Counterpoint: Establishing consensus in the diagnosis of GDM following the HAPO study

Association between gestational abnormal glucose tolerance and maternal-fetal outcomes

AIM

To investigate the relationship between abnormal glucose tolerance during pregnancy and maternal-fetal outcomes, after categorizing women into groups with different levels of gestational abnormal glucose tolerance.

METHODS

A total of 1858 pregnant women who received two-step screening for gestational diabetes mellitus (GDM) at Fooyin University Hospital were categorized into four groups, according to their glucose abnormalities, and their maternal-fetal outcomes were investigated from October 2015 to June 2020.

RESULTS

Among the groups having different levels of abnormal glucose tolerance, there were significant differences and trends in mother's age, currently married status, and prepregnancy overweight or obesity, incidences of cesarean section, preterm, and gestational hypertension or preeclampsia; and with respect to neonatal incidence of large for gestational age (LGA), average weight, and average height (p < 0.05). After adjusting for potential factors, there were higher incidences of cesarean section (AOR = 1.71; 95% confidence interval [CI]: 1.12-2.61), preterm (AOR = 2.20; 95% CI: 1.23-3.91), neonatal LGA (AOR = 4.94; 95% CI: 2.87-8.51), and neonatal intensive care unit (NICU) admission (AOR = 2.66; 95% CI: 1.14-6.24) in the GDM group, relative to the control group. Furthermore, the women in the oral glucose tolerance test (OGTT)-1 group had a higher incidence of neonatal LGA when compared with the women in the normal group (AOR = 2.31; 95% CI: 1.02-5.33).

CONCLUSIONS

We found higher incidences of cesarean section, preterm, and neonatal LGA and NICU admission in the GDM women, and a higher incidence of neonatal LGA in the OGTT-1 group, relative to control group.

Third Trimester Myocardial Performance Index in Fetuses from Women with Hyperglycemia in Pregnancy: A Systematic Review and Meta-Analysis

INTRODUCTION

 The myocardial performance index (MPI) has been proposed to evaluate cardiac dysfunction in newborns from diabetic mothers. Although MPI is routinely assessed in newborns, its role in the evaluation of fetuses from women with hyperglycemia in pregnancy (HIP) is still under evaluation. We aimed to evaluate the differences in third trimester fetal MPI in pregnant women with hyperglycemia compared to healthy controls.

MATERIALS AND METHODS

 Seven electronic databases were searched for all studies assessing women with HIP who underwent evaluation of fetal left MPI during pregnancy compared to a control group. The summary measures were reported as mean differences (MD) in the mean fetal left MPI between women with HIP and healthy controls, with a 95 % confidence interval (CI). A post hoc subgroup analysis based on the type of HIP - pregestational diabetes, GDM, or gestational impaired glucose tolerance (GIGT) - was performed as an additional analysis.

RESULTS

 14 studies assessing 1326 fetuses (580 from women with HIP and 746 from controls) were included. Women with HIP had a significantly higher mean left fetal MPI compared to controls (MD 0.08; 95 %CI: 0.05 to 0.11; p < 0.00 001). Subgroup analysis according to the type of HIP concurred with the overall analysis for women with DM (MD 0.07; 95 %CI: 0.01 to 0.13; p = 0.02) and for women with GDM (MD 0.012; 95 %CI: 0.07 to 0.17; p < 0.00 001) but not for women with GIGT (MD -0.01, 95 % CI -0.28 to 0.27; p = 0.96).

CONCLUSION

 Fetal left MPI is increased in pregnancies with HIP appearing as a potential marker of cardiac dysfunction.

Impact of Maternal HbA1c Levels ≤6% and Race in Nondiabetic Pregnancies on Birthweight and Early Neonatal Hypoglycemia

OBJECTIVE

To evaluate whether pregnancy glycated hemoglobin (HbA1c) levels of ≤6% and maternal race impacts neonatal hypoglycemia and birthweight, and whether diabetes and beta blocker use during pregnancy additively impacts neonatal outcomes.

STUDY DESIGN

Retrospective chart review of 4769 infants born at ≥34 weeks; 21 482 glucose measurements were assessed. Predefined groups were infants born to mothers without documented pregnancy conditions (group N), prenatal exposure of beta blockers (group B), diabetes (group D), or both (group DB).

RESULTS

In group N, both in Caucasian (Caucasian, n = 1756; β = 2.6, P < .001) and African American (n = 1872; β = 2.2, P = .002) race, there was a direct relationship between pregnancy HbA1c levels and birthweight. HbA1c (aOR 1.8; 95% CI [1.3-2.5]) levels, maternal race, prematurity, cesarean delivery, and birth weight predicted hypoglycemia. Each 0.1% increase in HbA1c levels between 4.8 and 6 increased the odds of neonatal hypoglycemia by 6.4% in African American (β 0.62, SE 0.22, P = .01) and by 12.0% in Caucasian (β 1.13, SE 0.23 P < .001) population. The odds of neonatal hypoglycemia were 1.7 (group B), 2.1 (group D), and 3.1 (group DB) times higher compared with group N.

CONCLUSIONS

Pregnancy HbA1c levels between 4.8% and 6.0% considered acceptable during pregnancy impacts neonatal hypoglycemia and birthweight especially in Caucasian race. A third trimester HbA1c >5.2 is a potential risk factor for neonatal hypoglycemia, especially in preterm infants. Although we report new findings on the relationship between maternal HbA1c levels and neonatal outcomes, a prospective study is required to validate our findings and determine "optimal" HbA1C levels during pregnancy.

Implementing the 2013 WHO diagnostic criteria for gestational diabetes mellitus in a Rural Nigerian Population

Introduction

the World Health Organization (WHO) reviewed the threshold values required for the diagnosis of Gestational Diabetes Mellitus (GDM) in 2013 and the implementation of the new diagnostic criteria have been associated with increase in the prevalence of GDM in some populations. The new cohort of pregnant women that will be labeled to have GDM by the 2013 WHO diagnostic criteria but not by the 1999 WHO diagnostic criteria will pose additional burden to specialized antenatal care, though their pregnancy outcome may not warrant such care. It is thus important to first determine the effect of the implementation of these new consensus diagnostic criteria on the prevalence of GDM in our environment.

Methods

this is a prospective hospital-based study that compared the implementation of both 1999 and 2013 WHO GDM diagnostic criteria among 117 pregnant women who were initially screened with 50-gram Glucose Challenge Test (50-g GCT). Women with a positive Glucose Challenge Test (GCT) result underwent a 75-gram Oral Glucose Tolerance Test (75-g OGTT), which was used as the actual diagnostic test for GDM using both 2013 WHO and 1999 WHO diagnostic criteria. Associations between variables were tested using Chi-square, Fisher's exact and t-test as appropriate. Significance level was set at P value < 0.05.

Results

the prevalence rates of GDM in the study were 2.6% and 7.7% for 1999 WHO and 2013 WHO criteria respectively. Clinical characteristics were similar in women with GDM and women without GDM. The fasting component of the OGTT identified all the women with GDM.

Conclusion

the implementation of the 2013 WHO diagnostic criteria is associated with a 2.5 to 3-fold rise in the prevalence of GDM. Selective risk-factor based screening may be clinically irrelevant with the adoption of the 2013 WHO diagnostic criteria. A minimum of fasting plasma glucose in resource poor settings can be considered to identify women with GDM since it appeared to have 100% sensitivity in our study.

Gestational Diabetes Mellitus Screening and Diagnosis

An ideal screening test for gestational diabetes should be capable of identifying not only women with the disease but also the women with a high risk of developing gestational diabetes mellitus (GDM). Screening and diagnosis are the main steps leading to the way of management. There is a lack of consensus among healthcare professionals regarding the screening methods worldwide. Different study groups advocate a variety of screening methods with the support of evidence-based comprehensive data. Some of the organizations suggest screening for high risk or all pregnant women, while others prefer to offer definitive testing without screening. Glycemic thresholds are also not standardized to decide GDM among different guidelines. Prevalence rates of GDM vary between populations and with the choice of glucose thresholds for both screening and definitive tests. One-step or two-step methods have been used for GDM diagnosis. However, screening includes selecting patients with historical risk factors, 50 g 1-h glucose challenge test, fasting plasma glucose, random plasma glucose, and hemoglobin A1c with different cutoffs. In this chapter, screening and diagnosis methods of GDM accepted by different study groups will be discussed which will be followed by the evaluation of different glycemic thresholds. Then the advantages and disadvantages of used methods will be explained and the chapter will finish with an evaluation of the current international guidelines.

Performance of Variables in Screening for Gestational Diabetes

Introduction: Gestational diabetes mellitus (GDM) is associated with adverse pregnancy outcomes. The strategies used to screen for GDM vary both internationally and nationally. Therefore, we investigated the performance of the capillary random plasma glucose (RPG) test, maternal body mass index (BMI) and maternal age in predicting GDM. Methods: In a retrospective cohort study, we included pregnant women without pre-existing diabetes or metabolic disease who gave birth in Västernorrland County, Sweden, in 2015–2016. Values for RPG in gestational weeks 23–28 were obtained from obstetric medical records for each pregnancy. The development of GDM was confirmed by evaluating data in the obstetric records. The ability of RPG, maternal BMI, and age to predict GDM was assessed with receiver-operating characteristic curves. Results: In total, 4,698 pregnancies were included in the final statistical analysis. RPG was fairly effective in screening (area under the curve [AUC] 0.73; 95% confidence interval [CI] 0.66–0.80), and BMI performed slightly better (AUC 0.75; 95% CI 0.68–0.82), whereas maternal age performed poorly (AUC 0.61; 95% CI 0.53–0.68). Combining RPG ≥7 and BMI ≥27.9 yielded the best overall sensitivity (75.4%), specificity (70.1%), and AUC (0.75; 95% CI 0.68–0.82). Conclusions: Our results show that the sensitivity of capillary RPG alone in predicting GDM is fair. The combination of RPG with maternal BMI or age showed greater sensitivity. However, none of the screening factors (RPG, BMI, and maternal age), alone or combined, showed sufficiently good performance in predicting GDM.

Placental exosomes viewed from an 'omics' perspective: implications for gestational diabetes biomarkers identification

Exosomes are defined as extracellular vesicles that are released from cells upon fusion of an intermediate endocytic compartment - the multivesicular body - with the plasma membrane. Recently, placenta-derived exosomes have gained special attention, since they play a crucial role in the communication between the mother and fetus. It is known that the concentration of placenta-derived exosomes in the maternal bloodstream is higher in patients with preeclampsia or gestational diabetes mellitus. However, their composition in terms of the content of proteins, nucleic acids or lipids is uncertain. In this work, we reviewed the recent advances in placental exosomes characterization through omics-based methods, and their potential to predict gestational diabetes mellitus.

The post-HAPO situation with gestational diabetes: the bright and dark sides

AIM

In 2010, in light of the data coming from the HAPO study, the International Association of Diabetes and Pregnancy Study Groups (IADPSG) proposed a new detection strategy and diagnostic criteria for gestational diabetes based on a one-step approach with a 75 g OGTT. This review analyzes and discusses the bright and dark sides of their application.

METHODS

The assessment of these recommendations by the international organizations involved in the care of gestational diabetes and a series of observational, retrospective and prospective studies that have been published since 2010 regarding the use of the IADPSG recommendations have been evaluated.

RESULTS

The different international associations involved in the care of pregnancy and of pregnancy complicated by diabetes have not taken an univocal position some of which have accepted them, while others have criticized them. Then, the actual application of the approach recommended by the IADPSG for detecting and diagnosing GDM varies, even at centers that reportedly accept the new diagnostic criteria.

CONCLUSION

So the challenge lies in making every effort to achieve a global standardization of the strategies for detecting, diagnosing and treating GDM.

Predictive factors for birth weight of newborns of mothers with gestational diabetes mellitus

AIMS

To evaluate the predictive factors of birth weight (BW) of newborns of women with gestational diabetes mellitus (GDM).

METHODS

A cross-sectional study was performed among pregnant women with GDM treated in a public maternity unit, Brazil. We selected 283 pregnant women, with nutritional follow-up initiated till the 28th gestational week, singleton pregnancy, without chronic diseases and with birth weight information of the newborns. The predictive factors of BW were identified by multivariate linear regression.

RESULTS

Mean maternal age was 31.2 ± 5.8 years; 64.4% were non-white; 70.1% were pre-gestational overweight or obese. Mean BW was 3234.3 ± 478.8 g. An increase of 1 kg of weight in the first and third trimesters increased BW by 21 g (p = 0.01) and 27 g (p = 0.03), respectively. Similarly, the other predictive factors of BW were pre-gestational body mass index (β = 17.16, p = 0.02) and postprandial plasma glucose in the third trimester (β = 4.14, p = 0.008), in the model adjusted by gestational age at delivery (β = 194.68, p < 0.001).

CONCLUSIONS

The best predictors of BW were gestational age at birth, and maternal pre-gestational and gestational anthropometric characteristics. Maternal glycaemic levels may also influence BW. The results may contribute to a review of prenatal routines for pregnant women with GDM.

Metabolomics of Diabetes in Pregnancy

PURPOSE OF REVIEW

The purpose of this review is to describe ways in which metabolomics may enhance understanding of gestational diabetes mellitus (GDM) etiology and refine current diagnostic criteria.

RECENT FINDINGS

Current clinical recommendations suggest screening for GDM between 24 and 28 of gestational weeks using an oral glucose tolerance test. Despite this consensus, there are discrepancies regarding the exact criteria for GDM diagnosis. Further, emerging evidence has unveiled heterogeneous physiological pathways underlying GDM-specifically, GDM with defective insulin secretion vs. sensitivity-that have important implications for disease diagnosis and management. The objectives of this review are threefold. First, we seek to provide a brief summary of current knowledge regarding GDM pathophysiology. Next, we describe the potential role of metabolomics to refine and improve the prediction, screening, and diagnosis of GDM. Finally, we propose ways in which metabolomics may eventually impact clinical care and risk assessment for GDM and its comorbidities.

Italian national guidelines for the screening of gestational diabetes: Time for a critical appraisal?

BACKGROUND AND AIM

In 2011, the Italian National Health System guidelines introduced a selective screening for gestational diabetes (GDM) based on risk factors, recommending early evaluation in high risk women. The present study examined to which extent guidelines are applied, and analyzed the effectiveness of GDM diagnosis according to risk profile.

METHODS AND RESULTS

We analyzed 1338 pregnant women, consecutively screened for GDM with a 75 g OGTT between January 2013 and December 2015, according to national guidelines. Diagnosis of GDM was based on IADPSG/WHO 2013 criteria. As many as 14.4% of screened women was at high risk, 64% at medium, 21.6% did not have any risk factor. Only 50% of high-risk women were appropriately screened at 16th-18th gestational weeks; 28% of them repeated the OGTT due to NGT. The overall prevalence of GDM was 39.9%, higher in high risk women (67% vs. 40% medium risk vs. 22% low risk; p < 0.0001). An early GDM diagnosis was performed in 40.7% of high-risk women. In low risk women, gestational weight gain at the screening time was independently associated with GDM.

CONCLUSIONS

The recommendations for the screening of GDM are still insufficiently implemented, especially for early evaluation in high risk women. Considering the high proportion of early GDM diagnosis, the poor adherence to screening recommendation may result in late diagnosis of GDM. Finally, our finding of a 22% prevalence of GDM among low risk women suggests the need to consider additional risk factors, such as excessive weight gain during pregnancy.

Early Pregnancy Biochemical Predictors of Gestational Diabetes Mellitus

PURPOSE OF REVIEW

Universal oral glucose tolerance-based screening is employed to identify pregnant women with gestational diabetes mellitus (GDM), as treatment of this condition decreases the risk of associated complications. A simple and accurate blood test which identifies women at low or high risk for GDM in the first trimester would have the potential to decrease costs and improve outcomes through prevention or treatment. This review summarizes published data on early pregnancy biomarkers which have been tested as predictors of GDM.

RECENT FINDINGS

A large number of first-trimester biochemical predictors of GDM have been reported, mostly in small case-control studies. These include glycemic markers (fasting glucose, post-load glucose, hemoglobin A1C), inflammatory markers (C-reactive protein, tumor necrosis factor-alpha), insulin resistance markers (fasting insulin, sex hormone-binding globulin), adipocyte-derived markers (adiponectin, leptin), placenta-derived markers (follistatin-like-3, placental growth factor, placental exosomes), and others (e.g., glycosylated fibronectin, soluble (pro)renin receptor, alanine aminotransferase, ferritin). A few large studies suggest that first-trimester fasting glucose or hemoglobin A1C may be useful for identifying women who would benefit from early GDM treatment. To translate the findings from observational studies of first-trimester biomarkers for GDM to clinical practice, trials or cost-effectiveness analyses of screening and treatment strategies based on these novel biomarkers are needed.

GESTATIONAL DIABETES MELLITUS - IS STILL A "MYSTERIOUS DISEASE" IN 2016?

Overview of necessity of universal screening as the tool for adequate diagnosis of GDM in 2016. Identifying of gestational diabetes mellitus (GDM) overpasses the medical discussion of utility, both for the mother and child, both for the short term and long term possible complications.

Single abnormal value on 3-hour oral glucose tolerance test during pregnancy is associated with adverse maternal and neonatal outcomes: a systematic review and metaanalysis

OBJECTIVE DATA

The purpose of this study was to determine whether women with 1 abnormal value on 3-hour 100-g oral glucose tolerance test are at an increased risk for adverse pregnancy outcomes.

STUDY

Gestational diabetes mellitus is diagnosed by a 2-step method, with a 3-hour, 100-g oral glucose tolerance test that is reserved for women with an abnormal 1-hour, 50-g glucose challenge test. Although the increased maternal-fetal morbidity with gestational diabetes mellitus is well established, controversy remains about the risk that is associated with an isolated abnormal value during a 3-hour, 100-g oral glucose tolerance test.

STUDY APPRAISAL AND SYNTHESIS METHODS

Prospective and retrospective studies that evaluated the maternal and perinatal impact of 1 abnormal glucose value during a 3-hour, 100-g oral glucose tolerance test were identified with the use of computerized databases. Data were extracted and quantitative analyses were performed.

RESULTS

Twenty-five studies (7 prospective and 18 retrospective) that met criteria for metaanalysis included 4466 women with 1 abnormal glucose value on oral glucose tolerance test. Patients with 1 abnormal glucose value had significantly worse pregnancy outcomes compared with women with zero abnormal values with the following pooled odds ratios: macrosomia, 1.59 (95% confidence interval, 1.16-2.19); large for gestational age, 1.38 (95% confidence interval, 1.09-1.76); increased mean birthweight, 44.5 g (95% confidence interval, 8.10-80.80 g); neonatal hypoglycemia, 1.88 (95% confidence interval, 1.05-3.38); total cesarean delivery, 1.69 (95% confidence interval, 1.40-2.05); pregnancy-induced hypertension, 1.55 (95% confidence interval, 1.31-1.83), and Apgar score of <7 at 5 minutes, 6.10 (95% confidence interval, 2.65-14.02). There was also an increase in neonatal intensive care unit admission and respiratory distress syndrome. Similar results were seen that compared 1 abnormal glucose value to a population with a normal 1-hour 50-g glucose challenge test (normal glucose screen). With the exception of birthweight, outcomes of patients with 1 abnormal glucose value were similar to outcomes of patients with gestational diabetes mellitus.

CONCLUSION

Women with 1 abnormal value on 3-hour, 100-g oral glucose tolerance test have a significantly increased risk for poor outcomes comparable with women who have gestational diabetes mellitus.

Impact of the new IADPSG gestational diabetes diagnostic criteria on pregnancy outcomes in Western Australia

BACKGROUND

There is debate as to the most appropriate diagnostic criteria to diagnose gestational diabetes mellitus (GDM). The proposed International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria have recently been endorsed by various bodies, but there remains no national consensus.

AIM

To assess the perinatal outcomes of women with GDM classified according to the 1998 Australasian Diabetes in Pregnancy Society (ADIPS) criteria compared to those with GDM by the IADPSG criteria.

MATERIALS AND METHODS

Results of glucose tolerance tests performed between January 2011 and January 2014 were linked with the perinatal data of those who delivered singleton fetuses after 24 weeks' gestation. Analysed data included birthweight, gestational age at birth, macrosomia, mode of delivery, perinatal mortality, nursery admission, maternal body mass index, and gestational weight gain.

RESULTS

Of 3571 women, 466 (13%) and 559 (16%) met the criteria for the 1998 ADIPS and IADPSG criteria for GDM, respectively. Those with GDM according to the IADPSG criteria only (6%) were more obese (95% CI 2.3-4.8 kg/m(2) ), delivered neonates on average 106 g heavier (95% CI 19-193 g) and had more fetal macrosomia (18% vs 11%, P = 0.002) than those with normal glucose tolerance.

CONCLUSIONS

The IADPSG criteria for GDM identified a group of women at previously unrecognised increased risk of adverse perinatal outcomes. Adopting the IADPSG criteria would increase the number of women diagnosed with GDM by 20%; however, the improvements in perinatal morbidity, in addition to potential long-term benefits, may justify the increase in healthcare workload.

Updated guidelines on screening for gestational diabetes

Gestational diabetes mellitus (GDM) is associated with an increased risk of complications for both mother and baby during pregnancy as well as in the postpartum period. Screening and identifying these high-risk women is important to improve short- and long-term maternal and fetal outcomes. However, there is a lack of international uniformity in the approach to the screening and diagnosis of GDM. The main purpose of this review is to provide an update on screening for GDM and overt diabetes during pregnancy, and discuss the controversies in this field. We take on debatable issues such as adoption of the new International association of diabetes and pregnancy study groups criteria instead of the Carpenter and Coustan criteria, one-step versus two-step screening, universal screening versus high-risk screening before 24 weeks of gestation for overt diabetes, and, finally, the role of HbA_1c as a screening test of GDM. This discussion is followed by a review of recommendations by professional bodies. Certain clinical situations, in which a pragmatic approach is needed, are highlighted to provide a comprehensive overview of the subject.