The treatment of booking gestational diabetes mellitus (TOBOGM) pilot randomised controlled trial

The effects of gestational diabetes mellitus on fetal growth: is it different for low-risk and medium-high-risk pregnant women?

BACKGROUND

It has been suggested that gestational diabetes mellitus (GDM) alters the growth trajectory of a fetus and increases the risk of abnormal birth weight. In spite of this, there is still a significant debate regarding the mode and optimal timing of diagnosing this condition. Our aim was to determine fetal growth velocity and birth biometry in pregnant women with GDM at varying risk levels.

METHODS

We conducted a cohort study involving 1023 pregnant women at a maternity hospital in Ma'anshan, China. All women completed an oral glucose tolerance test at 24-28 weeks' gestation. We measured fetal head circumference (HC), femoral length (FL), abdominal circumference (AC), biparietal diameter (BPD), and estimate fetal weight (EFW) by ultrasound at 17, 24, 31, and 35 weeks' gestation, respectively.

RESULTS

Overall, 5115 ultrasound scans were performed. Among both low-risk and medium-high-risk pregnant women at 17-24 weeks' gestation, GDM exposure was associated with an increase in fetal growth velocity. Neonates born to women with GDM at medium-high risk had significantly larger birth weights than those born to women without GDM, while this was not observed in women at low risk.

CONCLUSION

In medium-high-risk pregnant women, exposure to GDM has a greater effect on the fetus, leading to abnormal fetal growth velocity that lasts beyond week 24. It is evident from our results that the effects of GDM on fetal growth differ between medium-high-risk pregnant women and low-risk pregnant women, and therefore a different screening program based on the risk factor for GDM is warranted.

Earlier detection of gestational diabetes impacts on medication requirements, neonatal and maternal outcomes

AIM

Gestational diabetes (GD) is a global health concern with significant implications for maternal and neonatal outcomes. This study investigates the association between early GD (eGD) diagnosis (<24 weeks), pharmacotherapy requirements and adverse neonatal outcomes.

MATERIALS AND METHODS

A cohort of 369 pregnant women underwent a 75-g oral glucose tolerance test. Maternal variables, pharmacotherapy prescriptions and neonatal outcomes were analysed employing t-tests, χ2 tests, and logistic regression. A p < .05 was considered significant.

RESULTS

Early GD increased the odds of neonatal hypoglycaemia [odds ratio (OR): 18.57, p = .013] and respiratory distress syndrome (OR: 4.75, p = .034). Nutritional therapy prescription by an accredited nutritionist was the most common treatment in women diagnosed after 24 weeks, but those with eGD required more frequently specialized nutritional consulting + metformin to achieve glycaemic control (p = .027). eGD was associated with a higher requirement of nutritional therapy prescription + metformin (OR: 2.26, 95% confidence interval: 1.25-4.09, p = .007) and with maternal hyperglycaemia during the post-partum period at 2 h of the oral glucose tolerance test (OR: 1.03, 95% confidence interval: 1.02-1.13, p = .024).

CONCLUSION

Timely diagnosis and personalized treatment of GD are desirable because an earlier presentation is related to a higher risk of adverse neonatal and maternal outcomes.

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.

Time to Move Beyond a Binary Criterion for Gestational Diabetes?

Over the years, several international guidelines have been developed by specialist organizations for the diagnosis of gestational diabetes mellitus (GDM). However, these guidelines vary and lack consensus on what level of glycemia defines GDM and worryingly, there is now evidence of over- or- under-diagnosis of women with GDM by current criteria. Towards this end, the National Priorities Research Program (NPRP) funded a program of research aimed at elucidating the problem with GDM diagnosis. It was determined, on completion of the project, that the solution required diagnosis of graded levels of dysglycemia in pregnancy and not just a diagnosis of presence or absence of GDM. A new diagnostic criterion (called the NPRP criterion) was created based on a single numerical summary of the three readings from the oral glucose tolerance test (GTT) that diagnosed women in pregnancy into four levels: normal, impaired, GDM and high risk GDM. This paper now examines existing GDM criteria vis-à-vis the NPRP criterion. It is noted that no significant change has happened over the years for existing criteria except for a gradual reduction in the threshold values of individual time-points or the number of time points, bringing us towards over-diagnosis of GDM in pregnancy. The new criterion unifies all readings from the GTT into one numerical value and, because it results in four levels of glycemia, represents a new way forwards for GDM diagnosis and can potentially reduce the rates of under diagnosis and over diagnosis of GDM.

Cost-effectiveness of diagnosis and treatment of early gestational diabetes mellitus: economic evaluation of the TOBOGM study, an international multicenter randomized controlled trial

Background

A recently undertaken multicenter randomized controlled trial (RCT) "Treatment Of BOoking Gestational diabetes Mellitus" (TOBOGM: 2017-2022) found that the diagnosis and treatment of pregnant women with early gestational diabetes mellitus (GDM) improved pregnancy outcomes. Based on data from the trial, this study aimed to assess the cost-effectiveness of diagnosis and treatment of early GDM (from <20 weeks') among women with risk factors for hyperglycemia in pregnancy compared with usual care (no treatment until 24-28 weeks') from a healthcare perspective.

Methods

Participants' healthcare resource utilization data were collected from their self-reported questionnaires and hospital records, and valued using the unit costs obtained from standard Australian national sources. Costs were reported in US dollars ($) using the purchasing power parity (PPP) estimates to facilitate comparison of costs across countries. Intention-to-treat (ITT) principle was followed. Missing cost data were replaced using multiple imputations. Bootstrapping method was used to estimate the uncertainty around mean cost difference and cost-effectiveness results. Bootstrapped cost-effect pairs were used to plot the cost-effectiveness (CE) plane and cost-effectiveness acceptability curve (CEAC).

Findings

Diagnosis and treatment of early GDM was more effective and tended to be less costly, i.e., dominant (cost-saving) [-5.6% composite adverse pregnancy outcome (95% CI: -10.1%, -1.2%), -$1373 (95% CI: -$3,749, $642)] compared with usual care. Our findings were confirmed by both the CE plane (88% of the bootstrapped cost-effect pairs fall in the south-west quadrant), and CEAC (the probability of the intervention being cost-effective ranged from 84% at a willingness-to-pay (WTP) threshold value of $10,000-99% at a WTP threshold value of $100,000 per composite adverse pregnancy outcome prevented). Sub-group analyses demonstrated that diagnosis and treatment of early GDM among women in the higher glycemic range (fasting blood glucose 95-109 mg/dl [5.3-6.0 mmol/L], 1-h blood glucose ≥191 mg/dl [10.6 mmol/L] and/or 2-h blood glucose 162-199 mg/dl [9.0-11.0 mmol/L]) was more effective and less costly (dominant) [-7.8% composite adverse pregnancy outcome (95% CI: -14.6%, -0.9%), -$2795 (95% CI: -$6,638, -$533)]; the intervention was more effective and tended to be less costly [-8.9% composite adverse pregnancy outcome (95% CI: -15.1%, -2.6%), -$5548 (95% CI: -$16,740, $1547)] among women diagnosed before 14 weeks' gestation as well.

Interpretation

Our findings highlight the potential health and economic benefits from the diagnosis and treatment of early GDM among women with risk factors for hyperglycemia in pregnancy and supports its implementation. Long-term follow-up studies are recommended as a key future area of research to assess the potential long-term health benefits and economic consequences of the intervention.

Funding

National Health and Medical Research Council (grants 1104231 and 2009326), Region O¨rebro Research Committee (grants Dnr OLL-970566 and OLL-942177), Medical Scientific Fund of the Mayor of Vienna (project 15,205 and project 23,026), South Western Sydney Local Health District Academic Unit (grant 2016), and Western Sydney University Ainsworth Trust Grant (2019).

Maternal-placental axis and its impact on fetal outcomes, metabolism, and development

Maternal obesity could impact offspring's health. During "critical period" such as pregnancy insults have a significant role in developing chronic diseases later in life. Literature has shown that diet can play a major role in essential metabolic and development processes on fetal outcomes. Moreover, the placenta, an essential organ developed in pregnancy, seems to have its functions impaired based on pre-gestational and gestational nutritional status. Specifically, a high-fat diet has been shown as a potential nutritional insult that also affects the maternal-placental axis, which is involved in offspring development and outcome. Moreover, some classes of nutrients are associated with pregnancy complications such as reduced intake of micronutrients and diabetes, preeclampsia, and preterm delivery. Thus, we will summarize the current literature on maternal environment factors that impacts the placental development and consequently the fetal an offspring health, or the maternal-placental axis, and this on fetal outcomes, metabolism, and development.

Various screening and diagnosis approaches for gestational diabetes mellitus and adverse pregnancy outcomes: a secondary analysis of a randomized non-inferiority field trial

INTRODUCTION

We evaluate which screening and diagnostic approach resulted in the greatest reduction in adverse pregnancy outcomes due to increased treatment.

RESEARCH DESIGN AND METHODS

This study presents a secondary analysis of a randomized community non-inferiority trial conducted among pregnant women participating in the GULF Study in Iran. A total of 35 430 pregnant women were randomly assigned to one of the five prespecified gestational diabetes mellitus (GDM) screening protocols. The screening methods included fasting plasma glucose (FPG) in the first trimester and either a one-step or a two-step screening method in the second trimester of pregnancy. According to the results, participants were classified into 6 groups (1) First-trimester FPG: 100-126 mg/dL, GDM diagnosed at first trimester; (2) First trimester FPG: 92-99.9 mg/dL, GDM diagnosed at first trimester; (3) First trimester FPG: 92-99.9 mg/dL, GDM diagnosed at second trimester; (4) First trimester FPG: 92-99.9 mg/dL, healthy at second trimester; (5) First trimester FPG<92 mg/dL, GDM diagnosed at second trimester; (6) First trimester FPG<92 mg/dL, healthy at second trimester. For our analysis, we initially used group 6, as the reference and repeated the analysis using group 2, as the reference group. The main outcome of the study was major adverse maternal and neonatal outcomes.

RESULTS

Macrosomia and primary caesarean section occurred in 9.8% and 21.0% in group 1, 7.8% and 19.8% in group 2, 5.4% and 18.6% in group 3, 6.6% and 21.5% in group 4, 8.3% and 24.0% in group 5, and 5.4% and 20.0% in group 6, respectively. Compared with group 6 as the reference, there was a significant increase in the adjusted risk of neonatal intensive care unit (NICU) admission in groups 1, 3, and 5 and an increased risk of macrosomia in groups 1, 2, and 5. Compared with group 2 as the reference, there was a significant decrease in the adjusted risk of macrosomia in group 3, a decreased risk of NICU admission in group 6, and an increased risk of hyperglycemia in group 3.

CONCLUSIONS

We conclude that screening approaches for GDM reduced the risk of adverse pregnancy outcomes to the same or near the same risk level of healthy pregnant women, except for the risk of NICU admission that increased significantly in groups diagnosed with GDM compared with healthy pregnant women. Individuals with slight increase in FPG (92-100 mg/dL) at first trimester, who were diagnosed as GDM, had an even increased risk of macrosomia in comparison to those group of women with FPG 92-100 mg/dL in the first trimester, who were not diagnosed with GDM, and developed GDM in second trimester TRIAL REGISTRATION: IRCT138707081281N1 (registered: February 15, 2017).

Complications and risk factors of early-onset versus late-onset gestational diabetes mellitus: A cohort study from Saudi Arabia

OBJECTIVES

To contribute to this discussion by comparing the complications associated with early-diagnosed versus (vs.) late-diagnosed gestational diabetes mellitus (GDM) for mothers and infants in order to provide baseline data that might guide future changes in the current recommendations for screening.

METHODS

The study compares the risk factors and complications for early- vs. late-diagnosed GDM in a cohort from Saudi Arabia. Prenatal, perinatal, postpartum, and neonatal variables were compared between the early vs. late-diagnosed GDM groups using information gathered from the patient's hospital records.

RESULTS

Significant predictors of early-diagnosed GDM included pregestational BMI and GDM history. Additionally, early diagnosis of GDM was linked to a higher incidence of pre-eclampsia and intrauterine fetal death. Women with early-diagnosed GDM also required more glycemic control interventions, like administering insulin and metformin and controlling their diet. The fetal birth weight and postpartum BMI were significantly higher in the early onset GDM group. The need for insulin and pre-eclampsia were significant factors linked to an early diagnosis of GDM, according to a logistic regression analysis.

CONCLUSION

Therefore, the current findings emphasize the need for early screening in pregnant women with high pregestational BMI and a history of GDM and show that those with early-onset GDM more likely to need insulin therapy and be at a higher risk of developing pre-eclampsia.

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.

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.).

Impact of gestational diabetes mellitus treatment on medium/long-term outcomes after pregnancy: A systematic review and meta-analysis

AIM

We aimed to evaluate the effect of gestational diabetes mellitus (GDM) treatment on medium/long-term outcomes both the mother and offspring.

METHODS

We performed a systematic review on randomized clinical trials addressing specific treatment of women with GDM versus usual care and its impact on maternal and offspring outcomes at medium/long-term. MEDLINE, EMBASE and CENTRAL were searched from inception to 8 October 2021.

OUTCOME VARIABLES

maternal (diabetes, metabolic syndrome, 12 secondary); offspring (diabetes, impaired fasting glucose, impaired glucose tolerance, high body mass index, 15 secondary). Risk of bias was assessed with Cochrane tool and aggregation performed with Revman 5.4.

RESULTS

We included five studies (1140 women, 767 offspring) with follow-up ranging 4-16 years after delivery. GDM treatment likely does not reduce risk of maternal diabetes (RR 1.00; [95% CI 0.82-1.23]) and may not reduce that of metabolic syndrome (RR 0.93; [95% CI 0.71-1.22]). We obtained very uncertain evidence that treatment may increase maternal HDL-cholesterol. Findings showed that GDM treatment may not have an impact on infants' outcomes (RRs 0.79; [95% CI 0.39-1.69] for impaired fasting glucose; RR 0.91; [95% CI 0.74-1.12] for body mass index >85th centile and 0.89; [95% CI 0.65-1.22] for body mass index >95th centile respectively).

CONCLUSIONS

With current evidence is uncertain if specific treatment of women with GDM has an impact on medium/long-term metabolic outcomes either in the mother or in the offspring. These results add evidence to the recommendation of systematically reevaluating mother and offspring after delivery.

REGISTRATION

OSF, DOI 10.17605/OSF.IO/KFN79.

Early screening for gestational diabetes mellitus: a meta-analysis of randomized controlled trials

OBJECTIVE

Current evidence is conflicting on whether early screening and treatment for gestational diabetes mellitus improve pregnancy outcomes. Thus, this systematic review and meta-analysis of randomized controlled trials aimed to assess the rate of adverse pregnancy outcomes among participants with early screening and treatment for gestational diabetes mellitus vs those with routine care.

DATA SOURCES

A systematic review of the literature was conducted using MEDLINE, Scopus, ClinicalTrials.gov, EMBASE, ScienceDirect, the Cochrane Library at the Central Register of Controlled Trials, and SciELO from inception to November 2021.

STUDY ELIGIBILITY CRITERIA

Studies were eligible for inclusion if they described randomized controlled trials comparing early screening with routine care for gestational diabetes mellitus to assess the effects of early screening and treatment on pregnancy outcomes.

METHODS

All randomized controlled trials comparing early vs standard screening of gestational diabetes mellitus assessing the effect of early screening (defined as a screening at <20 weeks of gestation) vs routine screening (defined as a screening at ≥20 weeks of gestation) on pregnancy outcomes were included. The primary outcome was defined as large for gestational age, as defined by the trial. The secondary maternal and neonatal outcomes were also evaluated. Subgroup analyses were performed on the basis of screening strategy and methods.

RESULTS

After exclusion, 8 randomized clinical trials (1920 participants) of early screening and treatment vs standard care were included. There were a total of 746 participants with early gestational diabetes mellitus. The risk of large for gestational age at birth did not differ between early screening and treatment for gestational diabetes mellitus and routine care among all included trials (8.1 vs 9.0%; relative risk, 0.94; 95% confidence interval, 0.73-1.22). Trials with a protocol of universal screening of participants at their first prenatal visit (>80% screened with HbA1c) and receiving early treatment if the screening test returned positive had a lower risk of large for gestational age (2.3 vs 9.1%; relative risk, 0.29; 95% confidence interval, 0.09-0.90) than those who had routine screening and care.

CONCLUSION

Overall, early screening and treatment of gestational diabetes mellitus did not reduce the risk of large for gestational age at birth. However, trials that screened all participants at their first visit and treated early, most for an HbA1c of 5.7% to 6.4%, had a reduced risk of large for gestational age at birth compared with routine care, suggesting a possible benefit of screening all pregnant patients. However, future well-designed trials are needed to confirm these findings.

Gestational Diabetes Mellitus—Recent Literature Review

Gestational diabetes mellitus (GDM), which is defined as a state of hyperglycemia that is first recognized during pregnancy, is currently the most common medical complication in pregnancy. GDM affects approximately 15% of pregnancies worldwide, accounting for approximately 18 million births annually. Mothers with GDM are at risk of developing gestational hypertension, pre-eclampsia and termination of pregnancy via Caesarean section. In addition, GDM increases the risk of complications, including cardiovascular disease, obesity and impaired carbohydrate metabolism, leading to the development of type 2 diabetes (T2DM) in both the mother and infant. The increase in the incidence of GDM also leads to a significant economic burden and deserves greater attention and awareness. A deeper understanding of the risk factors and pathogenesis becomes a necessity, with particular emphasis on the influence of SARS-CoV-2 and diagnostics, as well as an effective treatment, which may reduce perinatal and metabolic complications. The primary treatments for GDM are diet and increased exercise. Insulin, glibenclamide and metformin can be used to intensify the treatment. This paper provides an overview of the latest reports on the epidemiology, pathogenesis, diagnosis and treatment of GDM based on the literature.

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.

Early pregnancy hyperglycaemia as a significant predictor of large for gestational age neonates

AIMS

We aimed to determine the effect of early pregnancy hyperglycaemia on having a large for gestational age (LGA) neonate.

METHODS

A prospective cohort study was conducted among pregnant women in their first trimester. One-step plasma glucose (PG) evaluation procedure was performed to assess gestational diabetes mellitus (GDM) and diabetes mellitus (DM) in pregnancy as defined by the World Health Organization (WHO) criteria with International Association of Diabetes in Pregnancy Study Group (IADPSG) thresholds. The main outcome studied was large for gestational age neonates (LGA).

RESULTS

A total of 2,709 participants were recruited with a mean age of 28 years (SD = 5.4) and a median gestational age (GA) of eight weeks (interquartile range [IQR] = 2). The prevalence of GDM in first trimester (T1) was 15.0% (95% confidence interval [CI] = 13.7-16.4). Previously undiagnosed DM was detected among 2.5% of the participants. Out of 2,285 live births with a median delivery GA of 38 weeks (IQR = 3), 7.0% were LGA neonates. The cumulative incidence of LGA neonates in women with GDM and DM was 11.1 and 15.5 per 100 women, respectively. The relative risk of having an LGA neonate among women with DM and GDM was 2.30 (95% CI = 1.23-4.28) and 1.80 (95% CI = 1.27-2.53), respectively. The attributable risk percentage of a LGA neonate for hyperglycaemia was 15.01%. T1 fasting PG was significantly correlated with both neonatal birth weight and birth weight centile.

CONCLUSIONS

The proposed WHO criteria for hyperglycaemia in pregnancy are valid, even in T1, for predicting LGA neonates. The use of IADPSG threshold for Fasting PG, for risk assessment in early pregnancy in high-risk populations is recommended.

Cardiometabolic and Mental Health in Women With Early Gestational Diabetes Mellitus: A Prospective Cohort Study

CONTEXT

Early diagnosis and treatment of gestational diabetes (GDM) may reduce adverse obstetric and neonatal outcomes, especially in high-risk women. However, there is a lack of data for other outcomes.

OBJECTIVE

We compared cardiometabolic and mental health outcomes in women with early (eGDM) and classical (cGDM) GDM.

METHODS

This prospective cohort included 1185 All women with cGDM and 76 women with eGDM. The eGDM group had GDM risk factors (BMI >30 kg/m2, family history of diabetes, history of GDM, ethnicity), were tested at <20 weeks gestational age, and diagnosed using American Diabetes Association prediabetes criteria. All women underwent lifestyle adaptations. Obstetric, neonatal, mental, and cardiometabolic outcomes were assessed during pregnancy and postpartum.

RESULTS

The eGDM group had lower gestational weight gain than cGDM (10.7 ± 6.2 vs 12.6 ± 6.4; P = 0.03) but needed more medical treatment (66% vs 42%; P < 0.001). They had similar rates of adverse maternal and neonatal outcomes, except for increased large-for-gestational-age infants (25% vs 15%; P = 0.02). Mental health during pregnancy and postpartum did not differ between groups. eGDM had more atherogenic postpartum lipid profile than cGDM (P ≤ 0.001). In eGDM, the postpartum prevalence of the metabolic syndrome (MetS) was 1.8-fold, prediabetes was 3.1-fold, and diabetes was 7.4-fold higher than cGDM (waist circumference-based MetS: 62% vs 34%/BMI-based MetS: 46% vs 24%; prediabetes: 47.5% vs 15.3%; diabetes: 11.9% vs 1.6%, all P < 0.001). These differences remained unchanged after adjusting for GDM risk factors.

CONCLUSION

Compared with cGDM, eGDM was not associated with differences in mental health, but with increased adverse cardiometabolic outcomes, independent of GDM risk factors and gestational weight gain. This hints to a preexisting risk profile in eGDM.

Fetal abdominal overgrowth is already present at 20-24 gestational weeks prior to diagnosis of gestational diabetes mellitus

Fetal abdominal obesity (FAO) was detected at the time of gestational diabetes mellitus (GDM) diagnosis at 24–28 gestational weeks (GW) in older (≥ 35 years) and/or obese (≥ body mass index 25 kg/m²) women and persisted until delivery. We investigated whether FAO is already present at 20–24 GW. Medical records of 7820 singleton pregnancy including 384 GDM were reviewed. Fetal abdominal overgrowth was assessed by the fetal abdominal overgrowth ratios (FAORs) of the ultrasonographically estimated gestational age (GA) of abdominal circumference per actual GA by the last menstruation period, biparietal diameter or femur length, respectively. FAO was defined as FAOR ≥ 90th percentile. FAORs measured at 20–24 GW in older and/or obese but not in young and non-obese GDM subjects were significantly higher than those in NGT subjects. Relative to NGT subjects without FAO at 20–24 GW, odds ratios for exhibiting FAO at GDM diagnosis and large for gestational age in GDM with FAO at 20–24 GW were 10.15 and 5.57, and their primary cesarean delivery rate was significantly higher than those in GDM without FAO (44% vs. 29%). Earlier diagnosis and active interventions of GDM well before 20–24 GW might be necessary to prevent FAO in the older and/or obese women.

Early Gestational Diabetes Mellitus: Diagnostic Strategies and Clinical Implications

Preexisting diabetes mellitus (DM) should be ruled out early in pregnancy in those at risk. During screening, a significant proportion of women do not reach the threshold for overt DM but fulfill the criteria used for diagnosing conventional gestational DM (cGDM). There is no consensus on the management of pregnancies with intermediate levels of hyperglycemia thus diagnosed. We have used the term early gestational DM (eGDM) for this condition and reviewed the currently available literature. Fasting plasma glucose (FPG), oral glucose tolerance test, and glycated hemoglobin (HbA1c) are the commonly employed screening tools in early pregnancy. Observational studies suggest that early pregnancy FPG and Hba1c correlate with the risk of cGDM and adverse perinatal outcomes. However, specific cut-offs, including those proposed by the International Association of the Diabetes and Pregnancy Study Group, do not reliably predict the development of cGDM. Emerging data, though indicate that FPG ≥ 92 mg/dL (5.1 mmol/L), even in the absence of cGDM, signals the risk for perinatal complication. Elevated HbA1c, especially a level ≥ 5.9%, also correlates with the risk of cGDM and worsened outcome. HbA1c as a diagnostic test is however besieged with the usual caveats that occur in pregnancy. The studies that explored the effects of intervention present conflicting results, including a possibility of fetal malnutrition and small-for-date baby in the early treatment group. Diagnostic thresholds and glycemic targets in eGDM may differ, and large multicenter randomized controlled trials are necessary to define the appropriate strategy.

Screening for Gestational Diabetes: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Gestational diabetes is associated with several poor health outcomes.

OBJECTIVE

To update the 2012 review on screening for gestational diabetes to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, EMBASE, and CINAHL (2010 to May 2020), ClinicalTrials.gov, reference lists; surveillance through June 2021.

STUDY SELECTION

English-language intervention studies for screening and treatment; observational studies on screening; prospective studies on screening test accuracy.

DATA EXTRACTION AND SYNTHESIS

Dual review of titles/abstracts, full-text articles, and study quality. Single-reviewer data abstraction with verification. Random-effects meta-analysis or bivariate analysis (accuracy).

MAIN OUTCOMES AND MEASURES

Pregnancy, fetal/neonatal, and long-term health outcomes; harms of screening; accuracy.

RESULTS

A total of 76 studies were included (18 randomized clinical trials [RCTs] [n = 31 241], 2 nonrandomized intervention studies [n = 190], 56 observational studies [n = 261 678]). Direct evidence on benefits of screening vs no screening was limited to 4 observational studies with inconsistent findings and methodological limitations. Screening was not significantly associated with serious or long-term harm. In 5 RCTs (n = 25 772), 1-step (International Association of Diabetes and Pregnancy Study Group) vs 2-step (Carpenter and Coustan) screening was significantly associated with increased likelihood of gestational diabetes (11.5% vs 4.9%) but no improved health outcomes. At or after 24 weeks of gestation, oral glucose challenge tests with 140- and 135-mg/dL cutoffs had sensitivities of 82% and 93%, respectively, and specificities of 82% and 79%, respectively, against Carpenter and Coustan criteria, and a test with a 140-mg/dL cutoff had sensitivity of 85% and specificity of 81% against the National Diabetes Group Data criteria. Fasting plasma glucose tests with cutoffs of 85 and 90 mg/dL had sensitivities of 88% and 81% and specificities of 73% and 82%, respectively, against Carpenter and Coustan criteria. Based on 8 RCTs and 1 nonrandomized study (n = 3982), treatment was significantly associated with decreased risk of primary cesarean deliveries (relative risk [RR], 0.70 [95% CI, 0.54-0.91]; absolute risk difference [ARD], 5.3%), shoulder dystocia (RR, 0.42 [95% CI, 0.23-0.77]; ARD, 1.3%), macrosomia (RR, 0.53 [95% CI, 0.41-0.68]; ARD, 8.9%), large for gestational age (RR, 0.56 [95% CI, 0.47-0.66]; ARD, 8.4%), birth injuries (odds ratio, 0.33 [95% CI, 0.11-0.99]; ARD, 0.2%), and neonatal intensive care unit admissions (RR, 0.73 [95% CI, 0.53-0.99]; ARD, 2.0%). The association with reduction in preterm deliveries was not significant (RR, 0.75 [95% CI, 0.56-1.01]).

CONCLUSIONS AND RELEVANCE

Direct evidence on screening vs no screening remains limited. One- vs 2-step screening was not significantly associated with improved health outcomes. At or after 24 weeks of gestation, treatment of gestational diabetes was significantly associated with improved health outcomes.

Gestational diabetes: Implications for fetal growth, intervention timing, and treatment options

Maternal gestational diabetes mellitus (GDM) is one of the most common medical complications of pregnancy, which can adversely affect the short- and long-term health of mothers and newborns. In recent years, several studies have revealed the early impact of maternal hyperglycemia on fetal growth trajectory and birth weight abnormalities in GDM-exposed pregnancies. However, an intense debate continues regarding the mode and optimal timing of diagnosis and treatment of this condition. The purpose of this review is to provide a brief overview of the understanding of GDM and its implications for fetal growth, addressing the modulatory role of medical nutrition therapy and available pharmacological antidiabetic agents (i.e. insulin, metformin, and glyburide), and to identify gaps in current knowledge toward which future research should be directed.

An Update on Screening Strategies for Gestational Diabetes Mellitus: A Narrative Review

Gestational diabetes mellitus (GDM) is a frequent medical complication during pregnancy. Screening and diagnostic practices for GDM are inconsistent across the world. This narrative review includes data from 87 observational studies and randomized controlled trials (RCTs), and aims to give an overview of the current evidence on screening strategies and diagnostic criteria for GDM. Screening in early pregnancy remains controversial and studies show conflicting results on the benefit of screening and treatment of GDM in early pregnancy. Implementing the one-step "International Association of Diabetes and Pregnancy Study Groups" (IADPSG) screening strategy at 24-28 weeks often leads to a substantial increase in the prevalence of GDM, without conclusive evidence regarding the benefits on pregnancy outcomes compared to a two-step screening strategy with a glucose challenge test (GCT). In addition, RCTs are needed to investigate the impact of treatment of GDM diagnosed with IADPSG criteria on long-term maternal and childhood outcomes. Selective screening using a risk-factor-based approach could be helpful in simplifying the screening algorithm but carries the risk of missing significant proportions of GDM cases. A two-step screening method with a 50g GCT and subsequently a 75g oral glucose tolerance test (OGTT) with IADPSG could be an alternative to reduce the need for an OGTT. However, to have an acceptable sensitivity to screen for GDM with the IADPSG criteria, the threshold of the GCT should be lowered from 7.8 to 7.2 mmol/L. A pragmatic approach to screen for GDM can be implemented during the COVID-19 pandemic, using fasting plasma glucose (FPG), HbA1c or even random plasma glucose (RPG) to reduce the number of OGTTs needed. However, usual guidelines and care should be resumed as soon as the COVID pandemic is controlled.

A prospective cohort study of postpartum glucose metabolic disorders in early versus standard diagnosed gestational diabetes mellitus

Early gestational diabetes mellitus (eGDM) is diagnosed when fasting plasma glucose before 24 weeks of gestation (WG) is ≥ 5.1 mmol/L, whilst standard GDM is diagnosed between 24 and 28 WG by oral glucose tolerance test (OGTT). eGDM seems to have worse obstetric outcomes than standard GDM. We compared the rates of postpartum glucose metabolism disorders between women with early versus standard GDM in this prospective study on women with GDM from three university hospitals between 2014 and 2016. Patients were included if they were < 24 WG with at least one risk factor for GDM and excluded if they had type 2 diabetes. Patients were assigned to Group 1 (G1) for eGDM according to IADPSG: fasting blood glucose < 24 WG between 5.1 and 7 mmol/L. Group 2 (G2) consisted of patients presenting a standard GDM at 24–28 WG on OGTT results according to IADPSG: T0 ≥ 5.1 mmol/L or T60 ≥ 10.0 mmol g/L or T120 ≥ 8.5 mmol/L. The primary outcome was postpartum OGTT result. Five hundred patients were analysed, with 273 patients undergoing OGTT at 4–18 weeks postpartum: 192 patients in G1 (early) and 81 in G2 (standard). Patients in G1 experienced more insulin therapy during pregnancy than G2 (52.2% versus 32.5%, p < 0.001), but no patients were taking insulin postpartum in either group. G1 patients experienced less preterm labour (2.6% versus 9.1%, p = 0.043), more induced deliveries (38% versus 25%, p = 0.049) and reduced foetal complications (29.2% versus 42.0%, p = 0.048). There was no significant difference in the rate of postpartum glucose metabolism disorders (type 2 diabetes, impaired glucose tolerance, impaired fasting glycaemia) between groups: 48/192 (25%) in G1 and 17/81 (21%) in G2, p = 0.58. Thus the frequency of early postpartum glucose metabolism disorders is high, without difference between eGDM and standard GDM. This supports measurement of fasting plasma glucose before 24 WG and the threshold of 5.1 mmol/L seems appropriate until verification in future studies.

Trial registration: NCT01839448, ClinicalTrials.gov on 22/04/2013.

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

For over 50 years, the diagnosis of gestational diabetes mellitus (GDM) has been based upon an oral glucose tolerance test at 24-28 weeks' gestation. This is the time during pregnancy when insulin resistance is increasing and hyperglycemia develops among those with insufficient insulin secretory capacity to maintain euglycemia. The Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study and the two major randomized controlled trials of treating GDM are based upon recruitment of women at this time during pregnancy. Meanwhile, the increasing prevalence of type 2 diabetes in pregnancy, with its significant risk of adverse pregnancy outcomes, has led to a need to identify undiagnosed diabetes as near to conception as possible. Screening for undiagnosed diabetes early in pregnancy also identifies women with hyperglycemia less than overt diabetes, yet at increased risk of adverse pregnancy outcomes. Such women are more insulin resistant-with higher blood pressure, triglycerides, perinatal mortality, and neonatal hypoglycemia with a greater need for insulin treatment-than those with GDM diagnosed at 24-28 weeks' gestation. Currently, there is uncertainty over how to diagnose GDM early in pregnancy and the benefits and harms from using the current management regimen. Randomized controlled trials testing the criteria for, and treatment of, GDM early in pregnancy are urgently needed to address this existing equipoise. In the meantime, the importance of early or "prevalent GDM" (i.e., mild hyperglycemia present from early [before] pregnancy) warrants interim criteria and thresholds for medication, which may differ from those in use for GDM diagnosed at 24-28 weeks' gestation.

Emerging Protein Biomarkers for the Diagnosis or Prediction of Gestational Diabetes-A Scoping Review

Introduction: Gestational diabetes (GDM), defined as hyperglycemia with onset or initial recognition during pregnancy, has a rising prevalence paralleling the rise in type 2 diabetes (T2DM) and obesity. GDM is associated with short-term and long-term consequences for both mother and child. Therefore, it is crucial we efficiently identify all cases and initiate early treatment, reducing fetal exposure to hyperglycemia and reducing GDM-related adverse pregnancy outcomes. For this reason, GDM screening is recommended as part of routine pregnancy care. The current screening method, the oral glucose tolerance test (OGTT), is a lengthy, cumbersome and inconvenient test with poor reproducibility. Newer biomarkers that do not necessitate a fasting sample are needed for the prompt diagnosis of GDM. The aim of this scoping review is to highlight and describe emerging protein biomarkers that fulfill these requirements for the diagnosis of GDM. Materials and Methods: This scoping review was conducted according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines for scoping reviews using Cochrane Central Register of Controlled Trials (CENTRAL), the Cumulative Index to Nursing & Allied Health Literature (CINAHL), PubMed, Embase and Web of Science with a double screening and extraction process. The search included all articles published in the literature to July 2020. Results: Of the 3519 original database citations identified, 385 were eligible for full-text review. Of these, 332 (86.2%) were included in the scoping review providing a total of 589 biomarkers studied in relation to GDM diagnosis. Given the high number of biomarkers identified, three post hoc criteria were introduced to reduce the items set for discussion: we chose only protein biomarkers with at least five citations in the articles identified by our search and published in the years 2017-2020. When applied, these criteria identified a total of 15 biomarkers, which went forward for review and discussion. Conclusions: This review details protein biomarkers that have been studied to find a suitable test for GDM diagnosis with the potential to replace the OGTT used in current GDM screening protocols. Ongoing research efforts will continue to identify more accurate and practical biomarkers to take GDM screening and diagnosis into the 21st century.

Screening for Gestational Diabetes Mellitus in Early Pregnancy: What Is the Evidence?

The incidence of gestational diabetes mellitus (GDM) is increasing worldwide. This has a significant effect on the health of the mother and offspring. There is no doubt that screening for GDM between 24 and 28 weeks is important to reduce the risk of adverse pregnancy outcomes. However, there is no consensus about diagnosis and treatment of GDM in early pregnancy. In this narrative review on the current evidence on screening for GDM in early pregnancy, we included 37 cohort studies and eight randomized controlled trials (RCTs). Observational studies have shown that a high proportion (15–70%) of women with GDM can be detected early in pregnancy depending on the setting, criteria used and screening strategy. Data from observational studies on the potential benefit of screening and treatment of GDM in early pregnancy show conflicting results. In addition, there is substantial heterogeneity in age and BMI across the different study populations. Smaller RCTs could not show benefit but several large RCTs are ongoing. RCTs are also necessary to determine the appropriate cut-off for HbA1c in pregnancy as there is limited evidence showing that an HbA1c ≥6.5% has a low sensitivity to detect overt diabetes in early pregnancy.

Early gestational diabetes mellitus (GDM) is associated with worse pregnancy outcomes compared with GDM diagnosed at 24-28 weeks gestation despite early treatment

BACKGROUND

Gestational diabetes mellitus (GDM) is associated+ with adverse pregnancy outcomes compared with women with normal glucose tolerance in pregnancy. The WHO recommends screening at 24-28 weeks gestation for GDM. Women who are diagnosed before 24-28 weeks gestation have a longer intervention period which may impact positively on pregnancy outcomes.

AIM

This study aimed to examine pregnancy outcomes of women with GDM diagnosed <24 weeks gestation compared with those diagnosed at 24-28 weeks in a large Irish cohort.

METHODS

A retrospective cohort study of 1471 pregnancies in women with GDM diagnosed using IADPSG criteria between September 2012 and April 2016 was conducted. At GDM diagnosis, women were classified as early GDM <24 weeks or standard GDM 24-28 weeks gestation.

RESULTS

Women with early GDM had a significantly greater risk of pregnancy-induced hypertension (12.4% vs. 5.3%; P < 0.05), post-partum haemorrhage (8.7% vs. 2.4%; P < 0.05) and post-partum glucose abnormalities (32% vs. 15.6%; P < 0.05). Their offspring had a greater risk of pre-maturity (10.9% vs. 6.6%; P < 0.05), stillbirth (1.4% vs. 0.5%; P < 0.05), large for gestational age (19.1% vs. 13.4% P < 0.05) and need neonatal intensive care (30.7% vs. 22.1%; P < 0.05) compared with offspring of women with standard GDM. Rates of C-section and pre-maturity were still higher in the early GDM group when the two groups where compared based on their post-natal OGTT.

CONCLUSION

Early GDM women and their offspring are at greater risk of an adverse pregnancy outcome compared with those diagnosed at 24-28 weeks. In view of the abnormal post-natal glucose findings, early GDM may reflect a more advanced state in diabetes pathogenesis.

Women with Mild Fasting Hyperglycemia in Early Pregnancy Have More Neonatal Intensive Care Admissions

AIMS

To determine impact of mild fasting hyperglycemia in early pregnancy (fasting plasma glucose [FPG] 5.1-5.5 mmol/L) on pregnancy outcomes.

METHODS

We measured FPG at 11.9 ± 1.8 weeks in 2006 women from a prospective cohort study. Women with FPG ≥5.6 mmol/L (19) received treatment and were excluded from further analyses. A total of 1838 women with FPG <5.6 mmol/L received a 75 g oral glucose tolerance test (OGTT) between 24 and 28 weeks of pregnancy.

RESULTS

Of all participants, 78 (4.2%) had FPG 5.1 to 5.5 mmol/L in early pregnancy, of which 49 had a normal OGTT later in pregnancy (high fasting normal glucose tolerance [NGT] group). Compared with the NGT group with FPG <5.1 mmol/L in early pregnancy (low fasting NGT group, n = 1560), the high fasting NGT group had a higher body mass index (BMI), higher insulin resistance with more impaired insulin secretion and higher FPG and 30 minute glucose levels on the OGTT. The admission rate to neonatal intensive care unit (NICU) was significantly higher in the high fasting NGT group than in the low fasting NGT group (20.4% [10] vs 9.3% [143], P = .009), with no difference in duration (7.0 ± 8.6 vs 8.4 ± 14.3 days, P = .849) or indication for NICU admission between both groups. The admission rate to NICU remained significantly higher (odds ratio 2.47; 95% confidence interval 1.18-5.19, P = .017) after adjustment for age, BMI, and glucose levels at the OGTT.

CONCLUSIONS

When provision of an OGTT is limited such as in the Covid-19 pandemic, using FPG in early pregnancy could be an easy alternative to determine who is at increased risk for adverse pregnancy outcomes.

Attenuated early pregnancy weight gain by prenatal lifestyle interventions does not prevent gestational diabetes in the LIFE-Moms consortium

AIMS

To examine the effect of lifestyle (diet and physical activity) interventions on the prevalence of GDM, considering the method of GDM ascertainment and its association with early pregnancy characteristics and maternal and neonatal outcomes in the LIFE-Moms consortium.

METHODS

LIFE-Moms evaluated the effects of lifestyle interventions to optimize gestational weight gain in 1148 pregnant women with BMI ≥ 25 kg/m2 and without known diabetes at enrollment, compared with standard care. GDM was assessed between 24 and 31-weeks gestation by a 2-hour, 75-gram OGTT or by local clinical practice standards.

RESULTS

Lifestyle interventions initiated prior to 16 weeks reduced early excess GWG compared with standard care (0.35 ± 0.24 vs 0.43 ± 0.26 kg per week, p=<0.0001) but did not affect GDM diagnosis (11.1% vs 11.6%, p = 0.91). Using the 75-gram, 2-hour OGTT, 13. 0% of standard care and 11.0% of the intervention group had GDM by the IADPSG criteria (p = 0.45). The 'type of diagnostic test' did not change the result (p = 0.86). Women who developed GDM were significantly heavier, more likely to have obesity, and more likely to have dysglycemia at baseline.

CONCLUSION

Moderate-to-high intensity lifestyle interventions grounded in behavior change theory initiated between 9 and 16-weeks gestation did not affect the prevalence of GDM despite reducing early GWG. CLINICALTRIALS.GOV: NCT01545934, NCT01616147, NCT01771133, NCT01631747, NCT01768793, NCT01610752, NCT01812694.

Early Versus Routine Oral Glucose Tolerance Test in Women With Intermediate Hyperglycemia at First Prenatal Visit: A Retrospective Cohort Study in China

BACKGROUND AND OBJECTIVES

Intermediate hyperglycemia in the first half of pregnancy, defined as a fasting plasma glucose level between 5.1- 6.9 mM, increases the risk of gestational diabetes mellitus, but clinical evidence for further management is lacking. We aim to evaluate the effectiveness of an early oral glucose tolerance test (OGTT) followed by the identification of intermediate hyperglycemia on pregnancy outcomes in real world setting.

SUBJECTS AND METHODS

A retrospective cohort study was conducted at the Obstetrics and Gynecology Hospital, Shanghai, China, between 2013 and 2017. Women with intermediate hyperglycemia at the first prenatal visit were identified and underwent an immediate (within one week) or a routine OGTT (24-28 gw) according to their wishes and received nutrition and exercise advice. Women diagnosed of gestational diabetes (GDM) were managed by standard interventions. Primary outcome was larger for gestational age (LGA). Secondary outcomes were primary cesarean delivery, preterm birth, shoulder dystocia or forceps delivery, preeclampsia, neonatal hypoglycemia, hyperbilirubinemia, and low Apgar score. Logistic regressions with or without a further propensity score-matched analysis were performed.

RESULTS

Among 42406 women involved, 1104 (2.6%) with intermediate hyperglycemia at the first prenatal visit were identified, of whom 176 (15.9%) underwent an early OGTT and 741 (67.1%) received a routine OGTT. Logistic regression showed that an early OGTT was not significantly associated with an altered risk of LGA (adjusted OR 1.13, 95% CI 0.73-1.75) but was related to an increased odds for neonatal hyperbilirubinemia (adjusted OR 2.89; 95% CI 1.55-5.37). No significant associations were observed for other secondary outcomes. These trends remained consistent in propensity score-matched models.

CONCLUSIONS

Our data from a real-world setting did not support that an early OGTT among women with intermediate hyperglycemia at the first prenatal visit improved pregnancy outcomes.

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.

Sonographic and other nonglycemic factors can predict large-for-gestational-age infants in diet-managed gestational diabetes mellitus: A retrospective cohort study

BACKGROUND

Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy. Left untreated or poorly controlled, GDM results in adverse infant outcomes such as large for gestational age (LGA). This study aims to identify nonglycemic maternal and fetal factors predictive of LGA outcomes in pregnancies complicated by diet-managed GDM.

METHODS

This was a retrospective cohort study of singleton pregnancies complicated by diet-managed GDM from 2004 to 2015. Multiple logistic regression analysis was performed on maternal and perinatal factors to identify risk factors for LGA. In addition, a subset univariate analysis was conducted for pregnancies in which fetal ultrasound abdominal circumference measurements were available at gestational weeks 18 to 22, 24 to 28, and 29 to 33.

RESULTS

A total of 1064 women were included, delivering 123 LGA infants. Women with higher parity (odds ratio [OR] 1.44; CI, 1.23-1.68; P < .001) and higher prepregnancy body mass index (BMI) (OR 1.09; CI, 1.06-1.12; P < .001) were more likely to have LGA infants. Maternal smoking (OR 0.30; CI, 0.14-0.62; P = .001) and higher gestational age at birth (OR 0.91; CI, 0.84-0.99; P = .018) were associated with reduced risk. Subset univariate analysis showed that fetal abdominal circumference measurements at weeks 24 to 28 and 29 to 33 beyond the 75th percentile (OR 5.92 and 13.74, respectively) and 90th percentile (OR 4.57 and 15.89, respectively) were highly predictive of LGA.

CONCLUSIONS

Parity, smoking status, maternal BMI, gestational age, and ultrasound fetal abdominal circumference measurements were identified as useful predictors of LGA. Presence of these predictors may prompt closer monitoring of pregnancy and early therapeutic intervention to improve management and reduce the risk of adverse fetal and maternal outcomes.

Factors associated with macrosomia, hypoglycaemia and low Apgar score among Fijian women with gestational diabetes mellitus

Background

Gestational diabetes mellitus (GDM) in Fiji is a serious public health issue. However, there are no recent studies on GDM among pregnant women in Fiji. The aim of this study was to examine prevalence of, and sociodemographic factors associated with adverse neonatal outcomes among Fijian women with GDM.

Methods

We used cross-sectional data of 255 pregnant women with GDM who gave birth to singleton infants at Colonial War Memorial Hospital (CWMH) in Suva city. Women underwent testing for GDM during antenatal clinic visits and were diagnosed using modified International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. Multivariable logistic regression analysis was used to investigate factors associated with neonatal outcomes.

Results

Women with a previous baby weighing > 4 kg were 6.08 times more likely to experience neonatal macrosomia (Adjusted odds ratio (AOR) = 6.08; 95%CI: 2.46, 15.01). Compared to unmarried women, the odds of macrosomia among married women reduced by 71% (AOR = 0.29; 95%CI: 0.11, 0.77). Compared with delivery before 38 weeks of gestation, the infants of women who delivered between 38 and 41 weeks of gestation were 62 and 86% less likely to experience neonatal hypoglycaemia and Apgar score < 7 at 5 mins, respectively. The offspring of women who were overweight and obese had higher odds of neonatal hypoglycaemia. Late booking in gestation (≥28 weeks) was significantly associated with Apgar score < 7 at 5 min (AOR = 7.87; 95%CI: 1.11, 55.75). Maternal pre-eclampsia/pregnancy induced hypertension was another factor associated with low Apgar score in infants.

Conclusions

The study found high rates of adverse neonatal outcomes among off springs of Fijian women with GDM and showed that interventions targeting pregnant women who are overweight, had a previous baby weighing > 4 kg, had pre-eclampsia, delivered before 38 weeks of gestation, and those who booked later than 13 weeks in gestation, are needed to improve pregnancy outcomes.

Early Pregnancy Screening for Women at High-Risk of GDM Results in Reduced Neonatal Morbidity and Similar Maternal Outcomes to Routine Screening

The Australasian Diabetes in Pregnancy Society recommends screening high-risk women for gestational diabetes mellitus (GDM) before 24 weeks gestation, under the assumption that an earlier diagnosis and opportunity to achieve normoglycemia will minimize adverse outcomes. However, little evidence exists for this recommendation. The study objective was to compare the pregnancy outcomes of high-risk women diagnosed with GDM before 24 weeks gestation and routinely diagnosed women after 24 weeks gestation. A retrospective audit was conducted of all pregnancies diagnosed with GDM using International Association of Diabetes and Pregnancy Study Groups criteria over 12 months at a tertiary Australian hospital. Adverse perinatal outcomes were compared between “Early GDM” diagnosed before 24 weeks (n = 133) and “Late GDM” diagnosed from 24 weeks (n = 636). Early GDM had a significantly lower newborn composite outcome frequency (hypoglycemia, birth trauma, NICU/SCN admission, stillbirth, neonatal death, respiratory distress, and phototherapy) compared to Late GDM (20.3% vs. 30.0%, p = 0.02). Primary cesarean, hypertensive disorders, postpartum hemorrhage, birthweight >90th percentile, macrosomia, and preterm birth frequencies were not significantly different between groups. Therefore, high-risk women diagnosed with GDM in early pregnancy were not more likely to have an adverse outcome compared to routinely diagnosed women. As they are a high-risk group, this may indicate a possible benefit to the early diagnosis of GDM.

Appropriate Timing of Gestational Diabetes Mellitus Diagnosis in Medium- and Low-Risk Women: Effectiveness of the Italian NHS Recommendations in Preventing Fetal Macrosomia

BACKGROUND

Screening strategies for gestational diabetes mellitus (GDM) earlier than 24-28 weeks of gestation should be considered to prevent adverse pregnancy outcomes. Nonetheless, there is uncertainty about which women would benefit most from early screening and which screening strategies should be offered to women with GDM. The Italian National Healthcare Service (NHS) recommendations on selective screening for GDM at 16-18 weeks of gestation are effective in preventing fetal macrosomia in high-risk (HR) women, but the appropriateness of timing and effectiveness of these recommendations in medium- (MR) and low-risk (LR) women are still controversial. Patients and Methods. We retrospectively enrolled 769 consecutive singleton pregnant women who underwent both anomaly scan at 19-21 weeks of gestation and screening for GDM at 16-18 and/or 24-28 weeks of gestation, in agreement with the NHS recommendations and risk stratification criteria. Comparison of maternal characteristics, fetal biometric parameters at anomaly scan (head circumference (HC), biparietal diameter (BPD), abdominal circumference (AC), femur length (FL), estimated fetal weight (EFW)), and neonatal birth weight (BW) percentile among risk groups was examined.

RESULTS

219 (28.5%) women were diagnosed with GDM, while 550 (71.5%) were normal glucose-tolerant women. Out of 164 HR women, only 62 (37.8%) underwent the recommended early screening for GDM at 16-18 weeks of gestation. AC and EFW percentiles, as well as neonates' BW percentiles, were significantly higher in HR women diagnosed with GDM at 24-28 weeks of gestation with respect to normal glucose-tolerant women, as well as MR and LR women who tested positive for GDM. Comparative analysis between MR and LR women with GDM and women with normal glucose tolerance revealed significant differences in both AC and EFW percentiles (P < 0.05), while there was no significant difference in neonatal BW percentiles.

CONCLUSION

In MR and LR women with GDM, a mild acceleration of fetal growth can be detected at the time of anomaly scan. However, in these at-risk categories, the NHS recommendations for screening and treatment of GDM at 24-28 weeks of gestation are still effective in normalizing BW and preventing fetal macrosomia, thus supporting a risk factor-based selective screening program for GDM.

The Effects of Lifestyle and/or Vitamin D Supplementation Interventions on Pregnancy Outcomes: What Have We Learned from the DALI Studies?

PURPOSE OF REVIEW

The DALI (vitamin D and lifestyle intervention in the prevention of gestational diabetes mellitus (GDM)) study aimed to prevent GDM with lifestyle interventions or Vitamin D supplementation (1600 IU/day). This review summarizes the learnings from the DALI studies among pregnant women with a BMI ≥ 29 kg/m².

RECENT FINDINGS

Women diagnosed with GDM earlier in pregnancy had a worse metabolic profile than those diagnosed later. A combined physical activity (PA) and healthy eating (HE) lifestyle intervention improved both behaviours, limited gestational weight gain (GWG) and was cost-effective. Although GDM risk was unchanged, neonatal adiposity was reduced due to less sedentary time. Neither PA nor HE alone limited GWG or GDM risk. Fasting glucose was higher with HE only intervention, and lower with Vitamin D supplementation. Our combined intervention did not prevent GDM, but was cost-effective, limited GWG and reduced neonatal adiposity.

Reduced size at birth and persisting reductions in adiposity in recent, compared with earlier, cohorts of infants born to mothers with gestational diabetes mellitus

AIMS/HYPOTHESIS

This study aimed to explore the infancy growth trajectories of 'recent' and 'earlier' offspring of mothers with gestational diabetes mellitus (OGDM), each compared with the same control infants, and investigate whether 'recent' OGDM still exhibit a classical phenotype, with macrosomia and increased adiposity.

METHODS

Within a prospective observational birth cohort, 98 'earlier' OGDM born between 2001 and 2009 were identified using 75 g oral glucose tolerance testing at 28 weeks gestation, 122 recent OGDM born between 2011 and 2013 were recruited postnatally through antenatal diabetes clinics, and 876 normal birthweight infants of mothers with no history of diabetes were recruited across the full study period as the control group. All infants followed the same study protocol (measurements at birth, 3, 12 and 24 months, including weight, length and skinfold thickness indicating adiposity, and detailed demographic data). In all cases, GDM was defined using the International Association of Diabetes and Pregnancy Study Group criteria.

RESULTS

Earlier OGDM had higher birthweight SD scores (SDS) than control infants. Conversely, recent OGDM had similar birthweight- and length SDS to control infants (mean ± SD, 0.1 ± 1.0 and- 0.1 ± 0.9, respectively), but lower mean skinfold thickness SDS (-0.4 ± 0.6 vs 0.0 ± 0.9; p < 0.001). After birth, earlier OGDM showed reduced gains in weight and length between 3 and 12 months. In contrast, recent OGDM had increased weight and skinfold thickness gains until 3 months, followed by reduced gains in those variables from 3 to 12 months, compared with control infants. At 24 months, recent OGDM had lower adiposity than control infants (mean skinfold thickness SDS -0.3 ± 0.7 vs 0.0 ± 0.8; p < 0.001). At all time points recent OGDM had lower growth measurements than earlier OGDM.

CONCLUSIONS/INTERPRETATION

Recent OGDM showed different growth trajectories to the earlier group, namely normalisation of birthweight and reduced adiposity at birth, followed by initial rapid weight gain but subsequent reduced adiposity postnatally. While avoidance of macrosomia at birth may be advantageous, the longer-term health implications of these changing growth trajectories are uncertain.

Associations of dietetic management with maternal and neonatal health outcomes in women diagnosed with gestational diabetes: a retrospective cohort study

BACKGROUND

In 2010, the recommended diagnostic thresholds for gestational diabetes mellitus (GDM) were amended, which has increased GDM diagnoses, as well as pressure on the services involved in GDM management, specifically impacting dietetic workloads. The present study examined the associations between dietetic intervention in women with GDM and maternal and neonatal health outcomes.

METHODS

The present study involved 1233 adult women with GDM who delivered at The Royal Women's Hospital (RWH), Melbourne, Australia, between July 2015 and May 2017. Retrospective data assessing GDM-care (therapy type, diagnosis time and model of care, maternal and neonatal health outcomes, and outpatient dietetic consultations) were retrieved from patient medical records. Unadjusted and adjusted linear and logistic regression were used to assess associations of GDM care dietetic intervention and GDM care and dietetic intervention with maternal and neonatal health outcomes.

RESULTS

Women receiving dietetic intervention had a decreased likelihood of infant admission to the neonatal intensive care unit or special care nursery than women who not receiving dietetic intervention [adjusted odds ratio (OR) = 0.41, 95% confidence interval (CI) = 0.22-0.75; P = 0.004). Women requiring pharmacotherapy were more likely to experience maternal complications (adjusted OR = 3.13, 95% CI = 2.23-4.41; P < 0.001) and had a greater number of dietetic consultations (β-coefficient = 0.28, 95% CI = 0.17-0.39; P < 0.001) compared to women managed through diet.

CONCLUSIONS

Dietetic intervention plays a key role in optimising maternal and neonatal health outcomes for women with GDM. Exploring further the impact of dietetic intervention in women diagnosed with GDM is key with respect to understanding the optimal delivery of care for these women. The type and number of consultations included in a dietetic intervention should be investigated further.

Early screening and treatment of gestational diabetes in high-risk women improves maternal and neonatal outcomes: A retrospective clinical audit

AIMS

Evidence suggests that screening for gestational diabetes (GDM) occurs too late in pregnancy, when changes in glucose metabolism and fetal growth rates can already be detected. In August 2016 NHS Lothian began screening women with risk factors for GDM during early pregnancy (11-13 weeks). We hypothesised that an earlier identification and treatment of dysglycaemia would improve pregnancy outcomes compared to previous standard care.

METHODS

We compared management and outcomes for singleton pregnancies with GDM delivering at Royal Infirmary Edinburgh, UK, diagnosed through routine or early screening from 01/01/2015-31/10/2017 (routine screening n = 335, early screening n = 241).

RESULTS

Early screening increased the proportion of women diagnosed before 24 weeks' gestation (n = 59/335, 17.6% vs n = 103/241, 42.7%, p < 0.001) but did not change the average monthly rate of diagnosis. Early screening increased the median duration of GDM during pregnancy (71 vs 93 days of gestation, p < 0.001) with no significant changes in the pharmacological management. Early screening improved the primary composite outcome (emergency caesarean section, neonatal hypoglycaemia and macrosomia; n = 138/335, 41.2% vs n = 73/241, 30.3%, adjusted Odds Ratio [95% confidence interval] 0.62 [0.43-0.91].

CONCLUSIONS

There is a role for early screening and management of GDM however it is unclear whether this represents a cost-effective intervention.

Oral anti-diabetic agents for women with established diabetes/impaired glucose tolerance or previous gestational diabetes planning pregnancy, or pregnant women with pre-existing diabetes

BACKGROUND

While most guidance recommends the use of insulin in women whose pregnancies are affected by pre-existing diabetes, oral anti-diabetic agents may be more acceptable to women. The effects of these oral anti-diabetic agents on maternal and infant health outcomes need to be established in pregnant women with pre-existing diabetes or impaired glucose tolerance, as well as in women with previous gestational diabetes mellitus preconceptionally or during a subsequent pregnancy. This review is an update of a review that was first published in 2010.

OBJECTIVES

To investigate the effects of oral anti-diabetic agents in women with established diabetes, impaired glucose tolerance or previous gestational diabetes who are planning a pregnancy, or pregnant women with pre-existing diabetes, on maternal and infant health. The use of oral anti-diabetic agents for the management of gestational diabetes in a current pregnancy is evaluated in a separate Cochrane Review.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 October 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs assessing the effects of oral anti-diabetic agents in women with established diabetes, impaired glucose tolerance or previous gestational diabetes who were planning a pregnancy, or pregnant women with pre-existing diabetes. Cluster-RCTs were eligible for inclusion, but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of the included RCTs. Review authors checked the data for accuracy, and assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

We identified six RCTs (707 women), eligible for inclusion in this updated review, however, three RCTs had mixed populations (that is, they included pregnant women with gestational diabetes) and did not report data separately for the relevant subset of women for this review. Therefore we have only included outcome data from three RCTs; data were available for 241 women and their infants. The three RCTs all compared an oral anti-diabetic agent (metformin) with insulin. The women in the RCTs that contributed data had type 2 diabetes diagnosed before or during their pregnancy. Overall, the RCTs were judged to be at varying risk of bias. We assessed the quality of the evidence for selected important outcomes using GRADE; the evidence was low- or very low-quality, due to downgrading because of design limitations (risk of bias) and imprecise effect estimates (for many outcomes only one or two RCTs contributed data).For our primary outcomes there was no clear difference between metformin and insulin groups for pre-eclampsia (risk ratio (RR) 0.63, 95% confidence interval (CI) 0.33 to 1.20; RCTs = 2; participants = 227; very low-quality evidence) although in one RCT women receiving metformin were less likely to have pregnancy-induced hypertension (RR 0.58, 95% CI 0.37 to 0.91; RCTs = 1; participants = 206; low-quality evidence). Women receiving metformin were less likely to have a caesarean section compared with those receiving insulin (RR 0.73, 95% CI 0.61 to 0.88; RCTs = 3; participants = 241; low-quality evidence). In one RCT there was no clear difference between groups for large-for-gestational-age infants (RR 1.12, 95% CI 0.73 to 1.72; RCTs = 1; participants = 206; very low-quality evidence). There were no perinatal deaths in two RCTs (very low-quality evidence). Neonatal mortality or morbidity composite outcome and childhood/adulthood neurosensory disability were not reported.For other secondary outcomes we assessed using GRADE, there were no clear differences between metformin and insulin groups for induction of labour (RR 1.42, 95% CI 0.62 to 3.28; RCTs = 2; participants = 35; very low-quality evidence), though infant hypoglycaemia was reduced in the metformin group (RR 0.34, 95% CI 0.18 to 0.62; RCTs = 3; infants = 241; very low-quality evidence). Perineal trauma, maternal postnatal depression and postnatal weight retention, and childhood/adulthood adiposity and diabetes were not reported.

AUTHORS' CONCLUSIONS

There are insufficient RCT data to evaluate the use of oral anti-diabetic agents in women with established diabetes, impaired glucose tolerance or previous gestational diabetes who are planning a pregnancy, or in pregnant women with pre-existing diabetes. Low to very low-quality evidence suggests possible reductions in pregnancy-induced hypertension, caesarean section birth and neonatal hypoglycaemia with metformin compared with insulin for women with type 2 diabetes diagnosed before or during their pregnancy, and no clear differences in pre-eclampsia, induction of labour and babies that are large-for-gestational age. Further high-quality RCTs that compare any combination of oral anti-diabetic agent, insulin and dietary and lifestyle advice for these women are needed. Future RCTs could be powered to evaluate effects on short- and long-term clinical outcomes; such RCTs could attempt to collect and report on the standard outcomes suggested in this review. We have identified three ongoing studies and four are awaiting classification. We will consider these when this review is updated.