Evidence for the utility of antenatal HbA1c to predict early postpartum diabetes after gestational diabetes in South Africa

Risk factors associated with early postpartum glucose intolerance in women with a history of gestational diabetes mellitus: a systematic review and meta-analysis

PURPOSE

This meta-analysis was aimed at exploring the incidence and risk factors of glucose intolerance in women with gestational diabetes mellitus (GDM) at 6-12 weeks postpartum to inform the development of preventive strategies.

METHOD

We searched Pubmed, Embase, Web of Science, the Cochrane Library, Ovid, China Knowledge Resource Integrated Database (CNKI), Wanfang Database and China Biology Medicine Database for entries between January 1990 and September 2022. The search terms included gestational diabetes mellitus, postpartum, glucose intolerance and type 2 diabetes. The meta-analysis was conducted using Stata 14.0.

RESULT

We included 37 studies, with 21 and 16 having low and medium risk of bias, respectively. The incidence of glucose intolerance in women with GDM 6-12 weeks postpartum was 27% (95% CI: 0.22-0.33). The following risk factors for GDM 6-12 weeks postpartum were identified: insulin use during pregnancy (OR = 3.23; 95% CI: 2.35-4.44), family history of diabetes (OR = 2.94; 95% CI: 1.98-4.33), abnormal fasting glucose levels at 24-28 weeks of gestation (OR = 1.15; 95% CI: 1.07-1.25), high pre-pregnancy BMI (OR = 1.63; 95% CI: 1.23-2.15), abnormal triglyceride levels during 28-40 weeks of gestation (OR = 2.18; 95% CI: 1.18-4.03), abnormal HbA1c levels at 28-40 weeks of gestation (OR = 6.62; 95% CI: 4.71-9.30), history of previous GDM (OR = 2.11; 95% CI: 1.27-3.49), and high 1-h glucose levels at 24-28 weeks of gestation (OR = 1.16; 95% CI:1.06-1.28).

CONCLUSION

The incidence of glucose intolerance in GDM patients at 6-12 weeks postpartum was high. To prevent early postpartum glucose intolerance, healthcare providers should develop individualized interventions for GDM patients, depending on existing risk factors.

The association between maternal HbA1c and adverse outcomes in gestational diabetes

BACKGROUND

The role of HbA1c in women with gestational diabetes mellitus (GDM) is still unclear, particularly in the Asian population.

AIM

To investigate the association between HbA1c levels and adverse outcomes considering maternal age, pre-pregnancy body mass index (BMI), and gestational weight gain (GWG) in women with GDM.

METHOD

A retrospective study included 2048 women with GDM and singleton live births. Using logistic regression, the associations between HbA1c and adverse pregnancy outcomes were assessed.

RESULT

Compared to women with HbA1c ≤ 5.0%, HbA1c was significantly associated with macrosomia (aOR 2.63,95%CI1.61,4.31), pregnancy-induced hypertension (PIH, aOR 2.56,95%CI1.57,4.19), preterm birth (aOR 1.64,95%CI 1.05,2.55), and primary Cesarean section (primary C-section, aOR1.49,95%CI1.09,2.03) in GDM women with HbA1c ≥5.5% while significantly associated with PIH (aOR 1.91,95%CI1.24,2.94) in women with HbA1c 5.1-5.4%. The associations between HbA1c and adverse outcomes varied with maternal age, pre-pregnancy BMI, and GWG. In women aged ≤29 years, there's significant association between HbA1c and primary C-section when HbA1c was 5.1-5.4% and ≥5.5%. In women aged 29-34 years and HbA1c ≥5.5%, HbA1c was significantly associated with macrosomia. In women aged ≥35 years, there's significant association between HbA1c and preterm birth when HbA1c was 5.1-5.4% and macrosomia and PIH when HbA1c ≥5.5%. In pre-pregnant normal-weight women, HbA1c was significantly associated with macrosomia, preterm birth, primary C-section, and PIH when HbA1c ≥5.5% while HbA1c was significantly associated with PIH when HbA1c was 5.1-5.4% . In pre-pregnant underweight women with HbA1c 5.1-5.4%, HbA1c was significantly associated with primary C-section. HbA1c was significantly associated with macrosomia among women with inadequate GWG or excess GWG and HbA1c≥5.5%. In women with adequate GWG, there's significant association between HbA1c and PIH when HbA1c was 5.1-5.4% and ≥5.5% .

CONCLUSION

Conclusively, HbA1c at the time of diagnosis is significantly associated with macrosomia, preterm birth, PIH, and primary C-section in Chinese women with GDM.

Early pregnancy glycaemia predicts postpartum diabetes mellitus

OBJECTIVE

To determine the association between early pregnancy glycaemia, as measured by glycosylated haemoglobin A1c (HbA1c) at the first prenatal visit, and persistent postpartum diabetes mellitus (DM).

STUDY DESIGN

All women first diagnosed with DM during pregnancy who had both HbA1c prior to 24 weeks and postpartum DM testing were included. The proportions of women with normal (<5.7%), prediabetic (5.7-6.4%) and elevated (≥6.5%) early HbA1c who tested positive for postpartum DM were compared. Test characteristics of HbA1c to predict persistent postpartum DM were calculated.

RESULTS

One hundred and twenty-one women met the study inclusion criteria. HbA1c was obtained at a median gestational age of 9 weeks. Twenty-two women (18.2%) had persistent postpartum DM, which was highly correlated with early HbA1c: 16 (73%) women had an elevated HbA1c, five (22.7%) women had a prediabetic HbA1c and only one (4.5%) woman had a normal HbA1c. Of 65 women with gestational DM and a normal early HbA1c, only one (1.5%) had persistent DM within the first year (negative predictive value 98.5%). Sixteen of 18 women with an elevated early HbA1c had persistent postpartum DM (positive predictive value 88.9%). These percentages were significant overall and between groups (p < 0.001). No clinical or demographic factors were highly predictive of postpartum DM.

CONCLUSIONS

Early pregnancy glycaemia, as measured by HbA1c at the first prenatal visit, is highly predictive of persistent postpartum DM, and may allow clinically important risk stratification to prioritize postpartum testing and care. Postpartum DM is rare amongst women with gestational DM who begin the pregnancy with a normal HbA1c, while postpartum DM is highly likely for those with an elevated HbA1c in early pregnancy. Nearly three-quarters of women who tested positive for DM post partum had an elevated HbA1c in early pregnancy, indicating that they had undiagnosed DM prior to conception.

Molecular biomarkers for gestational diabetes mellitus and postpartum diabetes

ABSTRACT

Gestational diabetes mellitus (GDM) is a growing public health problem worldwide that threatens both maternal and fetal health. Identifying individuals at high risk for GDM and diabetes after GDM is particularly useful for early intervention and prevention of disease progression. In the last decades, a number of studies have used metabolomics, genomics, and proteomic approaches to investigate associations between biomolecules and GDM progression. These studies clearly demonstrate that various biomarkers reflect pathological changes in GDM. The established markers have potential use as screening and diagnostic tools in GDM and in postpartum diabetes research. In the present review, we summarize recent studies of metabolites, single-nucleotide polymorphisms, microRNAs, and proteins associated with GDM and its transition to postpartum diabetes, with a focus on their predictive value in screening and diagnosis.

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.

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.

Clinical practice recommendations for the detection and management of hyperglycemia in pregnancy from South Asia, Africa and Mexico during COVID-19 pandemic

The human coronavirus disease 2019 (COVID-19) pandemic has affected overall healthcare delivery, including prenatal, antenatal and postnatal care. Hyperglycemia in pregnancy (HIP) is the most common medical condition encountered during pregnancy. There is little guidance for primary care physicians for providing delivery of optimal perinatal care while minimizing the risk of COVID-19 infection in pregnant women. This review aims to describe pragmatic modifications in the screening, detection and management of HIP during the COVID- 19 pandemic. In this review, articles published up to June 2021 were searched on multiple databases, including PubMed, Medline, EMBASE and ScienceDirect. Direct online searches were conducted to identify national and international guidelines. Search criteria included terms to extract articles describing HIP with and/or without COVID-19 between 1^st March 2020 and 15^th June 2021. Fasting plasma glucose, glycosylated hemoglobin (HbA1c) and random plasma glucose could be alternative screening strategies for gestational diabetes mellitus screening (at 24–28 weeks of gestation), instead of the traditional 2 h oral glucose tolerance test. The use of telemedicine for the management of HIP is recommended. Hospital visits should be scheduled to coincide with obstetric and ultrasound visits. COVID-19 infected pregnant women with HIP need enhanced maternal and fetal vigilance, optimal diabetes care and psychological support in addition to supportive measures. This article presents pragmatic options and approaches for primary care physicians, diabetes care providers and obstetricians for GDM screening, diagnosis and management during the pandemic, to be used in conjunction with routine antenatal care.

Evidence to support the classification of hyperglycemia first detected in pregnancy to predict diabetes 6-12 weeks postpartum: A single center cohort study

AIMS

Diagnostic criteria for type 2 diabetes mellitus (T2DM) applied to women with gestational diabetes mellitus (GDM) may predict postpartum T2DM but requires validation.

METHODS

Women with GDM aged ≥ 18-years were prospectively evaluated 6-12 weeks after delivery at Tygerberg Hospital, Cape Town, South-Africa (November 2015- December 2018). Glucose status at GDM diagnosis was categorized into i) International Association for Diabetes in Pregnancy Study Group (IADPSG) T2DM (fasting glucose ≥ 7 mmol/L and/or 2hr-glucose ≥ 11.1 mmol/L) or ii) modified National Institute for Care Excellence (NICE) GDM (fasting glucose ≥ 5.6 mmol/L-6.9 mmol/L and/or 2hr-glucose ≥ 7.8 mmol/L-11 mmol/L) and compared with postpartum OGTT.

RESULTS

IADPSG T2DM and NICE GDM was present in 35% (n = 64) and 65% (n = 117) of the 181 women who completed the 8 ± 2 weeks postpartum evaluation respectively. Postpartum, the prevalence of T2DM and prediabetes was 26% (n = 47/181) and 15% (n = 28). Antenatal IADPSG T2DM categorization identified 31/47 women with postpartum T2DM (sensitivity 75%; specificity 48%). All of the modified NICE GDM category women who developed T2DM (n = 16/117) had elevations of both fasting and 2hr-glucose values antenatally.

CONCLUSION

The utility of the IADPSG T2DM criteria to predict T2DM postpartum is confirmed. Women with both fasting and 2hr-glucose values above GDM cut-offs emerged as another high-risk category.

Utility of in-hospital post-delivery fasting plasma glucose to predict postpartum glucose status in women with hyperglycaemia first detected in pregnancy: A prospective cohort study

Background

Women with hyperglycaemia first detected in pregnancy (HFDP), including those with gestational diabetes mellitus (GDM), should undergo a glucose evaluation 4–12 weeks after delivery. Globally, suboptimal postpartum return rates limit the opportunity to intervene in women with sustained hyperglycaemia and pragmatic solutions should be sought to bridge this gap.

Objective

To assess the utility of postpartum in-hospital glucose evaluation to predict the outcome of the oral glucose tolerance test (OGTT) performed 4–12 weeks after delivery.

Methods

The study was performed prospectively at Tygerberg Hospital, Cape Town, South Africa. Women with HFDP, classified as GDM based on the modified National Institute for Health and Care Excellence criteria, who delivered between November 2018 and June 2019 were included in the study. Fasting plasma glucose (FPG) was performed 24–72 hours after delivery (t1) in the postnatal ward, provided glucose lowering medication was discontinued at delivery. An OGTT 4–12 weeks postpartum (t2) was scheduled for the total cohort. We compared glucose values and glucose categories at t1 and t2 and evaluated antenatal characteristics of women who returned, compared to the group that was lost to follow-up.

Results

In-hospital post-delivery glucose assessment (t1) was performed in 115 women. Glucose levels were significantly lower at t1 compared to antenatal diagnostic values (t0) and assessment at t2. Of the fourteen women with hyperglycaemia at t2, none had abnormal fasting glucose concentrations at t1. Women with HFDP who fulfilled criteria for overt diabetes at t0, all (24/115) had normal fasting glucose levels at t1 except for IFG in one (1/24). The antenatal characteristics of women with HFDP who returned at t2, were similar to the women who did not return.

Conclusion

Based on this study, in-hospital fasting glucose 24–72 hours postpartum cannot replace the OGTT 4–12 weeks postpartum. Pragmatic solutions for low postpartum return rates in women with HFDP should be pursued.

Risk factors associated with gestational diabetes mellitus: The role of pregnancy-induced hypertension and physical inactivity

BACKGROUND

Gestational diabetes mellitus (GDM) causes serious complications affecting the mother and fetus. Physical activity (PA) during pregnancy has positive effects on the mother and fetus. The objectives of this study were to assess GMD prevalence in Kuwait, identify its risk factors, and to evaluate its association with PA.

METHODS

A cross-sectional study was conducted among a randomly selected 653 post-partum women from all public maternal centers and five private centers. An anonymous self-administered questionnaire was used to collect participants' socio-demographic data, medical and obstetric history. Pregnancy Physical Activity Questionnaire (PPAQ) was used to assess PA level.

RESULTS

Participants' mean age was 30.1 ± 5.3. GMD was diagnosed among 14.1% (95% CI: 11.6-17.0) of participants. Binary logistic regression revealed that poor income, having 2 + chronic diseases, past history of GDM, hypothyroidism, high systolic or diastolic blood pressure during pregnancy were independently correlated with developing GDM. For physical activity, the overall means of PPAQ total and sub-scores were below average and only PPAQ sub-score -Vigorous Intensity Activity- was significantly higher amid women without GMD than those with. However, PPAQ mean scores showed significant positive correlation with women's pre-pregnancy BMI and birth weight; and a significant negative association with gestational systolic and diastolic blood pressure.

CONCLUSIONS

GDM prevalence is relatively high in Kuwait, notably amid expatriates. Pregnancy-induced hypertension along with social and pre-pregnancy medical conditions correlated with developing GDM. PA helped mitigated pregnancy blood pressure, and fetal birth weight. Promoting additional medical monitoring and PA during pregnancy might aid reduce the prevalence of GDM.