Is There a Role for HbA1c in Pregnancy?

Effects of physical activity on blood lipids and HbA1c in healthy pregnant women: the FitMum randomized controlled trial

OBJECTIVE

Maternal blood lipid and glucose concentrations during pregnancy affect fetal growth and the risk of pregnancy and delivery complications. We aimed to investigate the effects of physical activity (PA) during pregnancy on maternal blood lipid and hemoglobin A1c (HbA1c) concentrations. We hypothesized that higher PA was associated with improved lipid profile and glycemic control.

METHODS

In a secondary analysis of a randomized controlled trial, we included 216 pregnant women before week 15+0 and tested the effects of two different PA interventions throughout pregnancy compared to standard care on maternal blood lipid and HbA1c concentrations. Additionally, we investigated the effect of PA per se measured by an activity tracker. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglyceride, and HbA1c concentrations were measured at week ≤15+0, 28+0-6, 34+0-6, and at delivery (week 32+1 to 42+0). Effects of the interventions and PA per se were tested using linear mixed effects models and linear regression analyses, respectively.

RESULTS

No effects of the PA interventions were detected on maternal lipids or HbA1c during pregnancy. In PA per se analyses, more minutes per week of moderate-to-vigorous intensity PA were associated with less increase in TC (-1.3E-04, p=0.020) and LDL-C (-8.5E-05, p=0.035) as pregnancy progresses. More active kilocalories were associated with less increase in TC (-5.5E-05, p<0.001), HDL-C (-9.5E-06, p=0.024), and LDL-C (-3.2E-05, p=0.005).

CONCLUSION

Whilst there were no effects of offering PA interventions, higher PA was associated with reduced increases in total cholesterol, HDL-C, and LDL-C as pregnancy progressed.

Predelivery HbA1c levels and their relationship with adverse perinatal outcomes in women with normal 75-g OGTT

PURPOSE

To analyze the elevation of HbA1c before full-term delivery in single pregnancy with normal 75 g- Oral glucose tolerance test (OGTT) screening and its association with adverse perinatal outcomes.

METHODS

From January to December 2022, an observational prospective study was conducted in a Single centre in China. 365 single pregnant women with normal OGTT were included in the study. HbA1c was measured during OGTT and before full-term delivery, and perinatal outcomes were collected. Participants' pre-delivery HBA1c values were analyzed and perinatal outcomes were compared. Logistic regression analysis was used for independent risk factors associated with elevated pre-delivery HbA1c ≥ 6.0%. The predictive value and truncation value were analyzed by ROC curve.

RESULTS

15.89% (58/365) of the Participants had a pre-delivery HBA1C value ≥ 6.0%. The incidence of neonatal asphyxia (13.79%, vs. 3.45%, vs. 2.26%, P = 0.007) and amniotic fluid fecal staining (29.31%, vs. 12.64%, vs. 12.03%, P = 0.004) were significantly increased in this group. The independent risk factor associated with pre-delivery HBA1c ≥ 6.0% was the fasting blood glucose(FBG) value of OGTT (OR = 51.308, 95% CI 12.93-203.67, P < 0.01) and the HBA1c value measured during OGTT (OR = 3.608, 95% CI 1.432-9.151, P = 0.007). When FBG was < 4.18 mmol/L and HBA1c was < 5.51%, The accuracy of predicting the pre-delivery HBA1c < 6.0% was 98.2%.

CONCLUSIONS

15.89% of the single pregnancy with normal OGTT had HbA1c ≥ 6.0% before full-term delivery, and they had an increased incidence of neonatal asphyxia and amniotic fluid fecal staining. When the FBG ≥ 4.18 mmol/l or the HBA1c ≥ 5.51% during the OGTT screening, repeated OGTT were recommended in late pregnancy.

Associations of serum D-dimer and glycosylated hemoglobin levels with third-trimester fetal growth restriction in gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is a special type of diabetes that commonly occurs in women during pregnancy and involves impaired glucose tolerance and abnormal glucose metabolism; GDM is diagnosed for the first time during pregnancy and can affect fetal growth and development.

AIM

To investigate the associations of serum D-dimer (D-D) and glycosylated hemoglobin (HbA1c) levels with third-trimester fetal growth restriction (FGR) in GDM patients.

METHODS

The clinical data of 164 pregnant women who were diagnosed with GDM and delivered at the Obstetrics and Gynecology Hospital of Fudan University from January 2021 to January 2023 were analyzed retrospectively. Among these women, 63 whose fetuses had FGR were included in the FGR group, and 101 women whose fetuses had normal body weights were included in the normal body weight group (normal group). Fasting venous blood samples were collected from the elbow at 28-30 wk gestation and 1-3 d before delivery to measure serum D-D and HbA1c levels for comparative analysis. The diagnostic value of serum D-D and HbA1c levels for FGR was evaluated by receiver operating characteristic analysis, and the influencing factors of third-trimester FGR in GDM patients were analyzed by logistic regression.

RESULTS

Serum fasting blood glucose, fasting insulin, D-D and HbA1c levels were significantly greater in the FGR group than in the normal group, while the homeostasis model assessment of insulin resistance values were lower (P < 0.05). Regarding the diagnosis of FGR based on serum D-D and HbA1c levels, the areas under the curves (AUCs) were 0.826 and 0.848, the cutoff values were 3.04 mg/L and 5.80%, the sensitivities were 81.0% and 79.4%, and the specificities were 88.1% and 87.1%, respectively. The AUC of serum D-D plus HbA1c levels for diagnosing FGR was 0.928, and the sensitivity and specificity were 84.1% and 91.1%, respectively. High D-D and HbA1c levels were risk factors for third-trimester FGR in GDM patients (P < 0.05).

CONCLUSION

D-D and HbA1c levels can indicate the occurrence of FGR in GDM patients in the third trimester of pregnancy to some extent, and their combination can be used as an important index for the early prediction of FGR.

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.

Development and internal validation of a clinical score to predict neonatal hypoglycaemia in women with gestational diabetes

INTRODUCTION

Gestational diabetes (GD) is a risk factor for neonatal hypoglycaemia (NH), but other factors can increase this risk.

OBJECTIVES

To create a score to predict NH in women with GD.

METHODS

Retrospective study of women with GD with a live singleton birth between 2012 and 2017 from the Portuguese GD registry. Pregnancies with and without NH were compared. A logistic regression was used to study NH predictors. Variables independently associated with NH were used to score derivation. The model's internal validation was performed by a bootstrapping. The association between the score and NH was assessed by logistic regression.

RESULTS

We studied 10216 pregnancies, 410 (4.0%) with NH. The model's AUC was 0.628 (95%CI: 0.599-0.657). Optimism-corrected c-index: 0.626. Points were assigned to variables associated with NH in proportion to the model's lowest regression coefficient: insulin-treatment 1, preeclampsia 3, preterm delivery 2, male sex 1, and small-for-gestational-age 2, or large-for-gestational-age 3. NH prevalence by score category 0-1, 2, 3, 4, and ≥5 was 2.3%, 3.0%, 4.5%, 6.0%, 7.4%, and 11.5%, respectively. Per point, the OR for NH was 1.35 (95% CI: 1.27-1.42). A score of 2, 3, 4, 5 or ≥6 (versus ≤1) had a OR for NH of 1.67 (1.29-2.15), 2.24 (1.65-3.04), 2.83 (2.02-3.98), 3.08 (1.83-5.16), and 6.84 (4.34-10.77), respectively.

CONCLUSION

Per each score point, women with GD had 35% higher risk of NH. Those with ≥6 points had 6.8-fold higher risk of NH compared to a score ≤1. Our score may be useful for identifying women at a higher risk of NH.

First-trimester HbA1c in relation to plasma glucose concentrations in an oral glucose tolerance test at 12 to 16 weeks' gestation-a population-based study

BACKGROUND

Early-onset GDM often requires pharmacological treatment and is associated with adverse perinatal outcomes, but data is insufficient regarding the best methods to identify high-risk women requiring early GDM screening. The aim of this study was to analyze the diagnostic accuracy of HbA1c in the prediction of (1) plasma glucose concentrations > 90th percentile in an oral glucose tolerance test (OGTT) at 12-16 weeks' gestation; and (2) pharmacologically treated early- or late-onset GDM.

METHODS

HbA1c was measured at 8-14 weeks' gestation in a population-based cohort of 1394 Finnish women recruited for the Early Diagnosis of Diabetes in Pregnancy (EDDIE) study between 3/2013 and 12/2016. Information on maternal risk factors were collected at recruitment. Subsequently, a 2-hour 75 g OGTT was performed at 12-16 weeks' gestation (OGTT1), and if normal, repeated at 24-28 weeks' gestation (OGTT2). Early- and late-onset GDM were diagnosed using the same nationally endorsed cut-offs for fasting, 1 h- and 2 h-plasma glucose: ≥5.3, ≥ 10.0mmol/l, and/or ≥ 8.6mmol/l, respectively. In total, 52/1394 (3.7%) women required metformin or insulin treatment for GDM, including 39 women with early-onset GDM diagnosed at OGTT1 and 13 women with late-onset GDM diagnosed at OGTT2.

RESULTS

Maternal early-pregnancy HbA1c ≥ 35mmol/mol (≥ 5.4%) was the best cut-off to predict fasting or post-load plasma glucose > 90th percentile in OGTT1, but its diagnostic accuracy was low [AUC (95% CI) 0.65 (0.62 to 0.69), sensitivity 0.55 (0.49 to 0.60) and specificity 0.67 (0.64 to 0.70)] both alone and in combination with other maternal risk factors. However, HbA1c ≥ 35mmol/mol correlated positively with plasma glucose concentrations at all time points of OGTT1 and predicted pharmacologically treated GDM diagnosed at OGTT1 or OGTT2; AUC (95% CI) 0.75 (0.68 to 0.81), sensitivity 0.75 (0.61 to 0.86), specificity 0.64 (0.61 to 0.66).

CONCLUSIONS

In our population-based cohort, early-pregnancy HbA1c ≥ 35mmol/mol was positively associated with fasting and post-load plasma glucose concentrations in an OGTT at 12-16 weeks' gestation and predicted pharmacologically-treated early- and late-onset GDM, suggesting potential utility in first-trimester identification of women at high risk of severe GDM subtypes.

Association Between Serum Glycated Hemoglobin Levels at Early Gestation and the Risk of Subsequent Pregnancy Loss in Pregnant Women Without Diabetes Mellitus: Prospective Cohort Study

BACKGROUND

As a severe morbidity during pregnancy, the etiology of spontaneous pregnancy loss (SPL) remains largely unknown. Serum glycated hemoglobin (HbA1c) level is an established predictor of SPL risk among women with diabetes, but little is known about whether such an association exists among pregnant women without diabetes when glycemic levels are within the normal range.

OBJECTIVE

This study aimed to quantify the association between maternal HbA1c levels in early pregnancy and subsequent SPL risk in a cohort of pregnant women without diabetes.

METHODS

This prospective cohort study involved 10,773 pregnant women without diabetes enrolled at their first antenatal care visit at a hospital's early pregnancy clinic from March 2016 to December 2018 in Shanghai, China. HbA1c and fasting blood glucose (FBG) levels were examined at enrollment. Participants with diabetes before or pregnancy or those diagnosed with gestational diabetes were excluded. Diagnosis of SPL, defined as fetal death occurring before 28 gestational weeks, was derived from medical records and confirmed via telephone interviews. We used generalized linear models to quantify the associations of continuous and dichotomized maternal HbA1c levels with SPL risk and reported crude and adjusted risk ratios (RRs) and 95% CIs. A restricted cubic spline (RCS) regression model was used to assess the potential nonlinear dose-response relationship. Adjusted covariates included maternal age, education level, preconception BMI, gestational weeks, gravidity, history of adverse pregnancy outcomes, family history of diabetes, folic acid supplementation, and smoking and drinking during the periconception period.

RESULTS

In total, 273 (2.5%) SPL cases occurred. Every 0.5% increase in HbA1c levels was linearly associated with a 23% increase in SPL risk (adjusted RR [aRR] 1.23; 95% CI 1.01-1.50). The RCS model revealed that this association was linear (P=.77 for the nonlinearity test). Analyses based on dichotomized HbA1c levels showed a significantly increased risk of SPL when HbA1c levels were ≥5.9% (aRR 1.67; 95% CI 0.67-3.67), and the significance threshold was ≥5.6% (aRR 1.60; 95% CI 1.01-2.54). Sensitivity analyses showed similar results when including the participants with missing SPL records or HbA1c data. Linear associations of HbA1c levels remained significant even in the subgroups without overweight, alcohol consumption, and a family history of diabetes and adverse pregnancy outcomes. Every 1 mmol/L increment in maternal FBG levels was associated with a >2-fold higher risk of SPL (aRR 2.12; 95% CI 1.61-2.80; P<.001).

CONCLUSIONS

Higher HbA1c levels in early pregnant women without diabetes are associated with an increased SPL risk in a dose-response manner. Pregnant women with an HbA1c level above 5.6% at early gestation need attention for its potentially increased risk for SPL. Our findings support the need to monitor HbA1c levels to identify individuals at high risk of subsequent SPL in the general population of pregnant women.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02737644; https://clinicaltrials.gov/study/NCT02737644.

A selective LSPR biosensor for molecular-level glycated albumin detection

A biosensor specifically engineered to detect glycated albumin (GA), a critical biomarker for diabetes monitoring, is presented. Unlike conventional GA monitoring methods, the biosensor herein uniquely employs localised surface plasmon resonance (LSPR) for signal transduction, leveraging a novel fabrication process where gold nanoparticles are deposited on a quartz substrate using flame spray pyrolysis. This enables the biosensor to provide mean glucose levels over a three-week period, correlating with the glycation status of diabetes patients. The sensor's DNA aptamer conjugation selectively binds GA, inducing a plasmonic wavelength shift; resulting in a detection limit of 0.1 μM, well within the human GA range of 20-240 μM. Selectivity experiments with diverse molecules and an exploration of sensor reusability were carried out with positive results. The novelty of the biosensor presented includes specificity, sensitivity and practical applicability; which is promising for enhanced diabetes diagnosis using a rapid and inexpensive process.

Clinical Factors for Predicting Pharmacotherapy in Twin Pregnancies Complicated by Gestational Diabetes Mellitus

Controlling blood glucose levels is the main target in pregnant women with gestational diabetes mellitus (GDM). Twin pregnancies are offered the same screening selection and have the same diagnostic criteria as well as treatment of gestational diabetes as singleton pregnancies, even though the risks for pregnancy complications are increased. The aim of this study was to assess the association between predicting factors, OGTT glucose levels and pharmacotherapy requirements in twin pregnancies with GDM. This retrospective cohort study included 446 GDM patients with twin pregnancies (246 managed with lifestyle modifications and 200 requiring pharmacotherapy) over a time period of 18 years. An evaluation of maternal characteristics and a standardized 75 g oral glucose test (OGGT) for glucose concentrations at fasting, 1 h and 2 h were conduced. OGTT glucose levels at fasting (=0 min, p < 0.01) and 1 h (p < 0.01) were significantly associated with the later requirement of pharmacotherapy. Also, clinical risk factors (pre-pregnancy BMI p < 0.01, multiparity p < 0.05, GDM in previous pregnancy p < 0.01, assisted reproduction p < 0.05) showed a predictive accuracy for insulin therapy in twin pregnancies complicated by GDM, whereas age and chorionicity had no effect. OGTT glucose measures in addition to clinical risk factors are promising variables for risk stratification in mothers with GDM and twin pregnancy.

A pre-conception clinical trial to reduce intergenerational obesity and diabetes risks: The NDPP-NextGen trial protocol

BACKGROUND

Intrauterine exposure to maternal overweight/obesity or diabetes transmits risks to offspring, perpetuating a disease cycle across generations. Prenatal interventions to reduce maternal weight or dysglycemia have limited impact, while postpartum interventions can alter the intrauterine environment only if child-bearing continues. Efficacious preconception interventions are needed, especially for underserved populations, and with the potential to be scaled up sustainably. Research is also needed to assess intervention effects at conception, throughout pregnancy, and among offspring.

METHODS

This two-arm, parallel randomized clinical trial will include 360 biological females with overweight/obesity and moderate-to-high likelihood of pregnancy within 24 months. Participants will be randomized 1:1 to a yearlong pre-conception lifestyle intervention based on the National Diabetes Prevention Program (NDPP-NextGen) or usual care. Data collection will occur at enrollment (before conception), post-conception (<8 weeks gestation), late pregnancy (28-32 weeks gestation), and delivery (before discharge) for participants who become pregnant within 24 months of enrollment. Main outcomes are post-conception body mass index (<8 weeks gestation; primary outcome), post-conception fasting glucose (<8 weeks gestation; secondary outcome), and neonatal adiposity (<2 days post-birth). Additional clinical, behavioral, perinatal and offspring data will be collected, and biospecimens (blood, urine, stool, cord blood) will be banked for future ancillary studies.

CONCLUSION

This clinical trial will evaluate an intervention model (NDPP-NextGen) with potential to improve maternal health among the >50% of US females with overweight/obesity or diabetes risks in pregnancy. If successful, it can be scaled among >1800 organizations delivering NDPP in the United States to benefit the health of future generations.

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.

A population-based longitudinal study on glycated hemoglobin levels and new-onset chronic kidney disease among non-diabetic Japanese adults

Chronic kidney disease (CKD) is a major global public health problem. Recent studies reported that diabetes and prediabetes are risk factors for developing CKD; however, the exact glycated hemoglobin (HbA1c) cut-off value for prediabetes remains controversial. In this study, we aimed to examine the relationship between HbA1c levels and subsequent CKD development in greater detail than previous studies. Longitudinal data of annual checkups of 7176 Japanese non-diabetic people (male: 40.4%) from 1998 to 2022 was analyzed. HbA1c values were categorized into < 5.0%, 5.0-5.4%, 5.5-5.9%, and 6.0-6.4%. CKD was defined as an estimated glomerular filtration rate < 60 ml/min/1.73 m2. The descriptive statistics at study entry showed that higher HbA1c values were associated with male, older, overweight or obese, hypertensive, or dyslipidemic people. During a mean follow-up of 7.75 person-years, 2374 participants (male: 40.0%) developed CKD. The Weibull accelerated failure time model was selected because the proportional hazards assumption was violated. The adjusted time ratios of developing CKD for HbA1c levels of 5.5-5.9% and 6.0-6.4% compared with 5.0-5.4% were 0.97 (95% confidence interval: 0.92-1.03) and 1.01 (95% confidence interval: 0.90-1.13), respectively. There was no association between HbA1c in the prediabetic range and subsequent CKD development.

Prepregnancy body mass index and glycated albumin in the third trimester may predict infant complications in gestational diabetes mellitus: a retrospective cohort study

Background

Maternal hyperglycemia, obesity, and hypertension with gestational diabetes mellitus (GDM) are risk factors for infant complications. This study aimed to investigate maternal factors and glycemic control indicators that affect infant complications in GDM.

Methods

We conducted a retrospective cohort study including 112 mothers with GDM and their infants. Multivariate logistic regression analysis was used to investigate the variables associated with good and adverse infant outcomes. We determined the cutoff values of variables that showed a significant difference in the multivariate logistic regression analysis for predicting infant complications by performing receiver operating characteristic curve analysis.

Results

In the multivariate logistic regression analysis, prepregnancy BMI and GA in the third trimester were significantly related to good and adverse infant outcomes (adjusted odds ratios [aORs], 1.62; 95% CIs 1.17-2.25, p = 0.003 and aORs, 2.77; 95% CIs 1.15-6.64, p = 0.022, respectively). The cutoff values for prepregnancy BMI and GA in the third trimester were 25.3 kg/m2 and 13.5%, respectively.

Conclusions

The importance of weight control before pregnancy and the usefulness of GA in the third trimester to predict infant complications were suggested in this study.

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.

Establishing Trimester-Specific Haemoglobin A1c Reference Intervals in Pregnant Women: A retrospective study of healthy South Asian women with normal pregnancy outcomes

Objectives

This study aimed to define trimester-specific haemoglobin A1c (HbA1c) reference intervals in healthy, pregnant South Asian women.

Methods

This retrospective study was conducted at St. Stephen's Hospital, Delhi, India, between January 2011 and December 2016. Healthy pregnant women were compared to a control group of healthy non-pregnant women. Pregnant participants had term deliveries of babies with appropriate gestational weights. The HbA1c levels were calculated in terms of non-parametric 2.5 and 97.5 percentiles for women in first (T1), second (T2) and third (T3) trimester groups. Statistical tests were used to obtain the normal HbA1c reference values and were considered significant when P <0.05.

Results

This study included a total of 1,357 healthy pregnant women and a control group of 67 healthy, non-pregnant women. Pregnant women had a median HbA1c of 4.8% (4-5.5%) or 32 mmol/mol (20-39 mmol/mol); non-pregnant women had a median HbA1c of 5.1% (4-5.7%) or 29 mmol/mol (20-37 mmol/mol; P <0.001). The HbA1c levels for the T1, T2 and T3 groups were 4.9% (4.1-5.5%) or 30 mmol/mol (21-37 mmol/mol), 4.8% (4.5-5.3%) or 29 mmol/mol (20-34 mmol/mol) and 4.8% (3.9-5.6%) or 29 mmol/mol (19-38 mmol/mol), respectively. The HbA1c values were significant when comparing T1 versus T2 (P <0.001), T1 versus T3 (P = 0.002) and T1 versus the non-pregnant group (P = 0.001). However, T2 versus T3 was not significant (P = 0.111).

Conclusion

Compared to non-pregnant women, HbA1c levels were lower in pregnant women, despite women in the T2 and T3 groups having a higher body mass index than the women in the T1 and non-pregnant groups. Further research is recommended to understand the factors responsible and validate these findings.

Screening test characteristics and comparison of diabetes outcomes among pregnant patients with prediabetes

This study sought to compare test characteristics of hemoglobin A1c, oral glucose tolerance test and fasting plasma glucose for the development of gestational diabetes among women with prediabetes. Diabetes outcomes were compared by screening test used for prediabetes diagnosis among a retrospective cohort of pregnant patients between 2017-2021. During the study, 8132 patients received diabetes screening and 14.0% met criteria for prediabetes. By screening test, 75.1% were screened with hemoglobin A1c, 10.0% with fasting plasma glucose and 14.9% with a 75-g oral glucose tolerance test. Hemoglobin A1c had the highest positive predictive value (67.2%). Use of hemoglobin A1c was significantly more likely to identify women with GDM than oral glucose tolerance test (aOR 3.94, 95% CI 2.30-6.73). In this study cohort, hemoglobin A1c was able to identify patients that were more likely to develop GDM in an at-risk population.IMPACT STATEMENTWhat is already known on this subject? Prediabetes is becoming more common in the general population; however little is known about prediabetes in pregnancy. Women with prediabetes in pregnancy appear to be at increased risk of developing gestational diabetes mellitus, however there is minimal information about various screening tests performance in pregnancy for detection of prediabetes and subsequent gestational diabetes.What do the results of this study add? The results of this study compare three commonly used screening tests for screening for diabetes. When identifying women with prediabetes, they are at increased risk for developing gestational diabetes mellitus if identified by hemoglobin A1c.What are the implications of these findings for clinical practice and/or further research? The clinical implication of this study is that women can be screened with hemoglobin A1c in early pregnancy for both overt diabetes, but also may be identified as high risk with prediabetes. Among women with prediabetes by hemoglobin A1c, they remain at high risk for developing gestational diabetes mellitus.

Genetic Polymorphisms in the 3'-Untranslated Regions of SMAD5, FN3KRP, and RUNX-1 Are Associated with Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) is typically defined as two or more consecutive pregnancy losses prior to 20 weeks of gestation. Although the causes of idiopathic RPL are not completely understood, vascular development and glucose concentration were reported to correlate with the pregnancy loss. The TGF-β signaling pathway which plays a significant role in pregnancy is activated by the interaction between high glucose and SMAD signaling and affects the vascular cells. SMAD5 and RUNX-1 are involved in the TGF-β signaling pathway and contribute to advanced glycation end products (AGEs) production and vascular development. FN3KRP, a newly described gene, is also associated with vascular diseases and suggested to relate to AGEs. Therefore, in the present study, we investigated associations between RPL risk and genetic polymorphisms of SMAD5, FN3KRP, and RUNX-1 in 388 women with RPL and 280 healthy control women of Korean ethnicity. Participants were genotyped using real-time polymerase chain reaction and restriction fragment length polymorphism assay to determine the frequency of SMAD5 rs10515478 C>G, FN3KRP rs1046875 G>A, and RUNX-1 rs15285 G>A polymorphisms. We found that women with RPL had lower likelihoods of the FN3KRP rs1046875 AA genotype (adjusted odds ratio (AOR), 0.553; p = 0.010) and recessive model (AOR, 0.631; p = 0.017). Furthermore, combination analysis showed that SMAD5 rs10515478 C>G and FN3KRP rs1046875 G>A mutant alleles were together associated with reduced RPL risk. These findings suggest that the FN3KRP rs1046875 G>A polymorphism has a significant role on the prevalence of RPL in Korean women. Considering that it is the first study indicating a significant association between FN3KRP and pregnancy disease, RPL, our results suggest the need for further investigation of the role of FN3KRP in pregnancy loss.

Is HbA1c in the first trimester associated with adverse outcomes among pregnant Asian Indian women without gestational diabetes?

AIMS

The aim of this study is to determine the association of elevated HbA1c in the first trimester (HbA1c-FT) with adverse events among pregnant Asian Indian women without gestational diabetes (GDM).

METHODS

This retrospective cohort study included 1618 pregnant women who delivered at a single urban tertiary care center and had HbA1c-FT estimation between January 2011 and September 2017. Those with GDM according to a 75-g OGTT after 24 gestational weeks were excluded. Multivariable logistic regression models assessed the association between elevated HbA1c-FT and adverse events.

RESULTS

At a cutoff of ≥37 mmol/mol (5.5%), HbA1c-FT was associated with preterm birth at <37 gestational weeks (adjusted odds ratio (OR) 2.10, 95% CI 1.11-3.98). There was a continuum of risk for primary caesarean delivery with higher HbA1c-FT levels (adjusted OR per 5-mmol/mol (0.5%) increase in HbA1c-FT for primary caesarean delivery: 1.27, 95% CI 1.06-1.52). In the crude analysis, gestational hypertension was associated with HbA1c-FT, but not after adjustment for confounding factors. HbA1c-FT was not associated with other adverse events (macrosomia, large for gestational age babies, or other neonatal complications).

CONCLUSIONS

Even without GDM, the results suggest an association of HbA1c-FT with preterm birth and primary caesarian delivery among Asian Indian women.

Gestational Diabetes Mellitus in Pregnant Women with Beta-Thalassemia Minor: A Matched Case-Control Study

Pregnancy in women with thalassemia minor is considered safe. However, a higher incidence of maternal and neonatal complications in women with the disorder has been reported in the literature. This study aimed to determine whether there is an increased risk of gestational diabetes mellitus (GDM) in pregnant women with beta-thalassemia minor. We conducted a retrospective matched case-control study of 230 pregnant women who delivered at the Department of Obstetrics and Feto-Maternal Medicine at the Medical University of Vienna between the years 2008 and 2020, whereof 115 women had beta-thalassemia minor. We found no significant difference in the occurrence of GDM between the case group and control group of age and BMI-matched healthy women. However, we observed a significantly lower hemoglobin (Hb) and hematocrit (Ht) level during the first, the second, and the third trimesters of pregnancy, and postpartum (all: p < 0.001) among women with beta-thalassemia minor compared to the healthy controls. Neonates of women with beta-thalassemia were more likely to experience post-natal jaundice and excessive weight loss (p < 0.001). We conclude that GDM is not more likely to occur in pregnant women with beta-thalassemia minor. However, clinicians should be made aware of the risk of adverse maternal and neonatal outcomes. Furthermore, women with beta-thalassemia minor should undergo regular laboratory screening and multidisciplinary pregnancy care.

Overt Diabetes in Pregnancy

AIMS

Overt diabetes in pregnancy is defined as hyperglycemia first recognized during pregnancy which meets the diagnostic threshold of diabetes in non-pregnant adults. This case-based narrative review aims to describe this unique condition and discuss the potential implications for its accurate diagnosis and management.

METHODS AND RESULTS

We conducted a literature search in PubMed for relevant articles published in English language up to January 2022. Women with overt diabetes have a higher risk for adverse pregnancy outcomes and postpartum diabetes, compared to their counterparts with gestational diabetes mellitus (GDM). Such women often need aggressive management, including early and prompt initiation of insulin therapy, and a close follow-up during pregnancy and in the postpartum period. Not all pregnant women with overt diabetes have persistent diabetes in the postpartum period. Early diagnosis, especially during the first trimester, and fasting plasma glucose elevation (≥ 126 mg/dl or 7 mmol/L) at the time of initial diagnosis are predictors of postpartum diabetes.

CONCLUSIONS

Both GDM and overt diabetes in pregnancy are hyperglycemic conditions first recognized during pregnancy, but the two conditions differ in severity; the latter is a more severe form of hyperglycemia associated with worse maternal and fetal outcomes, and a higher risk of postpartum diabetes.

The role of first-trimester HbA1c in the early detection of gestational diabetes

Background

We aimed to assess the utility of HbA1c in the early detection of gestational diabetes (GDM) in the first trimester.

Methods

This prospective study was performed on 700 pregnant women in the perinatology clinic at a tertiary university hospital from March 2018 to March 2020. For all pregnant women, HbA1c and fasting blood glucose (FBG) levels were examined during the first trimester. Then, a GDM screening test was done within 24–28 weeks of pregnancy using a 100 g oral glucose tolerance test (OGTT) as the gold standard test. The GDM diagnosis was made according to the American Diabetes Association (ADA) criteria. Sensitivity, specificity, positive (PPV), and negative predictive value (NPV) of HbA1c and FBG were calculated using the receiver operating characteristic (ROC) curve.

Results

Of 700 participants, one hundred and fifteen (16.4%) women had GDM. The GDM patients were significantly older and had a higher pre-gestational body mass index and pregnancy weight gain compared to the non-GDM participants. The sensitivity and specificity for ruling out GDM at an HbA1c cut-off value of 4.85% was 92.2 and 32.8%, respectively, with a 95.5% NPV and a 21.2% PPV. Furthermore, sensitivity and specificity for diagnosing GDM at an HbA1c cut-off value of 5.45% was 54.8 and 96.8%, respectively, with a 91.5% NPV and a 76.8% PPV. Using HbA1c could decline OGTT in 40.4% of the pregnant women (28.7% with HbA1c < 4.85 and 11.7% with HbA1c ≥ 5.45%).

Conclusion

It seems that the first-trimester HbA1c cannot replace OGTT for the diagnosis of GDM because of its insufficient sensitivity and specificity. However, women with higher first-trimester HbA1c had a high risk for GDM incidence.

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

Background

Maternal diabetes is a well-known risk factor for pregnancy complications. Possible links between long-term maternal blood sugar in the normal range and pregnancy complications are less well described.

Methods

We assayed glycated haemoglobin (HbA1c) in blood samples collected around the 18th week of pregnancy for 2937 singleton pregnancies in the Norwegian Mother, Father and Child Cohort Study (2000–09). Perinatal outcomes (gestational length, birthweight, birth length and head circumference, large-for-gestational age, small-for-gestational age, congenital malformations, preterm delivery and preeclampsia) were obtained from medical records. We tested associations using linear and log-binomial regression, adjusting for maternal age, body mass index (BMI) and smoking.

Results

Size at birth increased modestly but linearly with HbA1c. Birthweight rose 0.10 standard deviations [95% confidence interval (CI): 0.03, 0.16], for each 5-mmol/mol unit increase in HbA1c, corresponding to about 40 g at 40 weeks of gestation. Large-for-gestational age rose 23% (95% CI: 1%, 50%) per five-unit increase. Other pregnancy complications increased in non-linear fashion, with strongest associations within the top quartile of HbA1c (>35 mmol/mol or >5.4%). Per unit HbA1c within the top quartile, preterm delivery increased by 14% (95% CI: 1%, 31%), preeclampsia increased by 20% (95% CI: 5%, 37%) and gestational duration decreased by 0.7 days (95% CI: −1.0, −0.3).

Conclusions

Among women with no recorded diabetes, higher HbA1c levels at 18 gestational weeks were associated with important perinatal outcomes independent of mother’s age, smoking or BMI.

Early Identification of the Maternal, Placental and Fetal Dialog in Gestational Diabetes and Its Prevention

Gestational diabetes mellitus (GDM) complicates between 5 and 12% of pregnancies, with associated maternal, fetal, and neonatal complications. The ideal screening and diagnostic criteria to diagnose and treat GDM have not been established and, currently, diagnostic use with an oral glucose tolerance test occurs late in pregnancy and produces poor reproducibility. Therefore, in recent years, significant research has been undertaken to identify a first-trimester biomarker that can predict GDM later in pregnancy, enable early intervention, and reduce GDM-related adverse pregnancy outcomes. Possible biomarkers include glycemic markers (fasting glucose and hemoglobin A1c), adipocyte-derived markers (adiponectin and leptin), pregnancy-related markers (pregnancy-associated plasma protein-A and the placental growth factor), inflammatory markers (C-reactive protein and tumor necrosis factor-α), insulin resistance markers (sex hormone-binding globulin), and others. This review summarizes current data on first-trimester biomarkers, the advantages, and the limitations. Large multi-ethnic clinical trials and cost-effectiveness analyses are needed not only to build effective prediction models but also to validate their clinical use.

Real-world screening for diabetes in early pregnancy: Improved screening uptake using universal glycated haemoglobin

AIMS

To improve perinatal outcomes, screening for hyperglycaemia using 75 g oral glucose tolerance test (OGTT) is recommended for all pregnant women at 24-28 weeks gestation (routine), and earlier if high-risk. Screening coverage for remote and Aboriginal Australian women is less than ideal. This study examined OGTT completion (early and routine) by women from rural and remote Western Australia compared with early glycated haemoglobin (HbA_1c).

METHODS

In 2015-2018, 27 primary health care sites recruited 600 (233 Aboriginal) women aged ≥16-years, without pre-existing diabetes, who delivered >30-weeks gestation. All women presenting <20-weeks gestation (541) were offered an early study HbA_1c. Early OGTTs were requested at the discretion of the local clinician, with routine OGTT offered at 24-28 weeks.

RESULTS

HbA_1c uptake was high (85.7% Aboriginal, 86.4% non-Aboriginal); OGTT completion in Aboriginal women was low (early OGTT: 38.6% v 69.6% non-Aboriginal, P < 0.001; routine OGTT: 44.5% v 84.7% non-Aboriginal, P < 0.001). Aboriginal women with both early tests had HbA_1c completed 3-weeks prior to OGTT (9.6 ± 3.5 v 12.5 ± 3.5 weeks gestation, P < 0.001).

CONCLUSIONS

Universal early pregnancy HbA_1c appears feasible as an early screening test for women at risk of hyperglycaemia in pregnancy and would expedite and increase screening in Aboriginal women compared to an early OGTT.

Early Gestational Diabetes Mellitus: Diagnostic Strategies and Clinical Implications

Preexisting diabetes mellitus (DM) should be ruled out early in pregnancy in those at risk. During screening, a significant proportion of women do not reach the threshold for overt DM but fulfill the criteria used for diagnosing conventional gestational DM (cGDM). There is no consensus on the management of pregnancies with intermediate levels of hyperglycemia thus diagnosed. We have used the term early gestational DM (eGDM) for this condition and reviewed the currently available literature. Fasting plasma glucose (FPG), oral glucose tolerance test, and glycated hemoglobin (HbA1c) are the commonly employed screening tools in early pregnancy. Observational studies suggest that early pregnancy FPG and Hba1c correlate with the risk of cGDM and adverse perinatal outcomes. However, specific cut-offs, including those proposed by the International Association of the Diabetes and Pregnancy Study Group, do not reliably predict the development of cGDM. Emerging data, though indicate that FPG ≥ 92 mg/dL (5.1 mmol/L), even in the absence of cGDM, signals the risk for perinatal complication. Elevated HbA1c, especially a level ≥ 5.9%, also correlates with the risk of cGDM and worsened outcome. HbA1c as a diagnostic test is however besieged with the usual caveats that occur in pregnancy. The studies that explored the effects of intervention present conflicting results, including a possibility of fetal malnutrition and small-for-date baby in the early treatment group. Diagnostic thresholds and glycemic targets in eGDM may differ, and large multicenter randomized controlled trials are necessary to define the appropriate strategy.

Congenital malformation and hemoglobin A1c in the first trimester among Japanese women with pregestational diabetes

AIM

To investigate the incidence of major congenital malformations in Japanese women with pregestational diabetes, and to determine the cutoff value of hemoglobin A1c (HbA1c) in the first trimester associated with congenital malformations.

METHODS

This retrospective cohort study included singleton pregnancies in Japanese women with pregestational diabetes, including type 1 and type 2 diabetes, and specific types of diabetes due to other causes. The primary outcome was the incidence of major congenital malformations. The secondary outcome was the incidence of all congenital malformations. The cutoff value of HbA1c for congenital malformations was calculated using receiver operating characteristic curve analysis. The adjusted odds ratios (aOR) of major congenital malformations were calculated using multiple logistic regression analyses.

RESULTS

This study enrolled 292 patients, including 132 (45.2%) with type 1 diabetes, 156 (53.4%) with type 2 diabetes, and 4 (1.4%) with other specific types. The incidence rates of major congenital malformations and all congenital malformations were 7.2% (21/292) and 12.7% (37/292), respectively. The cutoff value of HbA1c in the first trimester for major malformations and for all congenital malformations was 6.5%. HbA1c ≥ 6.5% was significantly associated with major malformations (aOR 3.5; 95% confidence interval: 1.2-12.6; p = 0.018).

CONCLUSION

The incidence of major congenital malformations significantly increased in pregnant Japanese women with HbA1c values of 6.5% or higher. The recommended HbA1c value during the first trimester used in other countries can be applied to pregnant Japanese women.

Free thyroxine in early pregnancy is an independent negative predictor of 3rd trimester HbA1c. Odense child cohort

BACKGROUND

Lower thyroid function outside pregnancy is associated with an increased risk of type 2 diabetes mellitus. The relationship between thyroid function in early pregnancy and glucose status in 3rd trimester has not been investigated.

AIMS

To study the association between 1st trimester thyroid function and 3rd trimester glucose status.

DESIGN

In the prospective study Odense Child Cohort (OCC), 1,041 women had 1st trimester blood samples analysed for thyroid-stimulating hormone (TSH), free T4 (FT4), thyroid peroxidase antibody and HbA1c. Third trimester (week 28) fasting blood samples included plasma glucose, insulin and HbA1c. Oral glucose tolerance test (OGTT, 75 g glucose) was performed in 509 women. First trimester FT4 was dichotomized >vs. ≤ the 25th percentile (25p = 12.9 pmol/L). Homeostatic model assessment-insulin resistance (HOMA)-IR and HOMA-β were calculated.

RESULTS

Women with FT4 ≤25p had significantly higher HbA1c in 1st and 3rd trimesters and higher 3rd trimester fasting glucose, insulin, HOMA-IR and HOMA-β compared to women with FT4 >25p. In multiple regression analyses, FT4 was an independent negative predictor of 3rd trimester HbA1c. FT4 levels in 3rd and 4th quartiles (high-normal FT4 levels) showed closest inverse associations with HbA1c (p-trend <.001). TSH was not associated with 3rd trimester HbA1c.

CONCLUSION

Women with lower levels of FT4 in early pregnancy had higher HbA1c in 3rd trimester and FT4 was an independent negative predictor of 3rd trimester HbA1c.

Association of higher HbA1c within the normal range with adverse pregnancy outcomes: a cross-sectional study

OBJECTIVE

The aim of this study was to investigate the association between a relatively high HbA1c level within the normal range and the risk of adverse pregnancy outcomes.

METHODS

This retrospective cohort study was conducted between March 2018 and March 2019 at Women's Hospital, School of Medicine, Zhejiang University. Multiple logistic regression models after adjusting for plausible confounders were implemented to assess the relationships between the level of HbA1c and adverse pregnancy outcomes.

RESULTS

A total of 8585 women were included in our study. The rates of preterm birth, macrosomia and preeclampsia were 4.4% (380/8585), 5.3% (457/8585) and 1.7% (149/8585), respectively. After adjusting for potential confounding variables, an HbA1c range of 5.5-5.9% (37-41 mmol/mol) remained significantly associated with an increased risk of preterm delivery (a-OR 2.27; 95% CI, 1.50-3.43), macrosomia (a-OR 1.97; 95% CI, 1.32-2.94) and preeclampsia (a-OR 3.70; 95% CI, 2.07-6.60). GDM-negative pregnant women with an HbA1c level in the range of 5.5-5.9% (37-41 mmol/mol) had an increased risk of preterm delivery (a-OR 2.84; 95% CI, 1.71-4.71) and preeclampsia (a-OR 3.82; 95% CI, 1.81-8.04). However, GDM-positive pregnant women had an increased risk of macrosomia (a-OR 2.12; 95% CI, 1.13-3.97) and preeclampsia (a-OR 2.62; 95% CI, 1.01-6.81).

CONCLUSION

A higher HbA1c level within the normal range is an independent risk factor for preterm delivery and preeclampsia, especially among GDM-negative women. Therefore, relevant medical staff should enhance the awareness of risk and prevention to strengthen pregnancy monitoring.

Association of Normal-Range Hemoglobin A1c Value During Midpregnancy with Adverse Birth Outcomes

Background

The midpregnancy normal-range HbA1c value and adverse birth outcomes were controversial. To address this lack of data, we examined the associations between midpregnancy normal-range HbA1c value and adverse birth outcomes.

Objective

To evaluate whether an association exists between the midpregnancy normal-range HbA1c value and adverse birth outcomes.

Materials and Methods

A total of 8389 women in their midpregnancy with normal gestational HbA1c value from the Affiliated Hospital of Jining Medical University in China participated in this study from January to December 2019. Subjects were stratified on the basis of their midpregnancy HbA1c value, and multivariate logistic regression was implemented to investigate the association between different HbA1c values and adverse birth outcomes.

Results

Incidence of preterm birth, macrosomia, and large for gestational age (LGA) for 8389 subjects were 4.8%, 6.3% and 16.5%, respectively. The multivariate logistic regression model demonstrated that the risk of preterm birth (adjusted odds ratio [OR]: 1.71 and 95% confidence interval [CI]: 1.25–2.34), macrosomia (OR: 1.68 and 95% CI: 1.26–2.22), and LGA (OR: 1.53 and 95% CI: 1.28–1.83) increase for every increase of 1% maternal HbA1c. Women with a prepregnancy body mass index (BMI) of < 25 kg/m² have a stronger correlation with HbA1c values and adverse birth outcomes than women with a prepregnancy BMI of ≥25 kg/m².

Conclusion

Our results indicated that the midpregnancy normal-range HbA1c level within the normal range is associated with adverse birth outcomes. Monitoring and controlling HbA1c may reduce the risk of adverse birth outcomes.

First trimester fasting glucose and glycated haemoglobin cut-offs associated with abnormal glucose homeostasis in the post-partum reclassification in women with hyperglycaemia in pregnancy

Hyperglycaemia first detected during pregnancy is either gestational diabetes mellitus (GDM) or previous undiagnosed diabetes. We aimed to study if there were a first trimester fasting glycaemia (FTG) and a glycated haemoglobin (HbA1c) cut-off values associated with type 2 diabetes mellitus (T2DM) or abnormal glucose homeostasis (AGH) at the post-partum oral glucose tolerance test (OGTT) reclassification. We retrospectively studied a group of pregnant women from the Portuguese National Registry of GDM. Receiver-operating characteristic (ROC) curves were used to determine the best FTG and HbA1c cut-offs to predict T2DM and AGH. We studied 4068 women. The area under the ROC curves (AUC) for the association with T2DM was 0.85 (0.80-0.90) for FTG and 0.85 (0.80-0.91) for HbA1c. The best FTG cut-off for association with T2DM was 99 mg/dL: sensitivity 77.4%, specificity 74.3%, positive predictive value (PPV) 4.8%, and negative predictive value (NPV) 99.5%. The best HbA1c cut-off for association with T2DM was 5.4%: sensitivity 79.0%, specificity 80.1%, PPV 5.7%, and NPV 99.6%. The AUC for the association of FTG and HbA1c with AGH were 0.73 (0.70-0.76) and 0.71 (0.67-0.74), respectively. The best FTG cut-off for predicting AGH was 99 mg/dL: sensitivity 59.4%, specificity 76.2%, PPV 17.0%, and NPV 95.8%. The best HbA1c cut-off was 5.4%: sensitivity 48.7%, specificity 81.5%, PPV 17.8%, and NPV 95.1%. We suggest an FTG of 99 mg/dL and an HbA1c of 5.4% as the best cut-offs below which T2DM is unlikely to be present. Almost all patients with FTG < 99 mg/dL and HbA1c < 5.4% did not reclassify as T2DM. These early pregnancy cut-offs might alert the physician for the possibility of a previous undiagnosed diabetes and alert them to the importance of testing for it after delivery.

Prediabetes and pregnancy: Early pregnancy HbA1c identifies Australian Aboriginal women with high-risk of gestational diabetes mellitus and adverse perinatal outcomes

AIMS

To assess whether early pregnancy HbA_1c can predict gestational diabetes mellitus (GDM) and adverse birth outcomes in Australian women.

METHODS

Prospective study of 466 women without diabetes, aged ≥16-years at first antenatal presentation. Recruitment was from 27 primary healthcare sites in rural and remote Australia from 9-January 2015 to 31-May 2018. HbA_1c was measured with first antenatal investigations (<20-weeks gestation). Primary outcome measure was predictive value of HbA_1c for GDM, by routine 75 g oral glucose tolerance test (OGTT; ≥24-weeks gestation), and for large-for-gestational-age (LGA) newborn.

RESULTS

Of 396 (129 Aboriginal) women with routine OGTT, 28.8% had GDM (24.0% Aboriginal). HbA_1c ≥5.6% (≥38 mmol/mol) was highly predictive (71.4%, 95% CI; 47.8-88.7%) for GDM in Aboriginal women, and in the total cohort increased risk for LGA newborn (RR 2.04, 95% CI; 1.03-4.01, P = 0.040). There were clear differences between Aboriginal and non-Aboriginal women: 16.3% v 5.2% (P < 0.001) had elevated HbA_1c whereas 12.4% v 29.6% (P < 0.001) developed hyperglycemia during pregnancy.

CONCLUSIONS

Early pregnancy HbA_1c ≥5.6% (≥38 mmol/mol) identifies Aboriginal women with apparent prediabetes and elevated risk of having an LGA newborn. Universal HbA_1c at first antenatal presentation could facilitate earlier management of hyperglycemia and improved perinatal outcome in this high-risk population.

Molecular Mechanisms of Maternal Diabetes Effects on Fetal and Neonatal Surfactant

Respiratory distress is a significant contributor to newborn morbidity and mortality. An association between infants of diabetic mothers (IDMs) and respiratory distress syndrome (RDS) has been well recognized for decades. As obesity and diabetes prevalence have increased over the past several decades, more women are overweight and diabetic in the first trimester, and many more pregnant women are diagnosed with gestational diabetes. Glycemic control during pregnancy can be challenging due to the maternal need for higher caloric intake and higher insulin resistance. Surfactant is a complex molecule at the alveolar air–liquid interface that reduces surface tension. Impaired surfactant synthesis is the primary etiology of RDS. In vitro cell line studies, in vivo animal studies with diabetic rat offspring, and clinical studies suggest hyperglycemia and hyperinsulinemia can disrupt surfactant lipid and protein synthesis, causing delayed maturation in surfactant in IDMs. A better understanding of the molecular mechanisms responsible for surfactant dysfunction in IDMs may improve clinical strategies to prevent diabetes-related complications and improve neonatal outcomes.

Aspirin and pre-eclampsia prevention in women with pre-existing diabetes: a retrospective study

BACKGROUND

Aspirin is routinely prescribed in high-risk pregnancies to prevent pre-eclampsia; however, there is a paucity of data in women with pre-existing diabetes.

AIMS

To assess the efficacy and safety of aspirin in women with pre-existing diabetes in preventing pre-eclampsia.

METHODS

A retrospective review of women with pre-existing diabetes who attended antenatal clinics in a tertiary referral hospital between 2013 and 2019 was conducted. Cases were those receiving aspirin prior to 16 weeks, with pre-eclampsia as the primary outcome. The relationship between early pregnancy glycaemic control and pre-eclampsia was also assessed.

RESULTS

Of the 164 women included in the study, 45 received aspirin. There were no differences in pre-eclampsia (odds ratio (OR) 0.9 (0.3-3.0), P = 0.924) or any other measure of placental insufficiency (OR 1.7 (0.7-4.3), P = 0.243) between the aspirin and control groups after adjusting for baseline differences. Aspirin therapy was associated with an increased risk of postpartum haemorrhage (PPH) (OR 3.1 (1.1-9.1), P = 0.041). The incidence of pre-eclampsia increased stepwise according to early pregnancy HbA1c subgroups of ≤6.0% (n = 47), 6.1-7.5% (n = 57) and > 7.5% (n = 39), with rates of 0, 12.3 and 20.5% (P = 0.007) respectively.

CONCLUSIONS

The aspirin group had a higher baseline risk of pre-eclampsia and placental insufficiency, therefore the absence of difference between the groups favoured the efficacy of aspirin. PPH was highlighted as a potential complication of therapy, and early pregnancy HbA1c as a novel risk stratification tool for pre-eclampsia in women with pre-existing diabetes.

Reducing intergenerational obesity and diabetes risk

To address the intergenerational transmission of obesity and diabetes, strategies promoting the health of women of reproductive age appear to be urgently needed. In this narrative review, we summarise what has been learned from many prenatal clinical trials, discuss the emerging evidence from preconception clinical trials and highlight persistent gaps and critical future directions. Most trials tested prenatal interventions that resulted in a limited gestational weight gain of ~1 kg and reduced gestational diabetes by 20-30%. These interventions also reduced macrosomia by 20-40% but had little-to-no impact on other offspring outcomes at birth or beyond. Far fewer trials tested preconception interventions, with almost all designed to improve conception or live-birth rates in overweight or obese women with infertility rather than reduce intergenerational risks in diverse populations. Preconception trials have successfully reduced weight by 3-9 kg and improved markers of glucose homeostasis and insulin resistance by the end of the intervention but whether effects were sustained to conception is unclear. Very few studies have reported offspring outcomes at birth and beyond, with no evidence thus far of beneficial effects on offspring obesity or diabetes risks. Further efforts to develop effective and scalable strategies to reduce risk of obesity and diabetes before conception should be prioritised, especially for diverse and under-resourced populations at disparately high risk of obesity and diabetes. Future clinical trials should include interventions with high potential for dissemination, diverse populations, thorough maternal phenotyping from enrolment through to conception and pregnancy, and rigorous assessment of offspring obesity and diabetes risks from birth onwards, including into the third generation.

Epigenome-wide association study of maternal hemoglobin A1c in pregnancy and cord blood DNA methylation

Background: Gestational hyperglycemia is associated with adverse perinatal outcomes and long-term offspring metabolic programming, likely through dysregulation of DNA methylation (DNAm). Materials & methods: We tested associations between maternal HbA1c and cord blood DNAm among 412 mother-child pairs in the genetics of glucose regulation in gestation and growth (Gen3G) and implemented Mendelian randomization to infer causality. We sought replication in an independent sample from Healthy Start. Results: Higher second trimester HbA1c levels were associated with lower DNAm at cg21645848 (p = 3.9 × 10^-11) near URGCP. Mendelian randomization and replication analyses showed same direction of effect between HbA1c and DNAm at cg21645848, but did not reach statistical significance. Conclusion: We found that higher maternal glycemia reflected by HbA1c is associated with cord blood DNAm at URGCP, a gene related with inflammatory pathways.

No association between early maternal HbA1c and offspring birthweight among women without pre-existing diabetes in Greenland

Studies of the association between maternal blood glucose measured by glycated haemoglobin (HbA1c) during pregnancy and the offspring’s birthweight have been heterogeneous. The aim of this study was to examine the association between maternal HbA1c level before gestational week 20 and the offspring’s birthweight among predominantly indigenous women in Greenland. A retrospective cohort study including all women (n = 503) and their offspring delivered from September 2015 to September 2016 at Queen Ingrid’s Hospital in Nuuk was conducted. Data were obtained from the electronic medical record. Linear regression models were used to analyse the effect of maternal HbA1c on the offspring’s birthweight with adjustment and stratification for relevant confounders and effect modifiers. Birthweight increased with 3.3 g per mmol/mol increase in HbA1c. Yet, no significant association between maternal HbA1c and the offspring’s birthweight was found after adjustment for maternal age, ethnicity, residence, smoking, and parity (β = 0.058, p = 0.711). Among obese women, a borderline significant positive association (β = 0.657, p = 0.059) was found. For term newborns, this corresponded to an increase in birthweight of 31 g per mmol/mol increase in HbA1c. Based on the current study, the use of HbA1c during pregnancy to detect the risk of delivering a newborn with macrosomia is not recommended in Greenland.

Abbreviation: HbA1c: glycosylated haemoglobin; GA: gestational age; SD: standard deviation; CI: confidence interval.

Hyperglycemia recognised in early pregnancy is phenotypically type 2 diabetes mellitus not gestational diabetes mellitus: a case control study

Objective: Gestational diabetes mellitus is defined as "diabetes recognized in the second or third trimester that is not clearly overt diabetes". Evidence relating to women with hyperglycemia early in pregnancy is limited. We aimed to evaluate women diagnosed with hyperglycemia early in pregnancy (eGDM) and compared them to those with pregestational established type 2 diabetes mellitus (T2DM) and gestational diabetes diagnosed routinely at 24-28-week gestation (rtGDM) to determine if the length of exposure to hyperglycemia adversely affected outcomes.Methods: Forty consecutive women with eGDM who attended a multidisciplinary antenatal clinic were reviewed. Two separate BMI-matched control groups were identified, recognized pregestational T2DM (n = 80) and rtGDM (n = 80). Baseline demographics and outcomes were compared.Results: A higher proportion of women in the eGDM and T2DM group required insulin and the incidence of hypertensive disorders was similarly increased compared with the rtGDM group (88.6, 77.0 versus 8.1%, p < .001 and 42.5%, 37.5 versus 12.5% p < .001, respectively). The proportion of infants born small for gestational age varied (eGDM 11.1%, T2DM 13.0%, and rtGDM 2.5%, p=.049). Postpartum, 7.5% of eGDM women were diagnosed with T2DM versus 1.3% in the rtGDM group (p<.001).Conclusions: These novel data demonstrate that the length of exposure to glucose adversely affects materno-foetal outcomes independent of maternal adiposity.

Role of maternal glucose metabolism in the association between maternal BMI and neonatal size and adiposity

BACKGROUND/OBJECTIVE

One potential mechanism by which maternal obesity impacts fetal growth is through hyperglycemia below the threshold for gestational diabetes. Data regarding which measures of maternal glucose metabolism mediate this association is sparse. The objectives of this study were to (i) quantify the associations of maternal pre-pregnancy body mass index (BMI) with neonatal size and adiposity and (ii) examine the role of markers of maternal glucose metabolism as mediators in these associations.

SUBJECTS/METHODS

This is a secondary analysis of 6,379 mother-infant dyads from the Hyperglycemia and Adverse Pregnancy Outcome cohort. Markers of glucose metabolism, including plasma glucose and c-peptide values, Stumvoll first-phase estimate, modified Matsuda index, and oral disposition index were measured and calculated from an oral glucose tolerance test (OGTT) between 24- and 32-weeks' gestation. We calculated the direct effect of maternal BMI category, measured at the time of the OGTT and regressed to estimate pre-pregnancy BMI, on neonatal (1) birth weight (BW), (2) fat mass (FM), (3) % body fat (BF%), and (4) sum of skinfold thickness (sSFT). We then calculated the indirect effect of BMI category on these measures through markers of glucose metabolism.

RESULTS

Maternal BMI category was positively associated with neonatal BW, FM, BF%, and sSFT. Additionally, mothers who were overweight or obese had higher odds of delivering an infant with BW, FM, BF%, or sSFT >90th percentile. Fasting glucose and c-peptide values were the strongest mediators in the linear associations between maternal BMI category and neonatal size and adiposity.

CONCLUSIONS

Maternal overweight and obesity were associated with higher odds of neonatal BW and adiposity >90th percentile. Fasting measures of glucose metabolism were the strongest mediators of these associations, suggesting that future studies should investigate whether incorporation of these markers in pregnant women with obesity may improve prediction of neonatal size and adiposity.

Associations between glycosylated hemoglobin level at less than 24 weeks of gestation and adverse pregnancy outcomes in Japan: The Japan Environment and Children's Study (JECS)

AIMS

To investigate the associations between glycosylated hemoglobin (HbA1c) levels at less than 24 weeks of gestation and adverse pregnancy outcomes in Japan.

METHODS

This was a prospective nationwide birth cohort study of 77,526 subjects with an HbA1c level of <6.5% (<48 mmol/mol) at less than 24 weeks of gestation. Associations of HbA1c level with adverse pregnancy outcomes were evaluated using multivariate analyses.

RESULTS

The adjusted odds ratios per 1% (11 mmol/mol) increase in HbA1c level were 1.77 (95% confidence interval [CI]: 1.48-2.12) for hypertensive disorders of pregnancy; 1.78 (95% CI: 1.12-2.83) for placental abruption; 1.30 (95% CI: 1.12-1.50) for preterm birth; 2.11 (95% CI: 1.41-3.16) for very preterm birth; 1.49 (95% CI: 1.33-1.68) for low birth weight infants; 1.95 (95% CI: 1.42-2.70) for macrosomia; 1.23 (95% CI: 1.09-1.39) for small for gestational age; 1.15 (95% CI: 1.04-1.28) for large for gestational age; and 1.29 (95% CI: 1.20-1.39) for the composite adverse pregnancy outcome.

CONCLUSIONS

The higher the HbA1c level, the higher the risk of adverse pregnancy outcomes in Japan. Further studies will be needed to determine prenatal management based on the HbA1c level in pregnant women with HbA1c <6.5% (<48 mmol/mol) at less than 24 weeks of gestation.

HbA1c during early pregnancy reflects beta-cell dysfunction in women developing GDM

INTRODUCTION

It is of current interest to assess eligibility of hemoglobin A1c (HbA1c) as a screening tool for earlier identification of women with risk for more severe hyperglycemia in pregnancy but data regarding accuracy are controversial. We aimed to evaluate if HbA1c mirrors pathophysiological precursors of glucose intolerance in early pregnancy that characterize women who develop gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

220 pregnant women underwent an HbA1c measurement as well as an oral glucose tolerance test (OGTT) with multiple measurements of glucose, insulin and C-peptide for evaluation of insulin sensitivity and beta-cell function at 16th gestational week (IQR: 14-18). Clinical follow-ups were performed until end of pregnancy.

RESULTS

Increased maternal HbA1c ≥5.7% (39 mmol/mol) corresponding to pre-diabetes outside of pregnancy was associated with altered glucose dynamics during the OGTT. Pregnancies with early HbA1c ≥5.7% showed higher fasting (90.4±13.2 vs 79.7±7.2 mg/dL, p<0.001), mean (145.6±31.4 vs 116.2±21.4 mg/dL, p<0.001) as well as maximum glucose concentrations and tended to a delay in reaching the maximum glucose level compared with those with normal-range HbA1c (186.5±42.6 vs 147.8±30.1 mg/dL, p<0.001). Women with increased HbA1c showed impaired beta-cell function and differences in disposition index independent of body mass index status. We observed a high specificity for the HbA1c cut-off of 5.7% for GDM manifestation (0.96, 95% CI 0.91 to 0.98) or need of glucose-lowering medication (0.95, 95% CI 0.90 to 0.98) although overall predictive accuracy was moderate to fair. Further, elevated HbA1c was associated with higher risk for delivering large-for-gestational-age infants, also after adjustment for GDM status (OR 4.4, 95% CI 1.2 to 15.0, p=0.018).

CONCLUSIONS

HbA1c measured before recommended routine screening period reflects early pathophysiological derangements in beta-cell function and glucose disposal that are characteristic of GDM development and may be useful in early risk stratification.

Associations of Arginine with Gestational Diabetes Mellitus in a Follow-Up Study

In the reported study we applied the targeted metabolomic profiling employing high pressure liquid chromatography coupled with triple quadrupole tandem mass spectrometry (HPLC–MS/MS) to understand the pathophysiology of gestational diabetes mellitus (GDM), early identification of women who are at risk of developing GDM, and the differences in recovery postpartum between these women and normoglycemic women. We profiled the peripheral blood from patients during the second trimester of pregnancy and three months, and one year postpartum. In the GDM group Arg, Gln, His, Met, Phe and Ser were downregulated with statistical significance in comparison to normoglycemic (NGT) women. From the analysis of the association of all amino acid profiles of GDM and NGT women, several statistical models predicting diabetic status were formulated and compared with the literature, with the arginine-based model as the most promising of the screened ones (area under the curve (AUC) = 0.749). Our research results have shed light on the critical role of arginine in the development of GDM and may help in precisely distinguishing between GDM and NGT and earlier detection of GDM but also in predicting women with the increased type 2 diabetes mellitus (T2DM) risk.

The Oral Glucose Tolerance Test: 100 Years Later

For over 100 years, the oral glucose tolerance test (OGTT) has been the cornerstone for detecting prediabetes and type 2 diabetes (T2DM). In recent decades, controversies have arisen identifying internationally acceptable cut points using fasting plasma glucose (FPG), 2-h post-load glucose (2-h PG), and/or HbA1c for defining intermediate hyperglycemia (prediabetes). Despite this, there has been a steadfast global consensus of the 2-h PG for defining dysglycemic states during the OGTT. This article reviews the history of the OGTT and recent advances in its application, including the glucose challenge test and mathematical modeling for determining the shape of the glucose curve. Pitfalls of the FPG, 2-h PG during the OGTT, and HbA1c are considered as well. Finally, the associations between the 30-minute and 1-hour plasma glucose (1-h PG) levels derived from the OGTT and incidence of diabetes and its complications will be reviewed. The considerable evidence base supports modifying current screening and diagnostic recommendations with the use of the 1-h PG. Measurement of the 1-h PG level could increase the likelihood of identifying high-risk individuals when the pancreatic ß-cell function is substantially more intact with the added practical advantage of potentially replacing the conventional 2-h OGTT making it more acceptable in the clinical setting.

Diagnostic accuracy of glycated hemoglobin for gestational diabetes mellitus: a systematic review and meta-analysis

Background We conducted a systematic review and meta-analysis to establish the overall accuracy of glycated hemoglobin (HbA1c) in the diagnosis of gestational diabetes mellitus (GDM) diagnosis. Methods We searched MEDLINE, EMBASE, SCOPUS and ClinicalTrials.gov up to October 2018, using keywords related to GDM, HbA1c and diagnosis. Studies were included that were carried out with pregnant women without previous diabetes that assessed the performance of HbA1c (index test) compared to the 75 g oral glucose tolerance test (OGTT) (reference test) for the diagnosis of GDM, that measured HbA1c by standardized methods and presented data necessary for drawing 2 × 2 tables. Results This meta-analysis included eight studies, totaling 6406 pregnant women, of those 1044 had GDM. The diagnostic accuracy of HbA1c was reported at different thresholds ranging from 5.4% (36 mmol/mol) to 6.0% (42 mmol/mol), and the area under the curve (AUC) was 0.825 (95% confidence interval [CI] 0.751-0.899), indicating a good level of overall accuracy. The pooled sensitivities and specificities were 50.3% (95% CI 24.8%-75.7%) and 83.7% (67.5%-92.7%); 24.7% (10.3%-48.5%) and 95.5% (85.7%-98.7%); 10.8% (5.7%-19.41%) and 98.7% (96.2%-99.5%); 12.9% (5.5%-27.5%) and 98.7% (97.6%-99.3%), for the cut-offs of 5.4% (36 mmol/mol), 5.7% (39 mmol/mol), 5.8% (40 mmol/mol) and 6.0% (42 mmol/mol), respectively. Conclusions We observed a high heterogeneity among the studies. The effect of ethnicities, different criteria for OGTT interpretation and the individual performance of HbA1c methods may have contributed to this heterogeneity. The HbA1c test presents high specificity but low sensitivity regardless of the threshold used to diagnose GDM. These findings point to the usefulness of HbA1c as a rule-in test. HbA1c should be used in association with other standard diagnostic tests for GDM diagnosis.

Association Between Maternal Normal Range HbA1c Values and Adverse Birth Outcomes

CONTEXT

Higher blood glucose level during gestational periods has been consistently associated with increased risk of adverse birth outcomes. Evidence regarding the association between higher glycated hemoglobin A1c (HbA1c) within the normal range and adverse birth outcomes is limited.

OBJECTIVE

We aimed to examine the association between HbA1c within the normal range and the risk of adverse birth outcomes.

DESIGN AND SETTING

The data were abstracted from the Information System of Guangdong Women and Children Hospital, China, from September 2014 to March 2018.

PATIENTS

A total of 5658 pregnant women with normal gestational HbA1c were included in this analysis.

MAIN OUTCOME MEASURES

The adverse birth outcomes include preterm birth, macrosomia, and large for gestational age (LGA).

RESULTS

Among 5658 subjects, the rates of preterm birth, macrosomia, and LGA were 4.6% (261/5658), 3.5% (200/5658), and 5.7% (325/5658), respectively. The results of multivariate logistic regression model showed that each 1% increase in maternal HbA1c was positively associated with increased risks of preterm birth (OR 1.58; 95% CI, 1.08-2.31), macrosomia (OR 1.70; 95% CI, 1.10-2.64), and LGA (OR 1.38; 95% CI, 0.98-1.96). The association between gestational HbA1c and preterm birth was more evident among women with prepregnancy body mass index (BMI) ≤ 24 kg/m2.

CONCLUSIONS

Gestational higher HbA1c level within the normal range is an independent risk factor for preterm birth, macrosomia, and LGA. Intervention for reducing HbAc1 may help to prevent adverse birth outcomes.

Longitudinal Changes in the Relationship Between Hemoglobin A1c and Glucose Tolerance Across Pregnancy and Postpartum

OBJECTIVE

To characterize the relationship between hemoglobin A1c (HbA1c) levels and glucose tolerance across pregnancy and postpartum.

DESIGN AND PARTICIPANTS

In a longitudinal study of pregnant women with gestational diabetes risk factors (N = 102), we performed oral glucose tolerance testing (OGTT) and HbA1c measurements at 10-15 weeks of gestation, 24-30 weeks of gestation (N = 73), and 6-24 weeks postpartum (N = 42). Complete blood counts were obtained from clinical records. We calculated HbA1c-estimated average glucose levels and compared them with mean OGTT glucose levels (average of fasting, 1- and 2-hour glucose levels). Linear mixed effects models were used to test for longitudinal changes in measurements.

RESULTS

Mean OGTT glucose increased between 10-15 and 24-30 weeks of gestation (β = 8.1 mg/dL, P = .001), while HbA1c decreased during the same time period (β = -0.13%, P < .001). At 10-15 weeks of gestation and postpartum the discrepancy between mean OGTT glucose and HbA1c-estimated average glucose was minimal (mean [standard deviation]: 1.2 [20.5] mg/dL and 0.16 [18.1] mg/dL). At 24-30 weeks of gestation, the discrepancy widened (13.2 [17.9] mg/dL, β = 12.7 mg/dL, P < .001, compared to 10-15 weeks of gestation, with mean OGTT glucose being higher than HbA1c-estimated average glucose). Lower hemoglobin at 24-30 weeks of gestation was associated with a greater discrepancy (β = 6.4 mg/dL per 1 g/dL lower hemoglobin, P = .03 in an age- and gestational age-adjusted linear regression model).

CONCLUSIONS

HbA1c accurately reflects glycemia in the 1st trimester, but underestimates glucose intolerance in the late 2nd trimester. Lower hemoglobin level is associated with greater underestimation. Accounting for gestational age and maternal hemoglobin may improve the clinical interpretation of HbA1c levels during pregnancy.

Risk of severe maternal morbidity or death in relation to elevated hemoglobin A1c preconception, and in early pregnancy: A population-based cohort study

BACKGROUND

The relation between prepregnancy average glucose concentration and a woman's risk of severe maternal morbidity (SMM) is unknown. The current study evaluated whether an elevated preconception hemoglobin A1c (A1c) is associated with SMM or maternal death among women with and without known prepregnancy diabetes mellitus (DM).

METHODS AND FINDINGS

A population-based cohort study was completed in Ontario, Canada, where there is universal healthcare. The main cohort included 31,225 women aged 16-50 years with a hospital live birth or stillbirth from 2007 to 2015, and who had an A1c measured within 90 days before conception, including 28,075 women (90%) without known prepregnancy DM. The main outcome was SMM or maternal mortality from 23 weeks' gestation up to 42 days postpartum. Relative risks (RRs) were generated using modified Poisson regression, adjusting for the main covariates of maternal age, multifetal pregnancy, world region of origin, and tobacco/drug dependence. The mean maternal age was 31.1 years. Overall, SMM or death arose among 682 births (2.2%). The RR of SMM or death was 1.16 (95% CI 1.14-1.19; p < 0.001) per 0.5% increase in A1c and 1.16 (95% CI 1.13-1.18; p < 0.001) after adjusting for the main covariates. The adjusted relative risk (aRR) was increased among those with (1.11, 95% CI 1.07-1.14; p < 0.001) and without (1.15, 95% CI 1.02-1.29; p < 0.001) known prepregnancy diabetes, and upon further adjusting for body mass index (BMI) (1.15, 95% CI 1.11-1.20; p < 0.001), or chronic hypertension and prepregnancy serum creatinine (1.11, 95% CI 1.04-1.18; p = 0.002). The aRR of SMM or death was 1.31 (95% CI 1.06-1.62; p = 0.01) in those with a preconception A1c of 5.8%-6.4%, and 2.84 (95% CI 2.31-3.49; p < 0.001) at an A1c > 6.4%, each relative to an A1c < 5.8%. Among those without previously recognized prepregnancy diabetes and whose A1c was >6.4%, the aRR of SMM or death was 3.25 (95% CI 1.76-6.00; p < 0.001). Study limitations include that selection bias may have incorporated less healthy women tested for A1c, and BMI was unknown for many women.

CONCLUSIONS

Our findings indicate that women with an elevated A1c preconception may be at higher risk of SMM or death in pregnancy or postpartum, including those without known prepregnancy DM.

Hyperglycaemia and factors associated with dental caries in immediate postpartum women

Objective: Dental caries and hyperglycaemia share common risk factors. The aim of this study was to identify factors associated with dental caries in women in the immediate postpartum period. It also verified whether women with hyperglycaemia presented more dental caries than those with normal glycaemia.Material and Methods: This cross-sectional study was performed on 297 women recruited from a teaching hospital in Brazil (from October 2011 to November 2012). Dental caries and oral biofilm were evaluated by oral examination. The blood glucose was accessed by Haemoglobin A1c test. Information on socioeconomic characteristics, harmful habits and oral health habits was also gathered.Results: More than half (66%) of the women had carious lesions. Univariate analysis showed no association between hyperglycaemia and dental caries (p = .39). The hierarchical logistic regression model showed that the following variables were associated with dental caries: maternal education level ≤8 years (ORadjusted = 2.40 [CI 1.19-4.82]), previous children (OR_adjusted = 1.81 [CI 1.08-3.03), use of dental floss (OR_adjusted = .48 [CI 0.27-0.86]), and visible plaque index ≥30% (OR_adjusted = 1.83 [CI 1.05-3.20]).Conclusions: These findings call attention to the need to implement effective public policies directed at avoiding tooth decay in pregnancy and in the postpartum period.

Potentially modifiable predictors of adverse neonatal and maternal outcomes in pregnancies with gestational diabetes mellitus: can they help for future risk stratification and risk-adapted patient care?

BACKGROUND

Gestational diabetes mellitus (GDM) exposes mothers and their offspring to short and long-term complications. The objective of this study was to identify the importance of potentially modifiable predictors of adverse outcomes in pregnancies with GDM. We also aimed to assess the relationship between maternal predictors and pregnancy outcomes depending on HbA1c values and to provide a risk stratification for adverse pregnancy outcomes according to the prepregnancy BMI (Body mass index) and HbA1c at the 1st booking.

METHODS

This prospective study included 576 patients with GDM. Predictors were prepregnancy BMI, gestational weight gain (GWG), excessive weight gain, fasting, 1 and 2-h glucose values after the 75 g oral glucose challenge test (oGTT), HbA1c at the 1st GDM booking and at the end of pregnancy and maternal treatment requirement. Maternal and neonatal outcomes such as cesarean section, macrosomia, large and small for gestational age (LGA, SGA), neonatal hypoglycemia, prematurity, hospitalization in the neonatal unit and Apgar score at 5 min < 7 were evaluated. Univariate and multivariate regression analyses and probability analyses were performed.

RESULTS

One-hour glucose after oGTT and prepregnancy BMI were correlated with cesarean section. GWG and HbA1c at the end pregnancy were associated with macrosomia and LGA, while prepregnancy BMI was inversely associated with SGA. The requirement for maternal treatment was correlated with neonatal hypoglycemia, and HbA1c at the end of pregnancy with prematurity (all p < 0.05). The correlations between predictors and pregnancy complications were exclusively observed when HbA1c was ≥5.5% (37 mmol/mol). In women with prepregnancy BMI ≥ 25 kg/m2 and HbA1c ≥ 5.5% (37 mmol/mol) at the 1st booking, the risk for cesarean section and LGA was nearly doubled compared to women with BMI with < 25 kg/m2 and HbA1c <  5.5% (37 mmol/mol).

CONCLUSIONS

Prepregnancy BMI, GWG, maternal treatment requirement and HbA1c at the end of pregnancy can predict adverse pregnancy outcomes in women with GDM, particularly when HbA1c is ≥5.5% (37 mmol/mol). Stratification based on prepregnancy BMI and HbA1c at the 1st booking may allow for future risk-adapted care in these patients.

Early Assessment of the Risk for Gestational Diabetes Mellitus: Can Fasting Parameters of Glucose Metabolism Contribute to Risk Prediction?

BACKGROUND

An early identification of the risk groups might be beneficial in reducing morbidities in patients with gestational diabetes mellitus (GDM). Therefore, this study aimed to assess the biochemical predictors of glycemic conditions, in addition to fasting indices of glucose disposal, to predict the development of GDM in later stage and the need of glucose-lowering medication.

METHODS

A total of 574 pregnant females (103 with GDM and 471 with normal glucose tolerance [NGT]) were included. A metabolic characterization was performed before 15⁺⁶ weeks of gestation by assessing fasting plasma glucose (FPG), fasting insulin (FI), fasting C-peptide (FCP), and glycosylated hemoglobin (HbA1c). Thereafter, the patients were followed-up until the delivery.

RESULTS

Females with NGT had lower levels of FPG, FI, FCP, or HbA1c at the early stage of pregnancy, and therefore, showed an improved insulin action as compared to that in females who developed GDM. Higher fasting levels of FPG and FCP were associated with a higher risk of developing GDM. Moreover, the predictive accuracy of this metabolic profiling was also good to distinguish the patients who required glucose-lowering medications. Indices of glucose disposal based on C-peptide improved the predictive accuracy compared to that based on insulin. A modified quantitative insulin sensitivity check index (QUICKIc) showed the best differentiation in terms of predicting GDM (area under the receiver operating characteristics curve [ROC-AUC], 72.1%) or need for pharmacotherapy (ROC-AUC, 83.7%).

CONCLUSION

Fasting measurements of glucose and C-peptide as well as the surrogate indices of glycemic condition could be used for stratifying pregnant females with higher risk of GDM at the beginning of pregnancy.