pregnancy outcomes in women without gestational diabetes mellitus.

MATERIALS AND METHODS

A dataset (January 2011 and September 2017) from a hospital prenatal clinic was explored to find the important predictors of adverse pregnancy outcomes using maternal characteristics and glucose assessments in mothers without gestational diabetes. We used two machine learning algorithms to capture nonlinearity in selecting important maternal characteristics and developed predictive models for each outcome. In total, 1,618 pregnant women were included in the analytic dataset with a mean (SD) age of 26.8 (3.5) years and gravida of 1.7 (0.9).

RESULTS

Important associations were detected between maternal features and primary cesarean section, fetal distress, premature rupture of membranes, macrosomia, small or large for gestational age, APGAR <7 at 1 or 5 min, hyperbilirubinemia, and poly- or oligo-hydramnios. Overall, the predictive models showed good performance and large areas under the curves (0.732, 0.765, 0.646, 0.651, 0.730, 0.646, 0.684, 0.716, and 0.678, respectively). Specifically, they had high positive likelihood ratios.

CONCLUSIONS

High glucose levels were associated with adverse pregnancy outcomes. Post-load glucose was the most reliable test for predicting the outcomes. Overall, fasting blood sugar was of more predictive value than HbA1c. Our study showed that further research should account for the nonlinearity and interactions inherent in the data.

Diabetes and pregnancy study (DAPSY): a 10-year single-center cohort study of pregnancies affected by diabetes

PURPOSE

The aim of our study was to investigate to what degree clinical characteristics can contribute to incidence and structure of pregnancy and childbirth complications in women with diabetes, and to reveal key risk factors for adverse outcomes.

METHODS

We conducted a retrospective single-center cohort study from January 2008 through December 2017, including 3069 singleton pregnancies, affected by type 1 diabetes (T1D, n = 498), type 2 diabetes (T2D, n = 214), and gestational diabetes mellitus (GDM, n = 2357).

RESULTS

More than 10 years duration of T1D associated with increased risk for preterm birth (RR 2.03, 95% CI 1.28-3.20) and preeclampsia (RR 1.57, 95% CI 1.09-2.26). Diabetic nephropathy, same as diabetic proliferative retinopathy, was associated with increased risk of C-section, preeclampsia development, SGA delivery. In patients with T1D who received CSII (12%), we do not report superior outcomes compared to MDI. Pre-pregnancy HbA1c level less than 6.5% reduced the risk of preeclampsia for T1D (RR 0.28, 95% CI 0.19-0.67) and risk of LGA birth for T2D (RR 0.43, 95% CI 0.19-0.92). Achieving glycemic target values by full-term pregnancy reduced the risk of excessive fetal adiposity (RR 0.81 for T1D, RR 0.39 for T2D). For T2D and GDM, the leading risk factors were obesity and chronic hypertension. For patients with GDM, insulin administration and early diagnosis of GDM were the significant risk factors for adverse outcomes.

CONCLUSION

Diabetes during pregnancy is challenging for the clinician, but optimizing glycemic control, treatment regimens, and close attention to comorbidities can help to reduce the risks and ensure appropriate quality diabetes management.

Association between hemoglobin A1c trajectory during pregnancy and adverse birth outcomes among non-gestational diabetic women

AIMS

Previous studies have shown that higher hemoglobin A1c (HbA1c) levels within the normal range during pregnancy can increase the risk of adverse birth outcomes. However, the effects of the longitudinal HbA1c trajectory during pregnancy on adverse birth outcomes among non-gestational diabetic women are poorly characterized. We aimed to identify HbA1c trajectory during pregnancy among non-gestational diabetic women and to estimate their associations with adverse birth outcomes.

METHODS

Data was extracted from the Information System of Guangdong Women and Children Hospital, China, from January 2017 to July 2022. This study involved 13,979 women who did not have gestational diabetes mellitus and underwent repeated HbA1c measurements during pregnancy. Latent mixture modeling was used to identify HbA1c trajectory groups. Logistic regression was applied to explore the associations between HbA1c trajectory groups and adverse birth outcomes, including preterm delivery, low birth weight, macrosomia, small for gestational age, and large for gestational age (LGA).

RESULTS

Three HbA1c trajectory groups were identified: low-stable (range 4.0% [20 mmol/mol]-4.4% [25 mmol/mol]), moderate-stable (range 4.6% [27 mmol/mol]-5.1% [32 mmol/mol]), and elevated-increasing (range 5.0% [31 mmol/mol]-5.6% [38 mmol/mol]). Compared with the low-stable HbA1c group, the elevated-increasing group had a higher risk of preterm delivery and LGA. The adjusted OR (95% CIs) were 1.67 (1.13, 2.49) and 1.47 (1.01, 2.12) for preterm delivery and LGA, respectively.

CONCLUSIONS

Among non-gestational diabetic women, the elevated-increasing HbA1c trajectory group was associated with a higher risk of preterm delivery and LGA. This finding emphasizes the importance of maintaining optimal HbA1c levels throughout pregnancy.

Pregnancy History at 40 Years of Age as a Marker of Cardiovascular Risk

BACKGROUND

Individual pregnancy complications are associated with increased maternal risk of cardiovascular disease. We assessed the link between a woman's total pregnancy history at 40 years of age and her relative risk of dying from atherosclerotic cardiovascular disease (ASCVD).

METHODS AND RESULTS

This population-based prospective study combined several Norwegian registries covering the period 1967 to 2020. We identified 854 442 women born after 1944 or registered with a pregnancy in 1967 or later, and surviving to 40 years of age. The main outcome was the time to ASCVD mortality through age 69 years. The exposure was a woman's number of recorded pregnancies (0, 1, 2, 3, or 4) and the number of those with complications (preterm delivery <35 gestational weeks, preeclampsia, placental abruption, perinatal death, and term or near-term birth weight <2700 g). Cox models provided estimates of hazard ratios across exposure categories. The group with the lowest ASCVD mortality was that with 3 pregnancies and no complications, which served as the reference group. Among women reaching 40 years of age, risk of ASCVD mortality through 69 years of age increased with the number of complicated pregnancies in a strong dose-response fashion, reaching 23-fold increased risk (95% CI, 10-51) for women with 4 complicated pregnancies. Based on pregnancy history alone, 19% of women at 40 years of age (including nulliparous women) had an increased ASCVD mortality risk in the range of 2.5- to 5-fold.

CONCLUSIONS

Pregnancy history at 40 years of age is strongly associated with ASCVD mortality. Further research should explore how much pregnancy history at 40 years of age adds to established cardiovascular disease risk factors in predicting cardiovascular disease mortality.

Early to mid-pregnancy HbA1c levels and its association with adverse pregnancy outcomes in three low middle-income countries in Asia and Sub-Saharan Africa

BACKGROUND

Hyperglycemia during pregnancy leads to adverse maternal and fetal outcomes. Thus, strict monitoring of blood glucose levels is warranted. This study aims to determine the association of early to mid-pregnancy HbA1c levels with the development of pregnancy complications in women from three countries in South Asia and Sub-Saharan Africa.

METHODS

We performed a secondary analysis of the AMANHI (Alliance for Maternal and Newborn Health Improvement) cohort, which enrolled 10,001 pregnant women between May 2014 and June 2018 across Sylhet-Bangladesh, Karachi-Pakistan, and Pemba Island-Tanzania. HbA1c assays were performed at enrollment (8 to < 20 gestational weeks), and epidemiological data were collected during 2-3 monthly household visits. The women were followed-up till the postpartum period to determine the pregnancy outcomes. Multivariable logistic regression models assessed the association between elevated HbA1c levels and adverse events while controlling for potential confounders.

RESULTS

A total of 9,510 pregnant women were included in the analysis. The mean HbA1c level at enrollment was found to be the highest in Bangladesh (5.31 ± 0.37), followed by Tanzania (5.22 ± 0.49) and then Pakistan (5.07 ± 0.58). We report 339 stillbirths and 9,039 live births. Among the live births were 892 preterm births, 892 deliveries via cesarean section, and 532 LGA babies. In the multivariate pooled analysis, maternal HbA1c levels of ≥ 6.5 were associated with increased risks of stillbirths (aRR = 6.3, 95% CI = 3.4,11.6); preterm births (aRR = 3.5, 95% CI = 1.8-6.7); and Large for Gestational Age (aRR = 5.5, 95% CI = 2.9-10.6).

CONCLUSION

Maternal HbA1c level is an independent risk factor for predicting adverse pregnancy outcomes such as stillbirth, preterm birth, and LGA among women in South Asia and Sub-Saharan Africa. These groups may benefit from early interventional strategies.

Pre-pregnancy body mass index and glycated-hemoglobin with the risk of metabolic diseases in gestational diabetes: a prospective cohort study

Background

Metabolic diseases during pregnancy result in negative consequences for mothers. Pre-pregnancy body mass index (BMI) and late-pregnancy glycated-hemoglobin (HbA1c) are most important factors independently affecting the risk of gestational diabetes mellitus (GDM). However how both affect the combined risk of other metabolic diseases in women with GDM is unclear. The study aims to investigate the influence of pre-pregnancy BMI and pregnancy glycemic levels on other gestational metabolic diseases in women with GDM.

Methods

Pregnancies with GDM from January 2015 to December 2018 in the Xi'an longitudinal mother-child cohort study (XAMC) were retrospectively enrolled. Those without other metabolic diseases by the time of oral glucose tolerance test (OGTT) detection were finally recruited and divided into four groups by pre-pregnancy BMI (Underweight <18.5kg/m2; Normal weight 18.5-23.9 kg/m2; Overweight 24.0-27.9 kg/m2; Obesity ≥28.0 kg/m2, respectively) or two groups by HbA1c in late pregnancy (normal HbA1c<5.7%; high HbA1c≥5.7%). Multivariate logistic regression analysis was used to identify risk factors. Interaction between pre-pregnancy BMI (reference group 18.5-23.9 kg/m2) and HbA1c (reference group <5.7%) was determined using strata-specific analysis.

Results

A total of 8928 subjects with GDM were included, 16.2% of which had a composite of metabolic diseases. The pre-pregnancy overweight and obesity, compared with normal BMI, were linked to the elevated risk of the composite of metabolic diseases, particularly pre-eclampsia (both P <0.001) and gestational hypertension (both P <0.001). Meanwhile, patients with high HbA1c had an obvious higher risk of pre-eclampsia (P< 0.001) and gestational hypertension (P= 0.005) compared to those with normal HbA1c. In addition, there were significant interactions between pre-pregnancy BMI and HbA1c (P< 0.001). The OR of pre-pregnancy BMI≥ 28 kg/m2 and HbA1c≥ 5.7% was 4.46 (95% CI: 2.85, 6.99; P< 0.001). The risk of other metabolic diseases, except for pre-eclampsia (P= 0.003), was comparable between the two groups of patients with different HbA1c levels at normal pre-pregnancy BMI group. However, that was remarkably elevated in obese patients (P= 0.004), particularly the risk of gestational hypertension (P= 0.004).

Conclusion

Pre-pregnancy overweight/obesity and late-pregnancy high HbA1c increased the risk of other gestational metabolic diseases of women with GDM. Monitoring and controlling late-pregnancy HbA1c was effective in reducing metabolic diseases, particularly in those who were overweight/obese before conception.

Trimester-specific reference intervals for hemoglobin A1c in non-diabetic pregnancy in a Chinese population

BACKGROUND

Physiological glycated hemoglobin (HbA1c) values in each trimester are not well defined. This study aimed to determine trimester-specific reference intervals for HbA1c levels in non-diabetic pregnant women in China.

METHODS

In this cross-sectional study, 5,042 Chinese pregnant women from 6 to 41 weeks of gestation were screened. An inclusion of 4,134 non-diabetic women was made to determine the reference intervals, they were divided into three trimesters: trimester 1 (T1), 6 weeks to 13 weeks + 6 days, trimester 2 (T2), 14 weeks to 27 weeks + 6 days, and trimester 3 (T3), 28 weeks to 41 weeks + 6 days. A total of 4,134 women (T1 n = 760, T2 n = 1,953, and T3 n = 1,421) provided blood samples which were analyzed for HbA1c concentrations. HbA1c was measured using high-performance liquid chromatography. The median and percentile (2.5th to 97.5th) for the HbA1c reference intervals were calculated for each trimester.

RESULTS

In total, 8,732 HbA1c measurements were taken. Reference intervals for HbA1c expressed as median and percentile (2.5th to 97.5th) for each trimester were: T1: 4.7 (4.0-5.5%), T2: 4.5 (3.9-5.3%), and T3: 4.8 (4.1-5.7%) respectively. The HbA1c levels were significantly lower in the second trimester compared to those in the first trimester (p < 0.0001), and higher in the third trimester compared to the second trimester (p < 0.0001).

CONCLUSIONS

The reference intervals for HbA1c levels were 3.9-5.7% with upper limits of 5.5% in the first trimester, 5.3% in the second trimester, and 5.7% in the third trimester. These findings highlight the importance of considering trimester-specific reference intervals for HbA1c in non-diabetic pregnant women to promote maternal and fetal health.

Invited Commentary: Beyond Barker-Mothers Are the Ones at Risk

Dr. David Barker hypothesized that low birth weight (LBW) is the result of inadequate fetal nutrition, leading to increased risk of cardiovascular disease (CVD) in the offspring. This hypothesis has stimulated thousands of reports on low birth weight (LBW) and CVD risk. One problem with this association is that many LBW infants are small because they are preterm, not growth-restricted. A second problem is that maternal CVD risk factors confound the association. In an accompanying article, Lu et al. (Am J Epidemiol. 2023;192(6):866-877) address both concerns. Using population data from Sweden and Denmark, the authors estimated CVD incidence among offspring born small for gestational age (SGA). The smallest 3% had a CVD hazard ratio of 1.44 (95% confidence interval: 1.38, 1.51). Even this moderate risk mostly evaporated in sibship analysis, which controlled for unmeasured maternal CVD risk factors (hazard ratio = 1.11, 95% confidence interval: 0.99, 1.25). The risk highlighted by Barker is negligible, especially when compared with a more urgent health issue-cardiovascular risk in women with pregnancy complications. Mothers of SGA infants have up to a 3-fold CVD risk, and mothers with preeclampsia and preterm delivery have up to a 9-fold risk. Pregnancy complications thus provide an early marker of a woman's propensity to develop CVD, and perhaps an opportunity for early intervention. From a public health perspective, Barker's hypothesis about CVD risk in LBW offspring is less compelling than the question of CVD risk among mothers with pregnancy complications. This article is part of a Special Collection on ABC.