Paradigm Shifts in the Management of Diabetes in Pregnancy: The Importance of Type 2 Diabetes and Early Hyperglycemia in Pregnancy: The 2020 Norbert Freinkel Award Lecture

Despite treatment, HbA1c ≥ 37 mmol/mol in the first trimester is associated with premature delivery among South Asian women with gestational diabetes mellitus: a retrospective cohort study

PURPOSE

To examine the effects of first-trimester HbA1c (HbA1c-FT) ≥ 37 mmol/mol on preterm birth (PTB) and large-for-gestational-age (LGA) babies in a retrospective cohort of South Asian pregnant women with gestational diabetes (GDM).

METHODS

The cohort (n = 686) was separated into two groups based on HbA1c-FT values: Group A (n = 97) and Group B (n = 589), with values of 37-46 mmol/mol (5.5-6.4%) and < 37 mmol/mol (5.5%), respectively. HbA1c-FT's independent influence on PTB and LGA babies was examined using multivariable logistic regression in groups A and B women. The reference group (Group C) included 2031 non-GDM women with HbA1c-FT < 37 mmol/mol (< 5.5%). The effects of HbA1c-FT on PTB and LGA babies in obese women in Groups A, B, and C (designated as A-ob, B-ob, and C-ob, respectively) were re-analyzed using multivariable logistic regression.

RESULTS

Group A GDM women with greater HbA1c-FT had a higher risk for PTB (aOR:1.86, 95% CI:1.10-3.14) but not LGA babies (aOR:1.13, 95%: 0.70-1.83). The risk of PTB was higher for obese women in Group A-ob: aOR 3.28 [95% CI 1.68-6.39]. However, GDM women with normal HbA1c-FT exhibited no elevated risk for PTB: Groups B and B-ob had aORs of 1.30 (95% CI 0.86-1.98) and 1.28 (95% CI 0.88-1.85) respectively.

CONCLUSIONS

South Asian GDM women with prediabetic HbA1c FT; 37-46 mmol/mol (5.5-6.4%) are more likely to deliver preterm babies despite treatment, while the risk for LGA babies was the same as non-GDM women.

Epidemiology and management of gestational diabetes

Gestational diabetes is defined as hyperglycaemia first detected during pregnancy at glucose concentrations that are less than those of overt diabetes. Around 14% of pregnancies globally are affected by gestational diabetes; its prevalence varies with differences in risk factors and approaches to screening and diagnosis; and it is increasing in parallel with obesity and type 2 diabetes. Gestational diabetes direct costs are US$1·6 billion in the USA alone, largely due to complications including hypertensive disorders, preterm delivery, and neonatal metabolic and respiratory consequences. Between 30% and 70% of gestational diabetes is diagnosed in early pregnancy (ie, early gestational diabetes defined by hyperglycaemia before 20 weeks of gestation). Early gestational diabetes is associated with worse pregnancy outcomes compared with women diagnosed with late gestational diabetes (hyperglycaemia from 24 weeks to 28 weeks of gestation). Randomised controlled trials show benefits of treating gestational diabetes from 24 weeks to 28 weeks of gestation. The WHO 2013 recommendations for diagnosing gestational diabetes (one-step 75 gm 2-h oral glucose tolerance test at 24-28 weeks of gestation) are largely based on the Hyperglycemia and Adverse Pregnancy Outcomes Study, which confirmed the linear association between pregnancy complications and late-pregnancy maternal glycaemia: a phenomenon that has now also been shown in early pregnancy. Recently, the Treatment of Booking Gestational Diabetes Mellitus (TOBOGM) trial showed benefit in diagnosis and treatment of early gestational diabetes for women with risk factors. Given the diabesity epidemic, evidence for gestational diabetes heterogeneity by timing and subtype, and advances in technology, a life course precision medicine approach is urgently needed, using evidence-based prevention, diagnostic, and treatment strategies.

Design, rationale and protocol for Glycemic Observation and Metabolic Outcomes in Mothers and Offspring (GO MOMs): an observational cohort study

INTRODUCTION

Given the increasing prevalence of both obesity and pre-diabetes in pregnant adults, there is growing interest in identifying hyperglycaemia in early pregnancy to optimise maternal and perinatal outcomes. Multiple organisations recommend first-trimester diabetes screening for individuals with risk factors; however, the benefits and drawbacks of detecting glucose abnormalities more mild than overt diabetes in early gestation and the best screening method to detect such abnormalities remain unclear.

METHODS AND ANALYSIS

The goal of the Glycemic Observation and Metabolic Outcomes in Mothers and Offspring study (GO MOMs) is to evaluate how early pregnancy glycaemia, measured using continuous glucose monitoring and oral glucose tolerance testing, relates to the diagnosis of gestational diabetes (GDM) at 24-28 weeks' gestation (maternal primary outcome) and large-for-gestational-age birth weight (newborn primary outcome). Secondary objectives include relating early pregnancy glycaemia to other adverse pregnancy outcomes and comprehensively detailing longitudinal changes in glucose over the course of pregnancy. GO MOMs enrolment began in April 2021 and will continue for 3.5 years with a target sample size of 2150 participants.

ETHICS AND DISSEMINATION

GO MOMs is centrally overseen by Vanderbilt University's Institutional Review Board and an Observational Study Monitoring Board appointed by National Institute of Diabetes and Digestive and Kidney Diseases. GO MOMs has potential to yield data that will improve understanding of hyperglycaemia in pregnancy, elucidate better approaches for early pregnancy GDM screening, and inform future clinical trials of early GDM treatment.

TRIAL REGISTRATION NUMBER

NCT04860336.

Impact of COVID-19 on gestational diabetes pregnancy outcomes in the UK: A multicentre retrospective cohort study

OBJECTIVE

To determine the impact of implementing emergency care pathway(s) for screening, diagnosing and managing women with gestational diabetes (GDM) during COVID-19.

DESIGN

Retrospective multicentre cohort.

SETTING

Nine National Health Service (NHS) Hospital Trusts/Health boards in England and Scotland.

POPULATION

4915 women with GDM pre-pandemic (1 April 2018 to 31 March 2020), and 3467 women with GDM during the pandemic (1 May 2020 to 31 March 2021).

METHODS

We examined clinical outcomes for women with GDM prior to and during the pandemic following changes in screening methods, diagnostic testing, glucose thresholds and introduction of virtual care for monitoring of antenatal glycaemia.

MAIN OUTCOME MEASURES

Intervention at birth, perinatal mortality, large-for-gestational-age infants and neonatal unit admission.

RESULTS

The new diagnostic criteria more often identified GDM women who were multiparous, had higher body mass index (BMI) and greater deprivation, and less frequently had previous GDM (all p < 0.05). During COVID, these women had no differences in the key outcome measures. Of the women, 3% were identified with pre-existing diabetes at antenatal booking. Where OGTT continued during COVID, but virtual care was introduced, outcomes were also similar pre- and during the pandemic.

CONCLUSIONS

Using HbA1c and fasting glucose identified a higher risk GDM population during the pandemic but this had minimal impact on pregnancy outcomes. The high prevalence of undiagnosed pre-existing diabetes suggests that women with GDM risk factors should be offered HbA1c screening in early pregnancy.

Positive association between circulating Caveolin-1 and microalbuminuria in overt diabetes mellitus in pregnancy

AIMS

Mounting evidence has shown that caveolin-1 plays a pathological role in the progression of albuminuria. Our study aimed to provide clinical evidence showing whether circulating caveolin-1 levels were associated with microalbuminuria (MAU) in women with overt diabetes mellitus in pregnancy (ODMIP).

METHODS

A total of 150 pregnant women were enrolled in different groups, including 40 women with ODMIP and MAU (ODMIP + MAU), 40 women with ODMIP, and 70 women without ODMIP (Non-ODMIP). Plasma caveolin-1 levels were determined by ELISA. The presence of caveolin-1 in the human umbilical vein vascular wall was evaluated by immunohistochemical and western blot analysis, respectively. Albumin transcytosis across endothelial cells was measured using an established nonradioactive in vitro approach.

RESULTS

Significantly increased levels of plasma caveolin-1 were detected in ODMIP + MAU women. The Pearson's correlation analysis revealed a positive correlation between plasma caveolin-1 levels and Hemoglobin A1c (HbA1c %) as well as with MAU in the ODMIP + MAU group. Simultaneously, experimental knockdown or overexpression of caveolin-1 significantly decreased or increased the level of albumin transcytosis across both human and mouse glomerular endothelial cells (GECs), respectively.

CONCLUSIONS

Our data showed a positive association between plasma caveolin-1 levels and microalbuminuria in ODMIP + MAU.

Does fasting plasma glucose values 5.1-5.6 mmol/l in the first trimester of gestation a matter?

Objectives

The aim of the study was to investigate the effect of treatment on pregnancy outcomes among women who had fasting plasma glucose (FPG) 5.1-5.6 mmol/l in the first trimester of pregnancy.

Methods

We performed a secondary-analysis of a randomized community non-inferiority trial of gestational diabetes mellitus (GDM) screening. All pregnant women with FPG values range 5.1-5.6 mmol/l in the first trimester of gestation were included in the present study (n=3297) and classified to either the (i) intervention group who received treatment for GDM along with usual prenatal care (n=1,198), (ii) control group who received usual-prenatal-care (n=2,099). Macrosomia/large for gestational age (LGA) and primary cesarean-section (C-S) were considered as primary-outcomes. A modified-Poisson-regression for binary outcome data with a log link function and robust error variance was used to RR (95%CI) for the associations between GDM status and incidence of pregnancy outcomes.

Results

The mean maternal age and BMI of pregnant women in both study groups were similar. There were no statistically significant differences in the adjusted risks of adverse pregnancy outcomes, including macrosomia, primary C-S, preterm birth, hyperbilirubinemia, preeclampsia, NICU-admission, birth trauma, and LBW both groups.

Conclusions

It is found that treating women with first-trimester FPG values of 5.1-5.6 mmol/l could not improve adverse pregnancy outcomes including macrosomia, Primary C-S, Preterm birth, hypoglycemia, hypocalcemia, preeclampsia, NICU admission, Birth trauma and LBW. Therefore, extrapolating the FPG cut-off point of the second trimester to the first -which has been proposed by the IADPSG, might therefore not be appropriate.

Clinical Trial Registration

https://www.irct.ir/trial/518, identifier IRCT138707081281N1.

A Brazilian cohort of pregnant women with overt diabetes: analyses of risk factors using a machine learning technique

Objective

Pregnancy complicated by type 2 diabetes is rising, while data on type 2 diabetes first diagnosed in pregnancy (overt diabetes) are scarce. We aimed to describe the frequency and characteristics of pregnant women with overt diabetes, compare them to those with known pregestational diabetes, and evaluate the potential predictors for the diagnosis of overt diabetes.

Subjects and methods

A retrospective cohort study including all pregnant women with type 2 diabetes evaluated in two public hospitals in Porto Alegre, Brazil, from May 20, 2005, to June 30, 2021. Classic and obstetric factors associated with type 2 diabetes risk were compared between the two groups, using machine learning techniques and multivariable analysis with Poisson regression.

Results

Overt diabetes occurred in 33% (95% confidence interval: 29%-37%) of 646 women. Characteristics of women with known or unknown type 2 diabetes were similar; excessive weight was the most common risk factor, affecting ~90% of women. Age >30 years and positive family history of diabetes were inversely related to a diagnosis of overt diabetes, while previous delivery of a macrosomic baby behaved as a risk factor in younger multiparous women; previous gestational diabetes and chronic hypertension were not relevant risk factors.

Conclusion

Characteristics of women with overt diabetes are similar to those of women with pregestational diabetes. Classic risk factors for diabetes not included in current questionnaires can help identify women at risk of type 2 diabetes before they become pregnant.

Maternal prepregnancy obesity and gestational diabetes influence on adverse perinatal outcomes

Objective

Evaluate the influence of isolated and associated prepregnancy obesity and gestational diabetes mellitus (GDM) on adverse perinatal outcomes.

Materials and methods

Cross-sectional observational study with women who delivered at a Brazilian Maternity Hospital, between August and December 2020. Data were collected by interview with application form, and medical records. Sample was stratified by body mass index (BMI) and GDM screening in four groups: no obesity (BMI < 30 kg/m2) no GDM - reference; isolated GDM; isolated obesity (BMI ≥ 30 kg/m2); and obesity with GDM. Preeclampsia (PE), cesarean section (CS), large-for-gestational-age (LGA) newborn and admission to neonatal intensive care unit (NICU) were analyzed by odds ratio (OR) adjusted for confounding factors, adopting 95% confidence interval (CI) and P < 0.05 statistically significant.

Results

From 1,618 participants, isolated obesity group (233/14.40%) had high chance of PE (OR = 2.16; CI: 1.364-3.426; P = 0.001), isolated GDM group (190/11.74%) had high chance of CS (OR = 1.736; CI: 1.136-2.652; P = 0.011) and NICU admission (OR = 2.32; CI: 1.265-4.261; P = 0.007), and obesity with GDM group (121/7.48%) had high chance of PE (OR = 1.93; CI: 1.074-3.484; P = 0.028), CS (OR = 1.925; CI: 1.124-3.298; P = 0.017) and LGA newborn (OR = 1.81; CI: 1.027-3.204; P = 0.040), compared with reference (1,074/66.38%).

Conclusion

Obesity and GDM enhances the chance of different negative outcomes, worsening this prognosis when associated.

Treatment of Gestational Diabetes Mellitus Diagnosed Early in Pregnancy

BACKGROUND

Whether treatment of gestational diabetes before 20 weeks' gestation improves maternal and infant health is unclear.

METHODS

We randomly assigned, in a 1:1 ratio, women between 4 weeks' and 19 weeks 6 days' gestation who had a risk factor for hyperglycemia and a diagnosis of gestational diabetes (World Health Organization 2013 criteria) to receive immediate treatment for gestational diabetes or deferred or no treatment, depending on the results of a repeat oral glucose-tolerance test [OGTT] at 24 to 28 weeks' gestation (control). The trial included three primary outcomes: a composite of adverse neonatal outcomes (birth at <37 weeks' gestation, birth trauma, birth weight of ≥4500 g, respiratory distress, phototherapy, stillbirth or neonatal death, or shoulder dystocia), pregnancy-related hypertension (preeclampsia, eclampsia, or gestational hypertension), and neonatal lean body mass.

RESULTS

A total of 802 women underwent randomization; 406 were assigned to the immediate-treatment group and 396 to the control group; follow-up data were available for 793 women (98.9%). An initial OGTT was performed at a mean (±SD) gestation of 15.6±2.5 weeks. An adverse neonatal outcome event occurred in 94 of 378 women (24.9%) in the immediate-treatment group and in 113 of 370 women (30.5%) in the control group (adjusted risk difference, -5.6 percentage points; 95% confidence interval [CI], -10.1 to -1.2). Pregnancy-related hypertension occurred in 40 of 378 women (10.6%) in the immediate-treatment group and in 37 of 372 women (9.9%) in the control group (adjusted risk difference, 0.7 percentage points; 95% CI, -1.6 to 2.9). The mean neonatal lean body mass was 2.86 g in the immediate-treatment group and 2.91 g in the control group (adjusted mean difference, -0.04 g; 95% CI, -0.09 to 0.02). No between-group differences were observed with respect to serious adverse events associated with screening and treatment.

CONCLUSIONS

Immediate treatment of gestational diabetes before 20 weeks' gestation led to a modestly lower incidence of a composite of adverse neonatal outcomes than no immediate treatment; no material differences were observed for pregnancy-related hypertension or neonatal lean body mass. (Funded by the National Health and Medical Research Council and others; TOBOGM Australian New Zealand Clinical Trials Registry number, ACTRN12616000924459.).

Reducing Maternal Obesity and Diabetes Risks Prior to Conception with the National Diabetes Prevention Program

INTRODUCTION

Intrauterine exposure to maternal obesity and hyperglycemia greatly increases offspring health risks. Scalable lifestyle interventions to lower weight and glycemia prior to conception are needed, but have been understudied, especially in diverse and low-income women with disproportionately high risks of negative maternal-child outcomes. The objective of this report is to provide initial evidence of the National Diabetes Prevention Program's (NDPP) effects on maternal-child outcomes in diverse, low-income women and their offspring.

METHODS

The yearlong NDPP was delivered in a safety net healthcare system to 1,569 participants from 2013 to 2019. Using medical records, we evaluated outcomes for women < 40 years who became pregnant and delivered after attending the NDPP for ≥ 1 month (n = 32), as compared to a usual care group of women < 40 years (n = 26) who were initially eligible for the NDPP but were excluded due to pregnancy at enrollment.

RESULTS

Most women in either group were Latinx, had Medicaid or were uninsured, and had obesity at baseline. The mean difference in BMI change from baseline to conception was - 1.8 ± 0.6 kg/m² (p = 0.002) for NDPP versus usual care. Fewer NDPP participants had obesity at conception (56.7% vs. 88.0%, p = 0.011) and hyperglycemia in early pregnancy (4.0% vs. 25.0%; p = 0.020) than usual care. No other differences were statistically significant, yet nearly all outcomes favored the NDPP. Covariate-adjusted results were consistent, except the difference in frequency of obesity at conception was no longer significant (p = 0.132).

DISCUSSION

Results provide preliminary evidence that the NDPP may support a reduction in peri-conceptional obesity/diabetes risks among diverse and low-income women.

Diabetes in Pregnancy for Mothers and Offspring: Reflection on 30 Years of Clinical and Translational Research: The 2022 Norbert Freinkel Award Lecture

Hyperglycemia during pregnancy is a double-edged sword, affecting both mothers and their offspring and creating a vicious cycle that can affect multiple generations. Research in this field over the past 30 years has greatly improved our understanding of this disease and formed the basis of improved strategies to improve the health of mothers and their babies. Despite this progress, gestational and preexisting diabetes continue to have significant effects on both short- and long-term health of mothers and their offspring. In this article, I provide an overview of the work that my colleagues and I have done to advance the knowledge base around diabetes and pregnancy in four areas: 1) diabetes risk after gestational diabetes mellitus (GDM), including racial and ethnic disparities; 2) the pathophysiology of GDM and subsequent diabetes in Hispanic women; 3) diabetes prevention and β-cell preservation following GDM; and 4) evidence for multiple potential developmental effects in offspring that vary according to the timing of exposure and severity of maternal diabetes during pregnancy. This research continues the legacy of Norbert Freinkel and the concepts that he contributed to the field of diabetes and pregnancy. With the epidemic of obesity, increasing rates of type 1 and type 2 diabetes in youth, and rising prevalence of GDM across all racial and ethnic groups, we have a lot more work to do to combat this disease to break the vicious cycle.

Experiences of Preconception Counseling among Pregnant Women with Preexisting Diabetes: Opportunities to Improve Patient-Centered Care

Available research suggests that patients with diabetes do not regularly receive preconception counseling, but information on patients' experiences of counseling is scant. We conducted a qualitative study involving semi-structured interviews with 22 patients between October 2020 and February 2021. Pregnant patients with preexisting diabetes were recruited from a specialty diabetes and pregnancy clinic at a large academic medical center in Northern California. Interviews were transcribed, coded, and analyzed using an inductive and deductive content analysis approach. A total of 27% reported they did not have any pregnancy-related discussions with a health care provider before pregnancy. Of those that did, many sought out counseling; this was often connected to how "planned" the pregnancy was. Few participants, nearly all with type 1 diabetes, reported having a formal preconception care visit. Participants described receiving information mostly about the risks associated with diabetes and pregnancy. While participants who sought out counseling generally reported their providers were supportive of their desire for pregnancy, there were a few exceptions, notably all among patients with type 2 diabetes. The varied experiences of participants indicate gaps in the delivery of pre-pregnancy counseling to patients with diabetes and suggest counseling may vary based on diabetes type. There are opportunities to improve the patient-centeredness of counseling.

Fasting Plasma Glucose and Its Relationship to Anthropometric Phenotype in Women Diagnosed with Gestational Diabetes According to IADPSG Criteria

BACKGROUND

Gestational diabetes mellitus (GDM) is characterized by new-onset hyperglycemia in pregnancy. According to the International Association of Diabetes and Pregnancy Study Groups (IADPSG) recommendations, GDM may be diagnosed based on repeatedly increased fasting glucose levels in the first trimester, or later, the detection of increased fasting glucose and/or increased glucose levels during a 75 g oral glucose tolerance test (OGTT). The study aimed to assess whether differences may be found between women diagnosed with GDM by fasting glucose or glucose challenge tests in early or late pregnancy.

METHODS

The retrospective observational study enrolled 418 women diagnosed with GDM in accordance with the IADPSG criteria: early pregnancy fasting plasma glucose (FPG) ≥ 5.1 mmol/L; late pregnancy FPG ≥ 5.1 mmol/L (0 min) and/or postprandial plasma glucose (PPG) ≥ 10.0 mmol/L (60 min), PPG ≥ 8.5 mmol/L (120 min) 75 g OGTT. The analyses included anthropometric parameters at the beginning and during pregnancy, laboratory values of glycated hemoglobin, fructosamine, birth weight measures and the presence of neonatal complications.

RESULTS

There were significant differences in body weight (78.3 ± 19.1; 74.0 ± 16.7; 67.2 ± 15.7 kg) and body mass index (BMI) (27.9 ± 6.6; 26.4 ± 5.8; 24.4 ± 5.2 kg/m²) in early pregnancy. Differences were also found in gestational weight gain (9.3 ± 6.8 vs. 12.4 ± 6.9 vs. 11.1 ± 4.7 kg) and the need for insulin therapy (14.7%; 7.1%; 4.0%). The study revealed no difference in the presence of neonatal complications but differences in birth weight (3372.2 ± 552.2 vs. 3415.6 ± 529.0 vs. 3199.0 ± 560.5 g).

CONCLUSIONS

Gestational diabetes, characterized by FPG ≥ 5.1 mmol/L in early pregnancy, is associated with higher body weight and BMI at the beginning of pregnancy as well as with a higher risk for insulin therapy and increased birth weight.

Primary care nurse practitioner practices to lower type 2 diabetes risks in women with a history of gestational diabetes mellitus

BACKGROUND

Women with a gestational diabetes mellitus (GDM) history have increased lifetime type 2 diabetes (T2D) risk, with 16 times greater risk 3 to 6 years after the pregnancy, compared with women without GDM. Offspring from diabetes-complicated pregnancies also face increased health risks.

PURPOSE

The study purpose was to describe the primary care practices of nurse practitioners (NPs) aimed at reducing T2D-related health risks in women with a history of GDM.

METHODOLOGY

Florida-licensed primary care NPs (n = 47) completed a 57-item online survey that included an 8-item scale about recommended practices to reduce T2D risks for women with GDM history. Descriptive statistics, Chi Square test, and Fisher exact test were conducted.

RESULTS

Most (67%) participants "often/always" screened for T2D every 1-3 years per guidelines, but only 31.8% "often/always" advised about pregnancy planning/preconception T2D assessment. Compared with "none" or ≤2 hours of GDM care education, participants with >2 hours were more likely (p < .05) to "often/always" perform five recommended practices: 1) counsel about increased T2D risks; 2) educate about self-advocacy for T2D screening; 3) T2D screening every 1-3 years; 4) counsel about breastfeeding to reduce T2D risk; and 5) discuss postpartum weight loss and increased physical activity to lower T2D risk.

CONCLUSION

Findings indicate inconsistent care practices and suggest that >2 hours of education about care of women with GDM history may increase primary care NPs performing recommended practices to reduce T2D risks and prevent health problems for women and future offspring.

IMPLICATIONS

Nurse practitioner education is needed involving care of women with GDM history to mitigate risks for T2D.

Overt diabetes imposes a comparable burden on outcomes as pregestational diabetes: a cohort study

BACKGROUND

Women with diabetes first diagnosed during pregnancy (overt diabetes) may be at the same risk level of adverse outcomes as those with known pregestational diabetes. We compared pregnancy outcomes between these groups.

METHODS

We evaluated pregnant women with type 2 diabetes, pregestational or overt diabetes, attending high risk antenatal care in two public hospitals in Southern Brazil, from May 20, 2005 to June 30, 2021. Outcomes were retrieved from electronic medical records. Risk of adverse outcomes, expressed as relative risk (RR) and 95% confidence interval (CI), were calculated using Poisson regression with robust estimates.

RESULTS

Of 618 women, 33% were labelled as having overt diabetes and 67%, pregestational diabetes. Baseline maternal characteristics were similar: there was a slight, non-clinically relevant, difference in maternal age (33 ± 5.7 years in women with pregestational diabetes vs. 32 ± 6.0 years in women with overt diabetes, p = 0.004); and women with overt diabetes reported smoking almost twice compared to those with pregestational diabetes (12.3% vs. 6.5%, p = 0.024). There were no relevant differences between the groups regarding pregnancy outcomes, although there was a trend of higher neonatal intensive care admission in the group of women with pregestational diabetes (45.2% vs. 36.1%, p = 0.051).

CONCLUSIONS

Overt diabetes was diagnosed in one third of this cohort of pregnant women with hyperglycemia. Their pregnancy outcomes were similar to those of women with pregestational diabetes and were mostly related to maternal demographic characteristics and metabolic control. A call to action should be made to identify women of childbearing age at risk for pre-pregnancy diabetes; to detect hyperglycemia before conception; and to implement timely preconception care to all women with diabetes.

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.

Diet-Treated Gestational Diabetes Mellitus Is an Underestimated Risk Factor for Adverse Pregnancy Outcomes: A Swedish Population-Based Cohort Study

In Sweden, diet-treated gestational diabetes mellitus (GDM) pregnancies have been managed as low risk. The aim was to evaluate the risk of adverse perinatal outcomes among women with diet-treated GDM compared with the background population and with insulin-treated GDM. This is a population-based cohort study using national register data between 1998 and 2012, before new GDM management guidelines and diagnostic criteria in Sweden were introduced. Singleton pregnancies (n = 1,455,580) without pregestational diabetes were included. Among 14,242 (1.0%) women diagnosed with GDM, 8851 (62.1%) were treated with diet and 5391 (37.9%) with insulin. In logistic regression analysis, the risk was significantly increased in both diet- and insulin-treated groups (vs. background) for large-for-gestational-age newborns, preeclampsia, cesarean section, birth trauma and preterm delivery. The risk was higher in the insulin-treated group (vs. diet) for most outcomes, but perinatal mortality rates neither differed between treatment groups nor compared to the background population. Diet as a treatment for GDM did not normalize pregnancy outcomes. Pregnancies with diet-treated GDM should therefore not be considered as low risk. Whether changes in surveillance and treatment improve outcomes needs to be evaluated.

Effect of anemia and erythrocyte indices on hemoglobin A1c levels among pregnant women

BACKGROUND

Anemia is a common disorder among pregnant women; however, the effect of anemia on hemoglobin A1c (HbA1c) levels has not been adequately explored. We aim to examine the influence of anemia on the HbA1c concentration and investigate the relationship between erythrocyte indices and HbA1c levels during pregnancy.

METHODS

We performed a retrospective analysis of 1369 pregnant Chinese women. The clinical and analytical data were collected. Independent t-test and Analysis of Variance were used for comparative studies, and multiple linear regression analysis was used to identify the association between erythrocyte indices and HbA1c.

RESULTS

The differences in HbA1c between non-anemia and mild anemia were negligible, and the differences in HbA1c between non-anemia and moderate anemia were well within the allowable variability for clinical practice (≥0.5% absolute changes). Mean corpuscular hemoglobin (MCH) correlated with HbA1c significantly, independent of pregnancy, trimester, and anemia. The distinction of HbA1c levels between grades of Hb became no significant (P = 0.955), while differences between trimesters persisted after adjusting for MCH.

CONCLUSION

Mild and moderate anemia should not be the primary concern when using HbA1c to monitor blood glucose in pregnancy. MCH showed negative correlations with HbA1c independently, suggesting a previously unknown mechanism affecting HbA1c levels.

A Cluster Randomized Noninferiority Field Trial of Gestational Diabetes Mellitus Screening

CONTEXT

Although it is well-acknowledged that gestational diabetes mellitus (GDM) is associated with the increased risks of adverse pregnancy outcomes, the optimal strategy for screening and diagnosis of GDM is still a matter of debate.

OBJECTIVE

This study was conducted to demonstrate the noninferiority of less strict GDM screening criteria compared with the strict International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria with respect to maternal and neonatal outcomes.

METHODS

A cluster randomized noninferiority field trial was conducted on 35 528 pregnant women; they were scheduled to have 2 phases of GDM screening based on 5 different prespecified protocols including fasting plasma glucose in the first trimester with threshold of 5.1 mmol/L (92 mg/dL) (protocols A, D) or 5.6 mmol/L (100 mg/dL) (protocols B, C, E) and either a 1-step (GDM is defined if one of the plasma glucose values is exceeded [protocol A and C] or 2 or more exceeded values are needed [protocol B]) or 2-step approach (protocols D, E) in the second trimester. Guidelines for treatment of GDM were consistent with all protocols. Primary outcomes of the study were the prevalence of macrosomia and primary cesarean section (CS). The null hypothesis that less strict protocols are inferior to protocol A (IADPSG) was tested with a noninferiority margin effect (odds ratio) of 1.7.

RESULTS

The percentages of pregnant women diagnosed with GDM and assigned to protocols A, B, C, D, and E were 21.9%, 10.5%, 12.1%, 19.4%, and 8.1%, respectively. Intention-to-treat analyses satisfying the noninferiority of the less strict protocols of B, C, D, and E compared with protocol A. However, noninferiority was not shown for primary CS comparing protocol E with A. The odds ratios (95% CI) for macrosomia and CS were: B (1.01 [0.95-1.08]; 0.85 [0.56-1.28], C (1.03 [0.73-1.47]; 1.16 [0.88-1.51]), D (0.89 [0.68-1.17]; 0.94 [0.61-1.44]), and E (1.05 [0.65-1.69]; 1.33 [0.82-2.00]) vs A. There were no statistically significant differences in the adjusted odds of adverse pregnancy outcomes in the 2-step compared with the 1-step screening approaches, considering multiplicity adjustment.

CONCLUSIONS

The IADPSG GDM definition significantly increased the prevalence of GDM diagnosis. However, the less strict approaches were not inferior to other criteria in terms of adverse maternal and neonatal outcomes.

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.