Evolution of diagnostic criteria for gestational diabetes mellitus

Prevalence of gestational diabetes in the United States and Canada: a systematic review and meta-analysis

BACKGROUND

An understanding of the prevalence of gestational diabetes mellitus among pregnant women is essential at local, national and international level so that appropriate health care interventions can be planned, financed and delivered.

METHODS

A systematic review and meta-analysis of primary research reporting the prevalence of gestational diabetes mellitus in Canada or the United States were carried out according to Meta-analysis of Observational Studies in Epidemiology guidelines. Four electronic databases were systematically searched in June 2023 to identify articles that reported gestational diabetes mellitus prevalence using universal screening in pregnant women from eligible general population samples. Estimates were combined using a random effects model, and the effects of moderator variables analysed.

RESULTS

There were 36 separate samples of women or deliveries (total sample size 1,550,917). Overall mean prevalence of gestational diabetes mellitus was 6.9% (95% CI: 5.7-8.3); 13.7% (95% CI: 10.7-17.3) in studies using a one-step screening strategy, and 5.2% (95% CI: 4.4-6.1) in those using a two-step strategy. Heterogeneity in technical methods between studies produced differences in estimates, as did different diagnostic thresholds used.

CONCLUSIONS

The meta-analysis suggests a slightly higher prevalence of gestational diabetes mellitus in Canada and the United States, compared to Europe, but highlights the need for standardised protocols for estimating gestational diabetes mellitus prevalence.

Large-Scale Data Harmonization Across Prospective Studies

The Preconception Period Analysis of Risks and Exposures Influencing Health and Development (PrePARED) Consortium creates a novel resource for addressing preconception health by merging data from numerous cohort studies. In this paper, we describe our data harmonization methods and results. Individual-level data from 12 prospective studies were pooled. The crosswalk-cataloging-harmonization procedure was used. The index pregnancy was defined as the first postbaseline pregnancy lasting more than 20 weeks. We assessed heterogeneity across studies by comparing preconception characteristics in different types of studies. The pooled data set included 114,762 women, and 25,531 (22%) reported at least 1 pregnancy of more than 20 weeks' gestation during the study period. Babies from the index pregnancies were delivered between 1976 and 2021 (median, 2008), at a mean maternal age of 29.7 (standard deviation, 4.6) years. Before the index pregnancy, 60% of women were nulligravid, 58% had a college degree or more, and 37% were overweight or obese. Other harmonized variables included race/ethnicity, household income, substance use, chronic conditions, and perinatal outcomes. Participants from pregnancy-planning studies had more education and were healthier. The prevalence of preexisting medical conditions did not vary substantially based on whether studies relied on self-reported data. Use of harmonized data presents opportunities to study uncommon preconception risk factors and pregnancy-related events. This harmonization effort laid the groundwork for future analyses and additional data harmonization.

Cholesterol biosynthesis modulates differentiation in murine cranial neural crest cells

Cranial neural crest cells (cNCC) are a multipotent embryonic cell population that give rise to a diverse set of cell types. These cells are particularly vulnerable to external metabolic stressors, as exemplified by the association between maternal hyperglycemia and congenital malformations. We were interested in studying the effect of various concentrations of glucose and pyruvate on cNCC metabolism, migration, and differentiation using an established murine neural crest cell model (O9-1). We unexpectedly observed a pattern of gene expression suggestive of cholesterol biosynthesis induction under glucose depletion conditions in O9-1 cells. We further showed that treatment with two different cholesterol synthesis inhibitors interfered with cell migration and differentiation, inhibiting chondrogenesis while enhancing smooth muscle cell differentiation. As congenital arhinia (absent external nose), a malformation caused by mutations in SMCHD1, appears to represent, in part, a defect in cNCC, we were also interested in investigating the effects of glucose and cholesterol availability on Smchd1 expression in O9-1 cells. Smchd1 expression was induced under high glucose conditions whereas cholesterol synthesis inhibitors decreased Smchd1 expression during chondrogenesis. These data highlight a novel role for cholesterol biosynthesis in cNCC physiology and demonstrate that human phenotypic variability in SMCHD1 mutation carriers may be related, in part, to SMCHD1's sensitivity to glucose or cholesterol dosage during development.

Maternal dietary pattern in early pregnancy is associated with gestational weight gain and hyperglycemia: A cohort study in South West of Iran

BACKGROUND AND AIMS

Maternal dietary pattern could influence on fetal health outcome. Thus, this study was conducted to evaluate the relationship between maternal dietary pattern and Gestational Weight Gain (GWG) in each trimester and hyperglycemia amongst Arab pregnant women in south-west of Iran.

METHODS

This longitudinally study was performed in urban healthcare centers of south-west of Iran. Among 610 candidates, 488 pregnant women were included in the final analysis. Consequently, two diet patterns were determined by principal component analysis and the association between GWG and blood glucose level was determined using quartile regression. Using generalized linear model, a model was adjusted for pre-pregnancy BMI, maternal age, income, and education levels.

RESULTS

Two dietary patterns were identified as follows: "high fat -fast food" and "vegetable-fruits & protein" pattern. High adherence to "high fat -fast food" pattern was associated with higher GWG and hyperglycemia in 3rd trimester (adjusted β: 0.029 95%CI 0.012; 0.049 P = 0.001) (adjusted β: 0.029 95%CI 0.012; 0.049 P = 0.001) respectively. High tendency to "vegetable-fruits & protein" pattern was inversely associated with development of hyperglycemia in 3rd trimester. Higher SES level was associated with low adherence to "high fat-fast food" pattern.

CONCLUSION

Findings of the study revealed that, higher adherence to high -fat diet is related to excessive GWG and hyperglycemia in late pregnancy.

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.

Influence of different diagnostic criteria on gestational diabetes mellitus incidence and medical expenditures in China

AIMS/INTRODUCTION

To summarize the development of the criteria for diagnosing gestational diabetes mellitus (GDM) in China, and investigate how different GDM diagnostic criteria influence the national prevalence of GDM, the national health system and the economic burden of GDM in China.

MATERIALS AND METHODS

Retrospectively using data from women undergoing a 2-h, 75-g oral glucose tolerance test at 24-28 gestational weeks in the First Affiliated Hospital of Jinan University (Guangzhou, Guangdong, China) from January 2011 to December 2017, the prevalence rate of GDM and its impacts on the national health system were evaluated using different criteria (the 7th edition textbook criteria, National Diabetes Data Group 1979, World Health Organization 1985, European Association for the Study of Diabetes 1996, Japan 2002, American Diabetes Association [ADA] 2011 [International Association of the Diabetes and Pregnancy Study Groups], and National Institute for Heath and Care Excellence 2015).

RESULTS

The incidence rates of GDM based on the ADA 2011 and National Institute for Heath and Care Excellence 2015 were, respectively, 22.94% (P < 0.01) and 21.72% (P < 0.01), over threefold higher than implementing the 7th edition textbook criteria (P < 0.001). On the contrary, the incidence rates of GDM diagnosed with the National Diabetes Data Group 1979 and World Health Organization 1985 guidelines were significantly less than the 7th edition textbook criteria (P < 0.001). From 2001 to 2016, the estimated national cost of treating GDM rose from ¥3.9 billion to ¥27.4 billion after implementing the ADA 2011 guidelines.

CONCLUSIONS

With the implementation of ADA 2011 (International Association of the Diabetes and Pregnancy Study Groups) guidelines, there are fewer adverse perinatal outcomes and cases of type 2 diabetes mellitus in the long term, but the medical costs increased significantly, and the cost-effectiveness of diagnostic criteria in China is still yet to be confirmed.

Prevalence of gestational diabetes mellitus and results of the screening tests at a tertiary referral center: A cross-sectional study

OBJECTIVE

This study aimed to identify the gestational diabetes mellitus (GDM) prevalence of low risk pregnant population at a tertiary referral center by different approaches.

MATERIAL AND METHODS

A cross-sectional study using retrospective data between 2007-2017 was conducted. During this period 77227 patients underwent either two step or one step glucose tolerance tests.

RESULTS

The median age of the study population was 27 (15-49). Fasting plasma glucose (FPG) testing was evaluated in 144,113 women at the initial antenatal care visit which %21 of these were between 92-126 mg/dL. Of these women %1.25 had FPG>126 mg/dL which showed the prevalence of pregestational diabetes in our cohort. During the study period 74412 women underwent 50-g glucose challenge test where %18 were screen positive and % 2.9 was defined as gestational diabetic without need for further testing (>180 mg/dL). The screening positive patients were sent to 100-g oral glucose tolerance test and the prevalence of GDM with two-step screening was 5.5%. A total of 2815 patients were screened by 75-g glucose tolerance test and the prevalence of GDM with one-step screening was 21%. Overall 4684 patients have been diagnosed as gestational diabetes mellitus with the prevalence of 6.07%.

CONCLUSION

Fasting plasma glucose >92 mg/dL is challenging in our population due to improper fasting. The FPG dependent GDM prevalence is almost four times higher than two-step glucose screening test results (21.8% vs 5.5%). If FPG levels will be used for diagnosing GDM then the values must be checked in a second laboratory analysis.

Hepatitis B surface antigen positivity during pregnancy and risk of gestational diabetes mellitus: A systematic review and meta-analysis

Chronic hepatitis B virus (HBV) infection is a prevalent public health issue worldwide. Its impact on important pregnancy outcomes, such as gestational diabetes mellitus (GDM), has not been clearly established. The findings from published studies are inconsistent. In this systematic review and meta-analysis, we aimed to clarify whether HBV infection manifested during pregnancy is associated with an increased risk of GDM. We searched MEDLINE and EMBASE for cohort studies and case-control studies that investigated the association between maternal hepatitis B surface antigen (HBsAg) positivity and GDM. We pooled adjusted odds ratio (aOR) and unadjusted OR, respectively, using the random-effect generic inverse variance method. We assessed risk of bias using the Quality in Prognosis Studies tool and conducted five pre-specified subgroup analyses. In total, 23 cohort studies involving 3 529 223 participants were included. The risk of GDM was 6.48% (1868/28 829) among HBsAg-positive pregnant women and 3.41% (119 283/3 500 394) among HBsAg-negative pregnant women. Meta-analyses of both unadjusted and adjusted effect estimates showed that HBsAg positivity during pregnancy was associated with higher risk of developing GDM (unadjusted OR 1.35, 95% CI: 1.17 to 1.56, I²  = 82.6%; adjusted OR 1.47, 1.22 to 1.76, I²  = 62%). Among pre-specified subgroup analysis, significant differences were found among studies with high vs low or moderate risk of bias. The results were robust to sensitivity analyses. In conclusion, HBsAg positivity during pregnancy has a moderate effect on an increased risk of GDM. Given the size of the population with HBV infection worldwide, however, this effect could have substantial impact on pregnancy. Further studies are warranted to investigate whether active infection with HBeAg positivity would further elevate the risk of adverse events during pregnancy.

Gestational Diabetes Testing, Narrative, and Medical Distrust

In this article, we investigate the role of scientific and patient narratives on perceptions of the medical debate around gestational diabetes (GDM) testing. Among medical scientists, we show that the narrative surrounding GDM testing affirms that future research and data will lead to medical consensus. We call this narrative trajectory the "deferred quest." For patients, however, diagnosis and their subsequent discovery that biomedicine does not speak in one voice ruptures their trust in medical authority. This new distrust creates space for patients to develop a Frankian quest narrative where they become the protagonist in their story. Additionally, across these different narratives, we observe how character is constructed and employed to negotiate trust. We conclude that healthcare providers should assess the narrative trajectory adopted by patients after diagnosis. Also, we suggest that providers acknowledge the lack of medical consensus to their patients. This veracity would foster women's sense of trust in their provider as well as allow women to be active interlocutors in a debate that ultimately plays out in their deliberation about their body, pregnancy, and risk.

Hemoglobin A1c as screening for gestational diabetes mellitus in Nordic Caucasian women

BACKGROUND

Gestational diabetes mellitus (GDM) increases the risk for preeclampsia and macrosomia. GDM is conventionally diagnosed by an oral glucose tolerance test (OGTT). Hemoglobin A1c (HbA1c) is a marker for the average glucose level the last 2-3 months. We aimed to study if HbA1c alone or in combination with patient characteristics can be used to screen for GDM and reduce the number of OGTTs, and whether it could predict preeclampsia or birth weight.

METHODS

855 women from a previous study on the effect of exercise on GDM prevalence were eligible, whereof 677 were included. GDM was diagnosed by WHO 1999 criteria (GDM-WHO) and modified IADPSG criteria (GDM-IADPSG), at pregnancy weeks 18-22 and 32-36. HbA1c analyzed at pregnancy weeks 18-22 and 32-36, variables from patient history and clinical examination were considered for logistic regression models. The diagnostic accuracy was assessed by ROC curve analysis.

RESULTS

Accumulated GDM prevalence was 6.7 % by WHO and 7.2 % by modified IADPSG criteria. Nearly a third could potentially have avoided an OGTT by using HbA1c to exclude GDM-IADPSG with a sensitivity of 88 % at week 18-22 and 97 % at week 32-36. Further, 16 % could have avoided an OGTT with a sensitivity of 96 % using HbA1c at week 18-22 to exclude GDM-IADPSG throughout pregnancy. HbA1c was not accurate at diagnosing GDM-IADPSG, and it was inaccurate at screening for GDM-WHO at any time point. Adding other predictors did not increase the number of potentially avoidable OGTTs significantly. HbA1c was not significantly associated with preeclampsia or birth weight.

CONCLUSIONS

HbA1c could potentially reduce the number of OGTTs.

The relative importance of maternal body mass index and glucose levels for prediction of large-for-gestational-age births

Background

The risk of gestational diabetes mellitus (GDM) increases substantially with increasing maternal body mass index (BMI). The aim of the present study was to evaluate the relative importance of maternal BMI and glucose levels in prediction of large-for-gestational-age (LGA) births.

Method

This observational cohort study was based on women giving birth in southern Sweden during the years 2003–2005. Information on 10 974 pregnancies was retrieved from a population-based perinatal register. A 75-g oral glucose tolerance test (OGTT) was performed in the 28 week of pregnancy for determination of the 2-h plasma glucose concentration. BMI was obtained during the first trimester. The dataset was divided into a development set and a validation set. Using the development set, multiple logistic regression analysis was used to identify maternal characteristics associated with LGA. The prediction of LGA was assessed by receiver-operating characteristic (ROC) curves, with LGA defined as birth weight > +2 standard deviations of the mean.

Results

In the final multivariable model including BMI, 2-h glucose level and maternal demographics, the factor most strongly associated with LGA was BMI (odds ratio 1.1, 95 % confidence interval [CI] 1.08–1.30). Based on the total dataset, the area under the ROC curve (AUC) of 2-h glucose level to predict LGA was 0.54 (95 % CI 0.48–0.60), indicating poor performance. Using the validation database, the AUC for the final multiple model was 0.69 (95 % CI 0.66–0.72), which was identical to the AUC retrieved from a model not including 2-h glucose (0.69, 95 % CI 0.66–0.72), and larger than from a model including 2-h glucose but not BMI (0.63, 95 % CI 0.60–0.67).

Conclusions

Both the 2-h glucose level of the OGTT and maternal BMI had a significant effect on the risk of LGA births, but the relative contribution was higher for BMI. The findings highlight the importance of concentrating on healthy body weight in pregnant women and closer monitoring of weight during pregnancy as a strategy for reducing the risk of excessive fetal growth.

HbA1c as screening for gestational diabetes mellitus in women with polycystic ovary syndrome

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with adverse pregnancy outcomes such as preeclampsia and macrosomia. Women with polycystic ovary syndrome (PCOS) are at increased risk of developing GDM. Today, GDM is diagnosed by oral glucose tolerance test (OGTT), a rather cumbersome test for the women and health care system. The objectives of this study were to investigate whether HbA1c in first trimester of pregnancy could be used as a screening test for GDM in first trimester and throughout pregnancy in order to reduce the number of OGTTs, and whether it could predict preeclampsia and macrosomia in women with PCOS.

METHODS

Post hoc analyses of data from 228 women from a prospective, randomised, multicenter study comparing metformin to placebo from first trimester to delivery. Fasting and 2-h plasma glucose were measured during a 75 g OGTT in first trimester, gestational week 19 and 32 as well as fasting plasma glucose in gestational week 36. GDM was diagnosed by WHO criteria from 1999 in first trimester and throughout pregnancy and by modified IADPSG criteria (i.e. lacking the 1-h plasma glucose value) in first trimester. The diagnostic accuracy was assessed by logistic regression and ROC curve analysis.

RESULTS

The area under the ROC curve for first trimester HbA1c for screening of GDM diagnosed by WHO criteria in first trimester was 0.60 (95 % CI 0.44-0.75) and 0.56 (95 % CI 0.47-0.65) for GDM diagnosed throughout pregnancy. Only 2.2 % (95 % CI 0.7-5.1 %) of the participants could have avoided OGTT. HbA1c was not statistically significantly associated with GDM diagnosed by modified IADPSG criteria in first trimester. However, first trimester HbA1c was statistically significantly associated with preeclampsia. Both HbA1c and GDM by WHO criteria in first trimester, but not by IADPSG, were negatively associated with birth weight.

CONCLUSION

First trimester HbA1c can not be used to exclude or predict GDM in women with PCOS, but it might be better to predict preeclampsia than the GDM diagnosis.

A proposal for the use of uniform diagnostic criteria for gestational diabetes in Europe: an opinion paper by the European Board & College of Obstetrics and Gynaecology (EBCOG)

Screening and diagnostic criteria for gestational diabetes (GDM) are inconsistent across Europe, and the development of a uniform GDM screening strategy is necessary. Such a strategy would create opportunities for more women to receive timely treatment for GDM. Developing a consensus on screening for GDM in Europe is challenging, as populations are diverse and healthcare delivery systems also differ. The European Board & College of Obstetrics and Gynaecology (EBCOG) has responded to this challenge by appointing a steering committee, including members of the EBCOG and the Diabetic Pregnancy Study Group (DPSG) associated with the EASD, to develop a proposal for the use of uniform diagnostic criteria for GDM in Europe. A proposal has been developed and has now been approved by the Council of the EBCOG. The current proposal is to screen for overt diabetes at the first prenatal contact using cut-off values for diabetes outside pregnancy, with particular efforts made to screen high-risk groups. When screening for GDM is performed at 24 weeks' gestation or later, the proposal is now to use the 75 g OGTT with the new WHO diagnostic criteria for GDM. However, more research is necessary to evaluate the best GDM screening strategy for different populations in Europe. Therefore, no clear recommendation has been made on whether a universal one-step, two-step or a risk-factor-based screening approach should be used. The use of the same WHO diagnostic GDM criteria across Europe will be an important step towards uniformity.

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.

Association between fetal abdominal circumference and birthweight in maternal hyperglycemia

OBJECTIVES

To compare fetal abdominal circumference and its relationship with birthweight at increasing gestational ages in the context of maternal hyperglycemia of varying severity.

DESIGN

Retrospective cohort study.

SETTING

Two centers participated in building one database.

POPULATION

A total of 1538 Korean pregnant women were subjected to a two-step approach to diagnose gestational diabetes mellitus.

METHODS

Pregnant women were classified into gestational diabetes mellitus, borderline gestational diabetes mellitus, and normal groups. Fetal abdominal circumferences, which were measured with ultrasound at 4-week intervals starting at 16 weeks of gestation and ending prior to delivery, were evaluated in the groups.

MAIN OUTCOME MEASURE

The significance of fetal abdominal circumferences as predictors or risk factors of macrosomia/large-for-gestational age.

RESULTS

Fetal abdominal circumferences measured from 16 weeks of gestation until prior to delivery predicted birthweight in all groups with some exceptions. Fetal abdominal circumferences measured from 32 weeks of gestation until prior to delivery were predictive of macrosomia in all groups. Fetal abdominal circumferences measured from 28 weeks of gestation until prior to delivery were predictive of neonates being large-for-gestational age in all groups. Fetal abdominal circumferences measured at 16 and 24 weeks of gestation were also predictive of large-for-gestational age in the borderline gestational diabetes mellitus group. Fetal abdominal circumference measured at 24 weeks of gestation was also a predictor of macrosomia/large-for-gestational age in normal women.

CONCLUSIONS

Fetal abdominal circumferences measured during the second and especially third trimesters were significantly associated with excessive birthweight, irrespective of the severity of maternal glucose intolerance.

Ultrasound-guided compared to conventional treatment in gestational diabetes leads to improved birthweight but more insulin treatment: systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis of randomized controlled trials assessing ultrasound-guided versus conventional management in women with a broad severity-spectrum of gestational diabetes mellitus.

DESIGN

Systematic review and meta-analysis of trials published until August 2012.

SETTING

PubMed and Web of Science databases.

STUDY SELECTION AND METHODS

Eighteen studies were reviewed in full text. Eligibility criteria were (i) randomized controlled trials comparing metabolic management in women with gestational diabetes mellitus and ultrasound-based vs. the conventional management to assess fetal growth, (ii) representative of the whole spectrum of hyperglycemia and fetal growth, (iii) data on perinatal outcomes. Review Manager 5.0 was used to summarize the results.

RESULTS

Two studies fulfilled inclusion criteria. The ultrasound-guided group had a lower rate of large-for-gestational age newborns (relative risk 0.58, 95% confidence interval 0.34-0.99), macrosomia (relative risk 0.32, 95% confidence interval 0.11-0.95) and abnormal birthweight (small/large-for-gestational age, relative risk 0.64, 95% confidence interval 0.45-0.93) and a higher rate of insulin treatment (relative risk 1.58, 95% confidence interval 1.14-2.20). The number of women with gestational diabetes with a need to treat to prevent an additional newborn with abnormal birthweight was 10.

CONCLUSIONS

In women with a broad severity-spectrum of gestational diabetes mellitus, ultrasound-guided management improves birthweight distribution, but increases the need for insulin treatment. More research is needed in this area because results are derived from a limited number of patients.