Testing For Gestational Diabetes Mellitus Research Articles

Fetal abdominal obesity in women with one value abnormality on diagnostic test for gestational diabetes mellitus.

Previous studies have shown that fetal abdominal obesity (FAO) was already observed at the time of gestational diabetes mellitus (GDM) diagnosis and persisted until delivery despite management in older and/or obese women. In this study, we investigated whether fetuses of women with milder hyperglycemia than GDM have accelerated abdominal growth, leading to adverse pregnancy outcomes. We retrospectively reviewed the medical records of 7,569 singleton pregnant women who were universally screened using a 50-g glucose challenge test (GCT) and underwent a 3-h 100-g oral glucose tolerance test (OGTT) if GCT result was ≥140mg/dL. GDM, one value abnormality (OVA), and normal glucose tolerance (NGT, NGT1: GCT negative, NGT2: GCT positive & OGTT negative) were diagnosed using Carpenter-Coustan criteria. With fetal biometry data measured simultaneously with 50-g GCT, relative fetal abdominal overgrowth was investigated by assessing the fetal abdominal overgrowth ratios (FAORs) of the ultrasonographically estimated gestational age (GA) of abdominal circumference(AC) per actual GA by the last menstruation period(LMP), biparietal diameter(BPD) or femur length(FL), respectively. FAO was defined as FAOR ≥90th percentile The FAORs of GA-AC/GA-LMP and GA-AC/GA-BPD were significantly higher in OVA subjects compared to NGT subjects but not in NGT2 subjects. Although the frequency of FAO in OVA (12.1%) was between that of NGT (9.6%) and GDM (18.3%) without statistically significant difference, the prevalence of large for gestational age at birth and primary cesarean delivery rates were significantly higher in OVA (9.8% and 29.7%) than in NGT (5.1% and 21.5%, p<0.05). Particularly, among OVA subjects with FAO, the prevalence (33.3% and 66.7%) was significantly higher than in those without FAO (9.7% and 24.2%, p<0.05). The degree of fetal abdominal growth acceleration in OVA subjects was intermediate between that of NGT and GDM subjects. OVA subjects with FAO at the time of GDM diagnosis were strongly associated with adverse pregnancy outcomes.

Test characteristics of glycated albumin in the diagnosis of gestational diabetes mellitus

This study determined the test characteristics of glycated albumin in the diagnosis of gestational diabetes mellitus. The gold standard for diagnosing gestational diabetes mellitus is the oral glucose tolerance test which requires patient preparation, drinking of glucose solution, and multiple sample collections. A possible alternative biomarker for the diagnosis of gestational diabetes is glycated albumin does not require patient preparation and only one sample is collected. Glycated albumin levels are higher among Black Americans than in Caucasians.The study involved 200 pregnant women attending the antenatal clinic at the University of Port Harcourt Teaching Hospital. The diagnosis of gestational diabetes mellitus was made using the World Health Organization 2013 diagnostic criteria. The test characteristics of glycated albumin were determined using the area under the curve of the receiver operator characteristic curve, sensitivity, specificity, positive predictive value, and negative predictive value. The prevalence of gestational diabetes mellitus was 9.0%. The area under the receiver operator characteristic curve for glycated albumin was 0.8 (95% CI 0.7-0.9; p=0.0001). The sensitivity and specificity of glycated albumin were 83.3% and 86.8% respectively. The positive predictive value was 38.5% and the negative predictive value was 98.1%. Glycated albumin has high sensitivity, specificity, and negative predictive values and therefore, can be used as a preliminary test for gestational diabetes mellitus.

Prevalence of gestational diabetes mellitus and associated factors among women receiving antenatal care at a tertiary hospital in South-Western Uganda.

gestational diabetes mellitus is one of the major causes of morbidity and mortality among pregnant women worldwide. We aimed to determine the prevalence and factors associated with gestational diabetes mellitus among women attending the antenatal care clinic at a tertiary care hospital in South-Western Uganda. this was a hospital-based cross-sectional study conducted among women at ≥24 weeks of amenorrhea attending the antenatal care clinic at Mbarara Regional Referral Hospital between December 2020 and March 2021. We screened all women for gestational diabetes mellitus using the World Health Organization 2013 diagnostic criteria. We obtained socio-demographic, medical, and obstetric data. Multivariable logistic regression was used to determine the factors independently associated with gestational diabetes mellitus. we enrolled 343 pregnant women with a mean age of 27.3 (SD ±12.3) years. Of the 343 participants, 35 (10.2%) had gestational diabetes mellitus (GDM) (95% C.I: 7.4%-13.9%) and 7 (2%) had diabetes in pregnancy. The factors significantly associated with gestational diabetes mellitus were; previous history of foetal macrosomia in any of the previous pregnancies (aOR: 5.53, 95% C.I: 1.29-23.65) and family history of diabetes mellitus in the first-degree relatives (aOR: 4.45, 95% C.I:1.48-13.34). one in every ten pregnant women attending the antenatal care clinic at Mbarara Regional Referral Hospital is likely to have gestational diabetes mellitus in pregnancy. There is a need to strengthen routine testing for gestational diabetes mellitus among women attending the antenatal care clinic, especially pregnant women with a prior history of foetal macrosomia and a family history of diabetes mellitus in first-degree relatives.

Glucose Testing in an Index Pregnancy and Outcomes in a Subsequent Pregnancy: Implications for Screening and a Novel Risk Calculator.

Our objective was to assess whether variables from an index pregnancy (PG1) can be used to guide testing for gestational diabetes mellitus (GDM) in a subsequent pregnancy (PG2) and to create a risk calculator for GDM in PG2. This was a retrospective cohort study of patients delivering ≥2 singleton gestations at >24 weeks' gestation from June 2009 to December 2018, for whom results of a 1-hour glucose challenge test (GCT) were available from PG1. Univariable and multivariable analyses were performed to evaluate factors associated with GDM in PG2. In total, 4,278 patients met the inclusion criteria. Among patients with a normal 1-hour GCT (<140 mg/dL) in PG1 (n = 3,719), 3.9% were diagnosed with GDM in PG2. In multivariable analysis of this group, GDM in PG2 was associated with higher GCT in PG1 (adjusted odds ratio [aOR]: 1.05, 95% confidence interval [CI]: 1.04-1.06), large for gestational age neonate in PG1 (aOR: 1.97, 95% CI: 1.24-3.13), and higher BMI (aOR: 1.08, 95% CI: 1.05-1.11). A novel risk calculator for GDM in PG2 was developed based on these associations. Using a risk cut-off of 15%, the calculator had a positive predictive value of 26% and a negative predictive value of 97%, with 3.2% of patients identified as "at risk". Among patients with abnormal 1-hour GCT in PG1, 38.3% (n = 214/559) had an abnormal 1-hour GCT in PG2 and 34.5% (n = 74/214) of these patients received a diagnosis of GDM. A normal 1-hour GCT in an PG1 is followed by GDM in a subsequent pregnancy in only 3.9% of cases. A novel calculator supports replacing universal screening with targeted testing in subsequent pregnancies in this population. Among patients with an abnormal 1-hour GCT in PG1, nearly 40% have an abnormal 1-hour GCT in a subsequent pregnancy. Direct diagnostic testing can be considered in such patients. · Normal GCT in a first pregnancy is associated with normal GCT in subsequent pregnancy.. · A risk calculator can target diabetes testing in a subsequent pregnancy.. · Abnormal GCT in a first pregnancy is associated with abnormal GCT in subsequent pregnancy..

One-Step Compared With Two-Step Gestational Diabetes Screening and Pregnancy Outcomes: A Systematic Review and Meta-analysis.

To estimate short-term maternal and neonatal outcomes with one-compared with two-step testing for gestational diabetes mellitus (GDM). A systematic review of randomized controlled trials (RCTs) and observational studies comparing one-step and two-step GDM testing strategies before September 2021 was conducted. We searched Ovid Medline (1946-), EMBASE (1947-), Scopus (1960-), Cochrane Central, and ClinicalTrials.gov . The primary outcome was rate of large-for-gestational age (LGA) neonates. Secondary outcomes were clinically relevant outcomes for GDM that were selected a priori. Titles, abstracts, and manuscripts were screened, selected, and reviewed by the first two authors. Four RCTs (24,966 patients) and 13 observational studies (710,677 patients) were analyzed. Pooled relative risks (RRs) were calculated with 95% CIs using random-effects models and were plotted graphically with forest plots. Study heterogeneity was evaluated using Cochran Q and Higgins I 2 tests. The quality of studies that met the inclusion criteria was evaluated with the Downs and Black checklist. Publication bias was assessed by using asymmetry of funnel plots and Harbord's test. There was no difference in the rate of LGA neonates (pooled RR 0.95; 95% CI 0.88-1.04) by testing strategy among RCTs, but patients who underwent one-step testing were more likely to be diagnosed with GDM (pooled RR 2.13; 95% CI 1.61-2.82) and treated with diabetes medications (pooled RR 2.24; 95% CI 1.21-4.15). One-step testing was associated with higher rates of neonatal intensive care unit (NICU) admission (pooled RR 1.12; 95% CI 1.00-1.26) and neonatal hypoglycemia (pooled RR 1.23; 95% CI 1.13-1.34). In analysis of high-quality RCTs and observational studies, one-step testing was associated with a lower rate of LGA neonates (pooled RR 0.97; 95% CI 0.95-0.98), but higher rates of GDM diagnosis, treatment, NICU admission, and neonatal hypoglycemia. Despite a significant increase in GDM diagnosis and treatment with one-step testing, there is no difference in rate of LGA neonates compared with two-step testing among RCTs. PROSPERO, CRD42021252703.

Cut-off points of 75-gram oral glucose tolerance test as a diagnostic test for gestational diabetes mellitus in pregnant Filipino population

Background: Cut-off points determine the threshold of health status in a patient. For instance, in pregnancy, cut off points of oral glucose tolerance test (OGTT) distinguishes gestational diabetes mellitus (GDM) pregnancy from healthy condition. Currently, OGTT cut-off points used in the Philippines was standardized using a different reference population, which may impact disease diagnosis. This study aims to establish the cut-off points of 75-grams (g) OGTT for the diagnosis of GDM among Filipino pregnant women.

Metabolomic Identification of a Novel, Externally Validated Predictive Test for Gestational Diabetes Mellitus.

ContextUndiagnosed gestational diabetes mellitus (GDM) is a major preventable cause of stillbirth. In the United Kingdom, women are selected for diagnostic testing for GDM based on risk factors, including body mass index (BMI) > 30 kg/m2.ObjectiveTo improve the prediction of GDM using metabolomics.MethodsWe performed metabolomics on maternal serum from the Pregnancy Outcome Prediction (POP) study at 12 and 20 weeks of gestational age (wkGA; 185 GDM cases and 314 noncases). Predictive metabolites were internally validated using the 28 wkGA POP study serum sample and externally validated using 24- to 28-wkGA fasting plasma from the Born in Bradford (BiB) cohort (349 GDM cases and 2347 noncases). The predictive ability of a model including the metabolites was compared with BMI > 30 kg/m2 in the POP study.ResultsForty-seven predictive metabolites were identified using the 12- and 20-wkGA samples. At 28 wkGA, 4 of these [mannose, 4-hydroxyglutamate, 1,5-anhydroglucitol, and lactosyl-N-palmitoyl-sphingosine (d18:1/16:0)] independently increased the bootstrapped area under the receiver operating characteristic curve (AUC) by >0.01. All 4 were externally validated in the BiB samples (P = 2.6 × 10−12, 2.2 × 10−13, 6.9 × 10−28, and 2.6 × 10−17, respectively). In the POP study, BMI > 30 kg/m2 had a sensitivity of 28.7% (95% CI 22.3-36.0%) and a specificity of 85.4% whereas at the same level of specificity, a predictive model using age, BMI, and the 4 metabolites had a sensitivity of 60.2% (95% CI 52.6-67.4%) and an AUC of 0.82 (95% CI 0.78-0.86).ConclusionsWe identified 4 strongly and independently predictive metabolites for GDM that could have clinical utility in screening for GDM.

The diagnostic value of glycosylated hemoglobin for gestational diabetes mellitus in Asian populations: A systematic review and meta-analysis.

To investigate the role of glycosylated hemoglobin in assisting the oral glucose tolerance test for gestational diabetes mellitus (GDM) diagnosis in Asian populations. PubMed, Embase, Web of Science, and the Cochrane Library were searched from inception to December 2020. Review Manager was applied to assess the quality of studies and risk of bias. MetaDiSc was used to measure diagnostic odds ratio, sensitivity, specificity, positive and negative likelihood ratios, area under receiving operating characteristic curve, and heterogeneity. A total of 19 original studies (32 669 women) were retrieved. The diagnostic efficiency of glycosylated hemoglobin was quantified from 4.5% to 6.0%. The pooled sensitivity (0.624, 0.609-0.638) and specificity and (0.624, 0.617-0.631) achieved optimal equilibrium at 5.0%. High sensitivity (0.911, 0.902-0.920) and low negative likelihood ratio (0.431, 0.365-0.508) at 4.6% as the rule-out cut-off, while with limited sensitivity, high specificity (0.990, 0.986-0.993) and positive likelihood ratio (8.309, 4.251-16.242) occurred at 5.8% as the rule-in cut-off. Heterogeneity was detected in parts of subgroup analyses (I2 > 50%). The diagnostic odds ratio and 95% confidence interval performance were better in the population with risk factors (6.314, 3.543-11.254) than those without (4.178, 2.332-7.488). Glycosylated hemoglobin is a potential tool in assisting GDM diagnosis in Asian populations, which has a better applicability based on the rule-out and rule-in algorithm (4.6%-5.8%), particularly for pregnant women with risk factors.

DEVELOPING twin-specific 75-g oral glucose tolerance test diagnostic thresholds for gestational diabetes based on the risk of future maternal diabetes: a population-based cohort study.

To develop twin-specific outcome-based oral glucose tolerance test (OGTT) diagnostic thresholds for GDM based on the risk of future maternal type-2 diabetes. A population-based retrospective cohort study (2007-2017). Ontario, Canada. Nulliparous women with a live singleton (n=55361) or twin (n=1308) birth who underwent testing for gestational diabetes mellitus (GDM) using a 75-g OGTT in Ontario, Canada (2007-2017). We identified the 75-g OGTT thresholds in twin pregnancies that were associated with similar incidence rates of future type-2 diabetes to those associated with the standard OGTT thresholds in singleton pregnancies. For any given 75-g OGTT value, the incidence rate of future maternal type-2 diabetes was lower for women with a twin than women with a singleton pregnancy. Using women with a negative OGTT as reference, the risk of future maternal type-2 diabetes in twin pregnancies with a positive OGTT based on the standard OGTT thresholds (9.86 per 1000 person years, adjusted hazard ratio (aHR) 4.79, 95% CI 2.69-8.51) was lower than for singleton pregnancies with a positive OGTT (18.74 per 1000 person years, aHR 8.22, 95% CI 7.38-9.16). The twin-specific OGTT fasting, 1-hour and 2-hour thresholds identified in the current study based on correlation with future maternal type-2 diabetes were 5.8mmol/l (104mg/dl), 11.8mmol/l (213mg/dl) and 10.4mmol/l (187mg/dl), respectively. We identified potential twin-specific OGTT thresholds for GDM that are associated with a similar risk of future type-2 diabetes to that observed in women diagnosed with GDM in singleton pregnancies based on standard OGTT thresholds. Potential twin-specific OGTT thresholds for GDM were identified.

Glycated Haemoglobin: Is it a Better Reference Method than Oral Glucose Tolerance Test for the Diagnosis of Gestational Diabetes Mellitus?

Introduction: Insulin resistance during pregnancy is associated with adverse effects on foetal and maternal health, including macrosomia, congenital malformations, perinatal mortality and pre-eclampsia. A 100 g Oral Glucose Tolerance Test (OGTT) is recommended by World Health Organisation (WHO) as the diagnostic test for Gestational Diabetes Mellitus (GDM). However, the inconvenience caused to the pregnant females due to time consuming and cumbersome multi-invasive procedure for performing OGTT has prompted the exploration of an alternative method. Aim: To ascertain whether Glycated Haemoglobin (HbA1c) can be used instead of OGTT for diagnosis of GDM. Materials and Methods: It was a case-control study which was conducted for one year from June 2012 to May 2013. In this study, 200 pregnant females with gestational age from 22-40 weeks underwent Fasting Blood Sugar (FBS), Glucose Challenge Test (GCT) with 50 g glucose load, OGTT and HbA1c investigations. Results: The mean HbA1c of Group 1 with GDM was 5.29±0.68% and mean HbA1c of Group 2 without GDM was 4.83±0.46%. At the HbA1c cut-off of ≥5.85%, 18% of GDM patients were identified with specificity of 97%. A higher HbA1c cut-off of ≥5.95% showed sensitivity and specificity of 16.3% and 70%, respectively. An arbitrary cut-off of ≥5.85% would have diagnosed only 18% of patients with GDM with reasonable specificity. According to this study, 88% of GDM cases stayed undiagnosed by HbA1c at a cut-off of ≥5.85%. Hence, it can play only a supplemental role to OGTT in diagnosing GDM. Conclusion: On the basis of the present study, HbA1c can be used as a supplemental investigation in addition to OGTT for confirmation of GDM in pregnant females. Only drawback was the lack of fixed HbA1c cut-off for diagnosing GDM.

Diagnostic accuracy of fasting plasma glucose as a screening test for gestational diabetes mellitus: a systematic review and meta-analysis.

Fasting plasma glucose (FPG) is suggested as a potential screening test for further confirmatory testing by oral glucose tolerance test (OGTT) for diagnosing gestational diabetes mellitus (GDM). The diagnostic accuracy of FPG has been investigated in several studies with varying results. This meta-analysis is done to evaluate the diagnostic accuracy of FPG for the screening of GDM. We conducted a systematic search for all studies reporting the diagnostic accuracy of FPG with OGTT as the reference standard in the databases of Medline, Scopus, Cochrane and Embase from inception till January 2020. Quality assessment of diagnostic accuracy studies-2 tool was used to assess the quality of trials. 29 studies with 74,481 patients were included. Eleven studies used the cut-off values of 92mg/dl for FPG to diagnose GDM, whereas 10 studies used the value of 92 mg/dl. The pooled sensitivity and specificity of FPG for cut-off ≥92 mg/dl was 68.6% (95% CI: 51.8%-81.9%), and 93.2% (95% CI: 80.5%-97.8%) respectively. The AUC was 0.88 (95% CI: 0.79-0.94). The pooled sensitivity and specificity of FPG for cut-off ≥90 mg/dl was 58.5% (95% CI: 41.1%-73.9%), and 89.2% (95% CI: 78.5%-94.9%) respectively. The AUC was 0.83 (95% CI: 0.75-0.91). The overall quality of studies was moderate. To summarize, our study found that FPG may have a role in the screening of GDM among pregnant women with satisfactory sensitivity and specificity at a cut-off of 92 mg/dl. Further studies exploring its accuracy in different ethnic populations in reference to a standard OGTT are required to strengthen the evidence.

Gestational diabetes mellitus testing in the COVID-19 pandemic: The problems with simplifying the diagnostic process.

BackgroundMultiple professional bodies have temporarily revised recommendations for gestational diabetes mellitus (GDM) testing during the COVID‐19 pandemic to reduce person‐to‐person contact. The current Australian temporary criteria advise that if the fasting glucose is ≤4.6 mmol/L, then no glucose tolerance test (GTT) is required.AimsThe aim of this study is to examine the extent of underdiagnosis of GDM using a fasting glucose ≤4.6 mmol/L as a cut‐off to determine that a GTT is not necessary.Materials and MethodsDe‐identified data from pregnant women having a GTT test in the Illawarra area during a six‐year period was used to determine the number of women with GDM and the proportion of positive cases that would be missed for different fasting glucose values.ResultsThere were 16 522 results identified and GDM was diagnosed in 12.2%. The majority of women were more than 30 years of age (85.2%) and diagnosed at ≥20 weeks gestation (81.1%). Of those diagnosed with GDM, 29% had a fasting glucose of ≤4.6 mmol/L and would have been missed.ConclusionsOur results show that using a fasting glucose of 4.6 mmol/L or less would miss nearly a third of women who would otherwise be diagnosed with GDM.

One step oral glucose challenge test as screening and diagnostic test for Gestational Diabetes Mellitus

Aim: The Diabetes in Pregnancy Study Group of India (DIPSI, 2010) guidelines recommend the non-fasting 75-g oral glucose challenge test (OGCT) as a single-step screening and diagnostic test for gestational diabetes mellitus (GDM). The aim of this study was to assess the validity of DIPSI criteria by comparing with the World Health Organization (WHO) 1999 criteria of diagnosing GDM.&#x0D; Methods: This study was a hospital based prospective comparative study conducted among 282 pregnant women, of gestational age of 24-28 weeks attending antenatal OPD of Patan hospital. The OGCT was performed on them irrespective of fasting state and without any dietary preparation and they were again asked to come after 3 days of unrestricted carbohydrate diet in fasting state for WHO 2-hour oral glucose tolerance test (OGTT) with 75 gram of glucose load. The value of OGCT &gt;140 mg/dl is diagnostic of GDM (DIPSI 2010). For the reliability of this test, it was compared with WHO 2-hour OGTT.&#x0D; Results: Among the study population, the mean age and BMI was 26.04±4.50 and 24.08±3.30 respectively. Out of 282 patients, 8 cases (2.83%) were found to have abnormal non-fasting 75-g OGCT and 4 cases (1.41%) had abnormal WHO 2-hour OGTT. Paired t test was employed to examine the difference of blood glucose level of the tests. There was statistically significant difference (p&lt;0.001) between the tests. The Sensitivity, specificity, positive predictive value and negative predictive value of oral glucose challenge test was 25%, 97.48%, 12.5% and 98.90% respectively. The non- fasting 75-g OGCT was able to detect only 25% of the cases.&#x0D; Conclusions: Though the non-fasting 75-g OGCT test is cost effective and more compliant to pregnant women, the present report suggests that it cannot be used as a single step screening and diagnostic test because of its low sensitivity. However, it is an adequate alternative for screening test in resources limited areas.

Maternal serum glycosylated hemoglobin and fasting plasma glucose predicts gestational diabetes at the first trimester in Turkish women with a low-risk pregnancy and its relationship with fetal birth weight; a retrospective cohort study

Objective To examine the accuracy of maternal serum glycosylated hemoglobin (HbA1c) and fasting plasma glucose (FPG) levels in predicting gestational diabetes at the first trimester in Turkish women with a low-risk pregnancy and its relationship with fetal birth weight. Methods This cohort study was conducted retrospectively in a tertiary referral hospital from January 2010 to January 2017. HbA1c and FPG serum concentrations were measured in 670 pregnant women at the first-trimester screening. HbA1c and FPG concentrations of women who subsequently developed gestational diabetes mellitus (GDM) were compared to those who did not, and its relationship with fetal weight was investigated. Results First-trimester screening was performed on 608 pregnant women, of whom 69 (11.3%) women had developed GDM. Median HbA1c and FPG concentrations were significantly higher in women developing GDM (n = 69) in comparison to those with uncomplicated pregnancies (n = 539) (5.31 ± 0.58% versus 5.01 ± 0.45%, p < .001 and 89.74 ± 8.71% versus 84.09 ± 9.16%, p < .001, respectively). The cut-off value calculated with the highest Youden index was HbA1c levels above 5.6% with a sensitivity of 34.78%, specificity of 89.8%, with a diagnostic accuracy of 83.55%, and FPG levels above 86.85 mg/dl with a sensitivity of 69.57%, specificity of 61.78%, with a diagnostic accuracy of 62.66%. The calculated odds ratio (OR) for HbA1c > 5.6% and FPG > 86 mg/dl were 4.69 (95% CI: 2.66–8.29), and 3.7 (95% CI: 2.15–6.35), respectively. HbA1c and FPG combined had improved the predictive capability for GDM (OR: 7.26, 95% CI: 3.71–14.19). According to correlation analyses, a noteworthy positive correlation was found between HbA1c and, FPG, 50 g GCT, age, BMI, parity, and birth weight. However, there was no correlation between FPG and birth weight. Conclusion Diagnostic accuracy of HbA1c for GDM prediction in Turkish women with a low-risk pregnancy is 83.55% with a very good negative predictive value of 91.49%. HbA1c and FPG combined enhanced the predictive capability for GDM. In addition, there is a positive relationship between HbA1c and 50 g GCT, and birth weight. However, to suggest HbA1c as a potential screening test for gestational diabetes mellitus, further research is warranted.

Late-pregnancy dysglycemia in obese pregnancies after negative testing for gestational diabetes and risk of future childhood overweight: An interim analysis from a longitudinal mother-child cohort study.

BackgroundMaternal pre-conception obesity is a strong risk factor for childhood overweight. However, prenatal mechanisms and their effects in susceptible gestational periods that contribute to this risk are not well understood. We aimed to assess the impact of late-pregnancy dysglycemia in obese pregnancies with negative testing for gestational diabetes mellitus (GDM) on long-term mother–child outcomes.Methods and findingsThe prospective cohort study Programming of Enhanced Adiposity Risk in Childhood–Early Screening (PEACHES) (n = 1,671) enrolled obese and normal weight mothers from August 2010 to December 2015 with trimester-specific data on glucose metabolism including GDM status at the end of the second trimester and maternal glycated hemoglobin (HbA1c) at delivery as a marker for late-pregnancy dysglycemia (HbA1c ≥ 5.7% [39 mmol/mol]). We assessed offspring short- and long-term outcomes up to 4 years, and maternal glucose metabolism 3.5 years postpartum. Multivariable linear and log-binomial regression with effects presented as mean increments (Δ) or relative risks (RRs) with 95% confidence intervals (CIs) were used to examine the association between late-pregnancy dysglycemia and outcomes. Linear mixed-effects models were used to study the longitudinal development of offspring body mass index (BMI) z-scores. The contribution of late-pregnancy dysglycemia to the association between maternal pre-conception obesity and offspring BMI was estimated using mediation analysis. In all, 898 mother–child pairs were included in this unplanned interim analysis. Among obese mothers with negative testing for GDM (n = 448), those with late-pregnancy dysglycemia (n = 135, 30.1%) had higher proportions of excessive total gestational weight gain (GWG), excessive third-trimester GWG, and offspring with large-for-gestational-age birth weight than those without. Besides higher birth weight (Δ 192 g, 95% CI 100–284) and cord-blood C-peptide concentration (Δ 0.10 ng/ml, 95% CI 0.02–0.17), offspring of these women had greater weight gain during early childhood (Δ BMI z-score per year 0.18, 95% CI 0.06–0.30, n = 262) and higher BMI z-score at 4 years (Δ 0.58, 95% CI 0.18–0.99, n = 43) than offspring of the obese, GDM-negative mothers with normal HbA1c values at delivery. Late-pregnancy dysglycemia in GDM-negative mothers accounted for about one-quarter of the association of maternal obesity with offspring BMI at age 4 years (n = 151). In contrast, childhood BMI z-scores were not affected by a diagnosis of GDM in obese pregnancies (GDM-positive: 0.58, 95% CI 0.36–0.79, versus GDM-negative: 0.62, 95% CI 0.44–0.79). One mechanism triggering late-pregnancy dysglycemia in obese, GDM-negative mothers was related to excessive third-trimester weight gain (RR 1.72, 95% CI 1.12–2.65). Furthermore, in the maternal population, we found a 4-fold (RR 4.01, 95% CI 1.97–8.17) increased risk of future prediabetes or diabetes if obese, GDM-negative women had a high versus normal HbA1c at delivery (absolute risk: 43.2% versus 10.5%). There is a potential for misclassification bias as the predominantly used GDM test procedure changed over the enrollment period. Further studies are required to validate the findings and elucidate the possible third-trimester factors contributing to future mother–child health status.ConclusionsFindings from this interim analysis suggest that offspring of obese mothers treated because of a diagnosis of GDM appeared to have a better BMI outcome in childhood than those of obese mothers who—following negative GDM testing—remained untreated in the last trimester and developed dysglycemia. Late-pregnancy dysglycemia related to uncontrolled weight gain may contribute to the development of child overweight and maternal diabetes. Our data suggest that negative GDM testing in obese pregnancies is not an “all-clear signal” and should not lead to reduced attention and risk awareness of physicians and obese women. Effective strategies are needed to maintain third-trimester glycemic and weight gain control among otherwise healthy obese pregnant women.

Peripheral deiodinase activity: A potential explanation for the association between maternal weight and gestational hyperglycemia.

High maternal weight is known to associate with both low free thyroxine and gestational diabetes mellitus. We explore a deiodinase-related mechanism that may help explain these associations. Among 108 women receiving routine oral glucose tolerance testing for gestational diabetes mellitus, we collected biophysical data and measured free thyroxine and total triiodothyronine, using residual plasma samples. Fasting triiodothyronine/free thyroxine ratio and triiodothyronine were higher among women with gestational diabetes mellitus (p = 0.02; p = 0.04). The triiodothyronine/free thyroxine ratio and triiodothyronine measurements at 2 h were associated with weight (r = 0.20, p = 0.04; r = 0.22, p = 0.02); free thyroxine showed a non-significant inverse weight relationship (r = -0.06, p = 0.55). Glucose at all four intervals was associated with triiodothyronine/free thyroxine ratios, and triiodothyronine at 2 h. In stepwise regression, triiodothyronine/free thyroxine ratio predicted glucose more strongly than did weight. These relationships may be explained by higher maternal weight inducing peripheral deiodinase activity, resulting in higher plasma glucose (via triiodothyronine stimulation) and thereby increasing gestational diabetes mellitus risk.

Isolated polyhydramnios in the third trimester: is a gestational diabetes evaluation of value?*

We evaluated implications of testing for gestational diabetes mellitus (GDM) in pregnancies complicated by third trimester isolated polyhydramnios with previous negative diabetes screening test. In this retrospective cohort study of 104 pregnant women with polyhydramnios between 2005 and 2013, all had normal first trimester fasting glucose and normal glucose challenge test (GCT < 140 mg/dL). Late onset GDM was diagnosed in five women (4.8%) with isolated polyhydramnios, one abnormal value in the oral glucose tolerance test (OGTT) was identified in four additional women (3.8%). No significant differences were found in risk factors for GDM, mean second trimester GCT (117.5 vs. 107.2 mg/dL, p = 0.38) or fasting glucose values (82 vs. 86 mg/dL, p = 0.29) between women in the polyhydramnios group with and without late GDM diagnosis. Moreover, no significant difference was found in relation to the mode of delivery or birth weight between the studied groups (3437 ± 611 vs. 3331 ± 515 g, p = 0.63). Diagnosis of third trimester polyhydramnios was not associated with increased risk for GDM or neonatal complications.

Evaluation of 75 g glucose load in non-fasting state [Diabetes in Pregnancy Study group of India (DIPSI) criteria] as a diagnostic test for gestational diabetes mellitus.

Background & objectives:There is no consensus regarding optimal standard for diagnosis of gestational diabetes mellitus (GDM). In this study, use of 75 g glucose load in non-fasting state [Diabetes in Pregnancy Study Group of India (DIPSI) criteria] as a diagnostic test for GDM in pregnant women was compared with different oral glucose tolerance tests (OGTTs).Methods:This prospective study included 936 pregnant women, who underwent plasma glucose evaluation two hours after the challenge of 75 g glucose load irrespective of the timing of last meal (DIPSI criteria for GDM). After three days, standard 75 g OGTT was done in all women irrespective of previous plasma glucose value. Accuracy of the first result was compared to OGTT using cut-offs as per the World Health Organization (WHO) and International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria for the diagnosis of GDM.Results:Of the total 936 pregnant women, 73 (7.8%) patients had plasma glucose value ≥140 mg/dl when measured two hours after glucose load. When comparing with the WHO and IADPSG criteria, the sensitivity values were 65.1 and 74.1 per cent, respectively, and the corresponding specificity values were 96.3 and 96.9 per cent, respectively. On comparing with the WHO OGTT, only 41 of the 73 (56.2%) were true positives, whereas when IADPSG criteria were used, true positives were 46 (63%). False negative cases were also present when classified by the WHO and IADPSG criteria though in lesser numbers than false positives. The positive predictive values (PPVs) for the WHO and IADPSG criteria were 56.1 and 63 per cent, respectively, and their corresponding negative predictive values were 97.7 and 97.9 per cent, respectively.Interpretation & conclusions:Our findings showed that when 75 g glucose load in non-fasting state was used as a diagnostic test for GDM, almost one quarter of patients with GDM escaped diagnosis as sensitivity values were low. On the other hand, some GDM cases were falsely labelled as normal as this test did not account for cases of fasting hyperglycaemia. In addition, comparison with other OGTTs showed low PPVs. Hence, use of DIPSI criteria for diagnosing GDM must be reconsidered till further validation.

494: Positivity thresholds of HbA1c assay as a screening test for gestational diabetes mellitus in the first trimester in high-risk populations

494: Positivity thresholds of HbA1c assay as a screening test for gestational diabetes mellitus in the first trimester in high-risk populations

Survey on testing for gestational diabetes mellitus in Australia.

We surveyed members of National Association of Diabetes Centres (NADC) assessing use of new Australasian Diabetes In Pregnancy Society (ADIPS) and Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) Gestational Diabetes Mellitus (GDM) diagnostic guidelines in Australia. We found piecemeal adoption of recommended changes, with cessation of the 50g glucose challenge test (GCT) universal, early screening implementation common, but by varied methodologies, and new diagnostic criteria acceptance far from complete with significant workload increases almost universal.