Role of HbA1c in post-partum screening of women with gestational diabetes mellitus

The utility of plasma glycated CD59 in predicting postpartum glucose intolerance: A prospective study of women diagnosed with GDM during a period of universal GDM screening

AIMS

Gestational diabetes (GDM) is associated with the development of postpartum (PP) glucose intolerance. Plasma glycated CD59 (pGCD59) is an emerging biomarker for the detection of hyperglycaemia. The aim of this study was to assess the ability of PP pGCD59 to predict the development of PP GI as defined by the 2 h 75 g OGTT using the ADA criteria, in a cohort of women diagnosed with prior GDM in the index pregnancy using the 2 h 75 g OGTT at 24-28 weeks of gestation according to the World Health Organization (WHO) 2013 criteria.

METHODS

Of the 2017 pregnant women recruited prospectively 140 women with gestational diabetes had samples for pGCD59 taken PP at the time of the OGTT. The ability of pGCD59 to predict the results of the PP OGTT was assessed using nonparametric receiver operating characteristic (ROC) curves.

RESULTS

Women with PP glucose intolerance had significantly higher PP pGCD59 levels compared to women with normal glucose tolerance PP (3.8 vs. 2.7 SPU). PP pGCD59 identified women who developed glucose intolerance PP with an AUC of 0.80 (95% CI: 0.70-0.91). A PP pGCD59 cut-off value of 1.9 SPU generated a sensitivity of 100% (95% CI: 83.9-100), specificity of 16.9% (95% CI: 9.8-26.3), positive predictive value of 22.1% (95% CI: 21.0-22.6), and negative predictive value of 100% (95% CI: 87.4-100). PP fasting plasma glucose generated an AUC of 0.96 (95% CI: 0.89-0.99) for the identification of PP glucose intolerance.

CONCLUSION

Our study found that PP pGCD9 may be a promising biomarker to identify women not requiring PP glucose intolerance screening using the traditional OGTT. While the diagnostic accuracy of pGCD59 is good, fasting plasma glucose remains a better test for the identification of PP glucose intolerance.

High prevalence and significant ethnic differences in actionable HbA1C after gestational diabetes mellitus in women living in Norway

BACKGROUND

The type 2 diabetes risk after gestational diabetes mellitus (GDM) is twice as high in South Asian compared to European women. Current guidelines differ regarding which test to use as a screening-tool post-GDM. We aimed to identify ethnic differences in the prevalence rates and early predictors for actionable HbA_1c (defined as prediabetes and diabetes) short time after GDM.

METHODS

This cross-sectional study, enrolling South Asian and Nordic women 1-3 years after a diagnosis of GDM, was undertaken at three hospitals in Norway. We performed a clinical and laboratory evaluation including an oral glucose tolerance test (OGTT). Medical records were used to retrieve data during pregnancy. Prediabetes was classified with HbA_1c alone or combined with OGTT glucose measurements according to the WHO, WHO-IEC, and ADA criteria (fasting plasma glucose (FPG) 6.1-6.9 mmol/L, FPG 6.1-6.9 mmol/L and/or HbA_1c 42-47 mmol/mol (6.0-6.4%), and FPG 5.6-6.9 mmol/L and/or HbA_1c 39-47 mmol/mol (5.7-6.4%)). Ethnic differences in prevalence and predictors of glucose deterioration were assed by χ² (Pearson) tests and logistic regression models.

RESULTS

We included 163 South Asian and 108 Nordic women. Actionable HbA_1c levels were highly prevalent and more so among South Asian than Nordic women (WHO-IEC-HbA_1c: 25.8% vs. 6.5% (p ≤ 0.001), ADA-HbA_1c: 58.3% vs. 22.2% (p ≤ 0.001)). Although adding OGTT-data gave higher combined prevalence rates of prediabetes and diabetes (WHO: 65.6% vs. 47.2% (p ≤ 0.05), WHO-IEC: 70.6% vs. 47.2% (p ≤ 0.001), ADA: 87.8% vs. 65.7% (p ≤ 0.001)), the excess risk in the South Asian women was best captured by the HbA_1c. Important predictors for glucose deterioration after GDM were: South Asian ethnicity, GDM before the index pregnancy, use of glucose-lowering drugs in pregnancy, higher age, and higher in-pregnancy fasting glucose levels.

CONCLUSIONS

In women with GDM 1-3 year previously, we found high prevalence and significant ethnic differences in actionable ADA-HbA_1c levels, with South Asian ethnicity, GDM before the index pregnancy, and the use of glucose-lowering drugs in pregnancy as the most important risk factors. This study reinforces the importance of annual screening-preferably with HbA_1c measurements-to facilitate early intervention after GDM.

Hyperglycemia First Detected in Pregnancy in South Africa: Facts, Gaps, and Opportunities

This review contextualizes hyperglycemia in pregnancy from a South-African perspective. It aims to create awareness of the importance of hyperglycemia in pregnancy in low-middle-income countries. We address unanswered questions to guide future research on sub-Saharan African women with hyperglycemia first detected in pregnancy (HFDP). South African women of childbearing age have the highest prevalence of obesity in sub-Saharan Africa. They are predisposed to Type 2 diabetes (T2DM), the leading cause of death in South African women. T2DM remains undiagnosed in many African countries, with two-thirds of people living with diabetes unaware. With the South African health policy's increased focus on improving antenatal care, women often gain access to screening for non-communicable diseases for the first time in pregnancy. While screening practices and diagnostic criteria for gestational diabetes mellitus (GDM) differ amongst geographical areas in South Africa (SA), hyperglycemia of varying degrees is often first detected in pregnancy. This is often erroneously ascribed to GDM, irrespective of the degree of hyperglycemia and not overt diabetes. T2DM and GDM convey a graded increased risk for the mother and fetus during and after pregnancy, with cardiometabolic risk accumulating across the lifespan. Resource limitations and high patient burden have hampered the opportunity to implement accessible preventative care in young women at increased risk of developing T2DM in the broader public health system in SA. All women with HFDP, including those with true GDM, should be followed and undergo glucose assessment postpartum. In SA, studies conducted early postpartum have noted persistent hyperglycemia in a third of women after GDM. Interpregnancy care is advantageous and may attain a favourable metabolic legacy in these young women, but the yield of return following delivery is suboptimal. We review the current best evidence regarding HFDP and contextualize the applicability in SA and other African or low-middle-income countries. The review identifies gaps and shares pragmatic solutions regarding clinical factors that may improve awareness, identification, diagnosis, and management of women with HFDP.

Women's engagement, views and experiences of postnatal follow-up after gestational diabetes mellitus in pregnancy

BACKGROUND

The evidence base relating to women's engagement and experiences of postnatal care following Gestational Diabetes Mellitus in the United Kingdom is limited. Additionally, the uptake of a postnatal fasting blood glucose testing following Gestational Diabetes Mellitus appears to be poor.

OBJECTIVE

This study aimed to explore women's engagement, views and experiences of postnatal care following Gestational Diabetes Mellitus in the United Kingdom.

DESIGN AND PARTICIPANTS

An online survey of participants that had Gestational Diabetes Mellitus was undertaken to gather mixed-methods data regarding women's engagement, views and experiences of postnatal care. Demographic data were also collected.

FINDINGS

A total of 31 participants completed the online survey; respondents were from two countries in the United Kingdom only (England and Wales). Some respondents indicated positive postnatal experiences following Gestational Diabetes Mellitus (such as good family support) with effective communication by some healthcare teams and screening coinciding with engagement with the routine six week follow-up appointment. Overall, findings indicated a general dissatisfaction with the care provided, mostly due to the inconsistency of information and advice in relation to the type of screening test and the timing, location and organisation of blood glucose screening and follow up care.

CONCLUSION

This study provides an insight into ways that may improve women's engagement, views and experiences of postnatal care following Gestational Diabetes Mellitus in England and Wales.

IMPLICATIONS FOR PRACTICE

Findings indicate a lack of consistent adherence to national guidance. A clear care pathway facilitating continuity of care for women in the postnatal period following Gestational Diabetes Mellitus, along with further education and support for health professionals, may improve the provision of postnatal care. The authors recognise the limitations of this small standalone study however, findings highlight the need for further exploration of postnatal follow up following Gestational Diabetes Mellitus in the UK.

The utility of diagnostic tests in the detection and prediction of glucose intolerance in the early and late postpartum period in women after gestational diabetes: a longitudinal cohort study

BACKGROUND

Due to diverging international recommendations, the unclear role of HbA1c and the lack of longitudinal data, we investigated the accuracy of diagnostic tests in the early and late postpartum in women with gestational diabetes (GDM) especially to predict future glucose-intolerance.

METHODS

This longitudinal cohort included 967 women with GDM from 2011 to 2020. A 75-g oGTT and HbA1c were performed at 4-12 weeks (early) postpartum. FPG and HbA1c were measured at 1 and 3-year (late) postpartum. ADA criteria were used as gold standards. At all time-points (4-12 weeks, 1-year and 3-year postpartum) women with diabetes and prediabetes were grouped together and referred to as glucose-intolerant, because at most 3% of the entire cohort population had diabetes at any time-point.

RESULTS

The prevalence of glucose-intolerance in the early postpartum was higher using FPG and HbA1c (27.5%) than oGTT criteria (18.2%). Only 48-80% of women diagnosed with glucose-intolerance in the early postpartum actually remained intolerant. This was especially low when FPG or oGTT were combined with HbA1c (1-year: ≤ 62% and 3-years: ≤ 50%). Regardless of the test used, 1/3 of women with initially normal glucose-tolerance became glucose-intolerant in the late postpartum. HbA1c was unrelated to iron status/intake, remained stable throughout, but poorly predicted future glucose-intolerance. In the longitudinal analyses, all diagnostic tests in the early postpartum showed acceptable specificities (74-96%) but poor sensitivities (all < 38%) to predict glucose-intolerance after only 10-months. At 1-year postpartum however, the combination of FPG and HbA1c could best predict glucose-intolerance 2-years later.

CONCLUSIONS

Combining FPG with HbA1c at 1-year postpartum represents a reliable choice to predict future glucose-intolerance. Given the poor prediction of tests including oGTT in the early postpartum, focus should rather be on continuous long-term screening.

Pregnancy outcomes among multi-ethnic women with different degrees of hyperglycaemia during pregnancy in an urban New Zealand population and their association with postnatal HbA1c uptake

BACKGROUND

Adverse pregnancy outcomes are more common in women with hyperglycaemia. Many women have suboptimal uptake of HbA1c testing postdelivery.

AIMS

To compare pregnancy outcomes among multi-ethnic women with different degrees of hyperglycaemia during pregnancy, and their association with postnatal HbA1c uptake after the introduction of email reminders.

MATERIALS AND METHODS

A retrospective and prospective single-centre study was conducted in South Auckland in 2639 women with early gestational diabetes mellitus (GDM) (diagnosed < 20 weeks), late GDM (diagnosed ≥ 20 weeks), overt diabetes in pregnancy, or known type 2 diabetes (T2DM) during pregnancy. Automated email reminders were sent to general practitioners to increase postnatal HbA1c screening.

RESULTS

HbA1c during pregnancy increased across the late GDM (n = 1425), early GDM (n = 148), overt diabetes (n = 573) and T2DM (n = 493) groups (P < 0.001). Stillbirth was least common in the late GDM group (0, 0.7, 0.5, and 1.9%, respectively, P < 0.001), as were caesarean delivery (32.7, 45.1, 39.4, and 53.5%, respectively, P < 0.001), large for gestational age (LGA) (14.7, 18.2, 22.3, and 30.5%, respectively, P < 0.001), small for gestational age (8.8, 16.7, 11.0, and 11.1%, respectively, P = 0.02), and preeclampsia/eclampsia (7.7, 9.2, 13.0, and 14.8%, respectively, P < 0.001). LGA and preeclampsia/eclampsia were more common among Pacific and Māori women than European women (LGA, 30.1, 22.7, 10.3%, respectively, P < 0.001; preeclampsia/eclampsia, 13.5, 14.0, and 8.1%, respectively, P < 0.001). Postpartum HbA1c screening increased among women with GDM/overt diabetes after the introduction of the reminder emails (39.6% vs 34.0%, P = 0.03).

CONCLUSIONS

Women with late GDM are least likely to experience adverse outcomes. Email reminders to improve postpartum HbA1c screening warrant further investigation.

Facilitators and Barriers to Post-partum Diabetes Screening Among Mothers With a History of Gestational Diabetes Mellitus-A Qualitative Study From Singapore

Introduction: Gestational Diabetes Mellitus (GDM) affects one in six births worldwide. Mothers with GDM have an increased risk of developing post-partum Type-2 Diabetes Mellitus (T2DM). However, their uptake of post-partum diabetes screening is suboptimal, including those in Singapore. Literature reports that the patient-doctor relationship, mothers' concerns about diabetes, and family-related practicalities are key factors influencing the uptake of such screening. However, we postulate additional factors related to local society, healthcare system, and policies in influencing post-partum diabetes screening among mothers with GDM. Aim: The qualitative research study aimed to explore the facilitators and barriers to post-partum diabetes screening among mothers with GDM in an Asian community. Methods: In-depth interviews were carried out on mothers with GDM at a public primary care clinic in Singapore. Mothers were recruited from those who brought their child for vaccination appointments and their informed consent was obtained. Both mothers who completed post-partum diabetes screening within 12 weeks after childbirth and those who did not were purposively recruited. The social ecological model (SEM) provides the theoretical framework to identify facilitators and barriers at the individual, interpersonal, organizational, and policy levels. Results: Twenty multi-ethnic Asian mothers with GDM were interviewed. At the individual and interpersonal level, self-perceived risk of developing T2DM, understanding the need for screening and the benefits of early diagnosis, availability of confinement nanny in Chinese family, alternate caregivers, emotional, and peer support facilitated post-partum diabetes screening. Barriers included fear of the diagnosis and its consequences, preference for personal attention and care to child, failure to find trusted caregiver, competing priorities, and unpleasant experiences with the oral glucose tolerance test. At the organizational and public policy level, bundling of scheduled appointments, and standardization of procedure eased screening but uptake was hindered by inconvenient testing locations, variable post-partum care practices and advice in the recommendations for diabetes screening. Conclusion: Based on the SEM, facilitators and barriers towards post-partum diabetes screening exist at multiple levels, with some contextualized to local factors. Interventions to improve its uptake should be multi-pronged, targeting not only at personal but also familial, health system, and policy factors to ensure higher level of success.

Expression and influence of pentraxin-3, HbAlc and ApoA1/ApoB in serum of patients with acute myocardial infarction combined with diabetes mellitus type 2

The present study investigated the clinical significance of changes in levels of hypersensitive plasma pentraxin-3 (PTX3), hemoglobin A1c (HbAlc) and apolipoprotein A-I (ApoA1)/apolipoprotein B (ApoB) on patients with acute myocardial infarction (AMI) and diabetes mellitus type 2 (T2DM). After admission, 100 patients diagnosed with AMI combined with T2DM were selected as Group A. According to the level of fasting blood glucose (FBG), they were then subdivided into Group A1 (n=44) with FBG ≥13.0 mmol/l and Group A2 (n=56) with FBG <13.0 mmol/l. A total of 100 hospitalized patients with AMI in People's Hospital of Dongying (Dongying, China) were collected as Group B, and 100 healthy people receiving physical examination in the Physical Examination Center of People's Hospital of Dongying were selected as Group C. Serum PTX3, HbAlc and ApoA1/ApoB of all the study participants were tested, and diseased coronary artery vessels were divided into single-, double- and triple-vessel lesions according to their numbers. Logistic regression analysis was performed for the number of diseased coronary artery vessels and each index. The level of PTX3 in Group A1 was higher than that in Group A2; the level of ApoA1/ApoB in the former was lower than that in the latter (P<0.05); and the level of HbAlc in the former was significantly higher than that in the latter (P<0.01); the levels of PTX3 and HbA1c in Group A2 were higher than those in Group B, while the level of ApoA1/ApoB in the former was lower than that in the latter (P<0.05). Logistic regression analysis showed that the number of diseased coronary artery vessels was positively correlated with PTX3 and HbA1c, but negatively correlated with ApoA1/ApoB. PTX3, HbAlc and ApoA1/apoB have a certain clinical significance in assessing the severity of AMI combined with T2DM.

Paths to improving care of Australian Aboriginal and Torres Strait Islander women following gestational diabetes

Aim

To understand enablers and barriers influencing postpartum screening for type 2 diabetes following gestational diabetes in Australian Indigenous women and how screening might be improved.

Background

Australian Indigenous women with gestational diabetes mellitus (GDM) are less likely than other Australian women to receive postpartum diabetes screening. This is despite a fourfold higher risk of developing type 2 diabetes within eight years postpartum.

Methods

We conducted interviews with seven Indigenous women with previous GDM, focus groups with 20 Indigenous health workers and workshops with 24 other health professionals. Data collection included brainstorming, visualisation, sorting and prioritising activities. Data were analysed thematically using the Theoretical Domains Framework. Barriers are presented under the headings of ‘capability’, ‘motivation’ and ‘opportunity’. Enabling strategies are presented under ‘intervention’ and ‘policy’ headings.

Findings

Participants generated 28 enabling environmental, educational and incentive interventions, and service provision, communication, guideline, persuasive and fiscal policies to address barriers to screening and improve postpartum support for women. The highest priorities included providing holistic social support, culturally appropriate resources, improving Indigenous workforce involvement and establishing structured follow-up systems. Understanding Indigenous women’s perspectives, developing strategies with health workers and action planning with other health professionals can generate context-relevant feasible strategies to improve postpartum care after GDM. Importantly, we need evidence which can demonstrate whether the strategies are effective.

HbA1c as a predictor of diabetes after gestational diabetes mellitus

AIM

We wanted to investigate third-trimester HbA1c as a predictor of diabetes after gestational diabetes mellitus (GDM).

METHODS

Women with GDM were followed up prospectively for five years from pregnancy to detect the development of diabetes. The ability of HbA1c to predict diabetes was evaluated with receiver-operating characteristic (ROC) curves and logistic regression analysis.

RESULTS

By five years, 73 of 196 women had been diagnosed with diabetes. An optimal cut-off point for HbA1c of 36mmol/mol (5.4%) could predict diabetes with 45% sensitivity and 92% specificity. For HbA1c ≥39mmol/mol (≥5.7%), sensitivity, specificity, and positive predictive value were 30%, 97%, and 91%, respectively. In logistic regression analysis, adjusting for the diagnostic glucose concentration during pregnancy, HbA1c levels in the upper quartile (≥36mmol/mol) were associated with a 5.5-fold increased risk of diabetes.

CONCLUSION

Third-trimester HbA1c levels in the pre-diabetes range revealed women with post-partum diabetes with high specificity and high positive predictive value. HbA1c testing could be used as a strategy to select high-risk women for lifestyle interventions aimed at prevention of diabetes starting during pregnancy. The results should encourage further validation in other populations using new diagnostic criteria for GDM.

Is There a Role for HbA1c in Pregnancy?

Outside pregnancy, HbA1c analysis is used for monitoring, screening for and diagnosing diabetes and prediabetes. During pregnancy, the role for HbA1c analysis is not yet established. Physiological changes lower HbA1c levels, and pregnancy-specific reference ranges may need to be recognised. Other factors that influence HbA1c are also important to consider, particularly since emerging data suggest that, in early pregnancy, HbA1c elevations close to the reference range may both identify women with underlying hyperglycaemia and be associated with adverse pregnancy outcomes. In later pregnancy, HbA1c analysis is less useful than an oral glucose tolerance test (OGTT) at detecting gestational diabetes. Postpartum, HbA1c analysis detects fewer women with abnormal glucose tolerance than an OGTT, but the ease of testing may improve follow-up rates and combining HbA1c analysis with fasting plasma glucose or waist circumference may improve detection rates. This article discusses the relevance of HbA1c testing at different stages of pregnancy.