Oral glucose tolerance testing at gestational weeks < or =16 could predict or exclude subsequent gestational diabetes mellitus during the current pregnancy in high risk group

Global burden of early pregnancy gestational diabetes mellitus (eGDM): A systematic review

AIMS

Gestational diabetes mellitus (GDM) diagnosed during the first trimester of pregnancy is called 'early pregnancy Gestational Diabetes Mellitus' (eGDM). The burden of eGDM has only been studied sporadically. This review aims to understand the global burden of eGDM in terms of prevalence, risk factors, pregnancy outcomes, treatment and postpartum dysglycemia.  METHODS: A review of epidemiologic studies reporting on early GDM screening as per Joanna Briggs Institute (JBI) methodology for prevalence reviews was conducted. A customized search strategy was used to search electronic databases namely, PubMed, CINAHL, EMBASE, Cochrane Library, Scopus, MEDLINE, Ovid, ScienceDirect, and Google Scholar. Three independent reviewers reviewed studies using Covidence software. Observational studies irrespective of study design and regardless of diagnostic criteria were included. Quality of evidence was appraised, and findings were synthesized.

RESULTS

Of 58 included studies, 41 reported a prevalence of eGDM, ranging from 0.7 to 36.8%. Body mass index (BMI), previous history of GDM, family history of diabetes and multiparity were reported as eGDM risk factors. Adverse pregnancy outcomes associated with eGDM were macrosomia, caesarean delivery, induction of labour, hypertension, preterm delivery, and shoulder dystocia. The incidence of postpartum dysglycemia and the need for insulin was higher in women with eGDM. The risk of bias was moderate. Heterogeneity of studies is a limitation. Meta-analysis was not performed.

CONCLUSIONS

There is heterogeneity in the prevalence of eGDM and intrapartum and postpartum ill effects for the mother and the offspring. There is a need to develop a universal screening protocol for eGDM.

Repeated oral glucose tolerance tests in women at risk for gestational diabetes mellitus

OBJECTIVE

Pregnant women with a negative oral glucose tolerance test (OGTT) between 24-28 weeks as part of risk-based screening for gestational diabetes mellitus (GDM) may develop clinical signs or symptoms suggestive for GDM in the third trimester. We aimed to determine the additional yield of repeating an OGTT to detect missed GDM in this group and assess patient characteristics and indications associated with a positive second OGTT.

STUDY DESIGN

We conducted a retrospective cohort study of women with a negative OGTT between 24-28 weeks of pregnancy in two hospitals in the Netherlands. Patient characteristics, pregnancy outcomes, OGTT results and indications were compared between women with normal (non-GDM) and abnormal (GDM) results of the second OGTT, using the WHO 1999 criteria (fasting glucose ≥7.0 mmol/L or 2 -h post load ≥7.8 mmol/L). We used receiver operating characteristic (ROC) curve analysis to determine cut-offs for fasting and 2 -h glucose values of the index OGTT that were associated with a positive OGTT in the third trimester.

RESULTS

Of 3147 women at risk for GDM, 183 underwent a second OGTT in the third trimester following their regular OGTT at 24-28 weeks. In 43 women (23.5%) GDM was diagnosed based on the second OGTT. A history of GDM was associated with subsequent GDM diagnosis, with an odds ratio of 2.6 (95% CI 1.0-6.3). Both fasting and 2 -h post load glucose values of the index OGTT were significantly higher in women with abnormal OGTT results later in pregnancy. Index OGTT glucose value cut-offs of 4.8 mmol/L (fasting) and 6.5 mmol/L (2 -h) had positive predictive values of 0.32 and 0.47 for a positive OGTT in the third trimester, and negative predictive values of 0.83 and 0.90, respectively. Fetal growth as a clinical symptom for GDM was the most frequent indication for repeating the OGTT, resulting in the diagnosis of GDM in 22.7% of women tested for this indication.

CONCLUSION

Repeating an OGTT after initial negative screening results in additional GDM diagnoses. In case of clinical signs, especially in women with additional risk factors such as a history of GDM or higher index OGTT glucose values, repeating an OGTT could be considered.

Effects of hereditary moderate high fat diet on metabolic performance and physical endurance capacity in C57BL/6 offspring

Obesity in pregnant women presents a risk to fetal health, leading to numerous metabolic syndromes and chronic inflammation risks. Previously, physical exercise was considered to be one of the primary treatments for obesity. However, the effect of fat consumption throughout the life cycle on physical endurance capacity remains unknown. A total of two groups of female mice (age, 6 weeks; C57BL/6J) were fed with a normal chow diet and a moderate high fat diet (MHFD), during pregnancy and lactation (8 weeks), with the offspring receiving the same diet as the mother. When filial mice were 8, 16 and 24 weeks old, they were tested for endurance, blood pressure (BP) and glucose tolerance, as well as adipose tissue infiltration and macrophage subtype. Compared with the control group, filial mice in MHFD groups exhibited increased BP and glucose levels and larger adipose cells (~4‑fold). During adolescence, the obese filial mice demonstrated increased endurance compared with controls. Endurance declines in middle and old age; the endurance of aged obese mice was 29% that of lean ones. In addition, body coordination and movement memory did not notably change. The expression of cluster of differentiation 68, one of the most reliable markers of macrophages, increased by 2.48‑fold, demonstrating that macrophages were recruited and underwent infiltration. In addition, increased tumor necrosis factor‑α and decreased interleukin‑10 expression demonstrated that infiltrated macrophages are polarized to the M1 state, which weakens physical endurance and resists type M2 macrophages, which exhibit repairing functions. In conclusion, hereditary MHFD weakens physical endurance and alters the metabolic characteristics of C57BL/6 offspring.

Clinical significance of second-trimester 50-g glucose challenge test among Japanese women diagnosed as normoglycemic after first-trimester 75-g glucose tolerance test

OBJECTIVE

This study was performed to determine how often Japanese women diagnosed as normoglycemic on first-trimester 75-g glucose tolerance test (75gGTT) later develop gestational diabetes mellitus (GDM).

MATERIAL AND METHODS

Sixty-two women with random plasma glucose (PG) level ≥ 105 mg/dL during the first trimester and subsequent first-trimester diagnosis of normoglycemia with 75gGTT underwent 50-g glucose challenge test (50gGCT) during the second trimester. Twenty-one with a positive 50gGCT result (60-m PG ≥ 140 mg/dL) underwent second-trimester 75gGTT. First-trimester random PG levels and 75gGTT results were compared between 21 and 41 women with positive and negative 50gGCT results, respectively. Changes in immunoreactive insulin (IRI) associated with 75gGTT were determined simultaneously.

RESULTS

All 21 women with a positive 50gGCT result showed normoglycemia on second-trimester 75gGTT. Thus, none of the 62 women developed GDM. Insulin resistance increased significantly in the 21 women with 75gGTT during the first and second trimesters, as indicated by increases in homeostasis model assessment for insulin resistance (HOMA-IR) and homeostasis model assessment for β-cell function (HOMA-β) with no significant changes in preload or afterload PG levels. Neither random PG levels (116 ± 12 vs. 116 ± 12 mg/dL, respectively) nor 75gGTT results (86 ± 6 vs. 84 ± 5 mg/dL for 0-minute [0-m] PG level, 130 ± 28 vs. 131 ± 25 mg/dL for 60-m PG, and 111 ± 19 vs. 118 ± 18 mg/dL for 120-m PG, respectively) during the first trimester differed significantly between the 41 and 21 women with negative and positive second-trimester 50gGCT results, respectively.

CONCLUSION

Although insulin resistance increased in the second trimester, risk of developing GDM was < 1/62 among Japanese women in whom hyperglycemia was excluded with first-trimester GTT.

Early Diagnosis of Gestational Diabetes Mellitus (EDoGDM) study: a protocol for a prospective, longitudinal cohort study

INTRODUCTION

A diagnosis of gestational diabetes mellitus (GDM) in low-risk pregnant women is based on an oral glucose tolerance test (OGTT) between 24 and 28 gestational weeks. However, there is insufficient evidence for why the test is performed in this time period. Moreover, the fetus may be exposed to hyperglycaemia prior to the current testing time frame, making earlier administration potentially advantageous. The main purpose of the present study is to investigate the GDM diagnostic value of an OGTT performed at 18-20 gestational weeks. The results of the study may provide scientific insight into the most beneficial time of OGTT for pregnant women.

METHODS AND ANALYSIS

As a prospective, longitudinal cohort study, the Early Diagnosis of Gestational Diabetes Mellitus (EDoGDM) study will recruit 570 pregnant women who meet the inclusion and exclusion criteria outlined below. OGTTs will be performed between 18 and 20 gestational weeks (early OGTT) and 24-28 gestational weeks (regular OGTT). Clinical and laboratory information of the mother and their offspring will be collected for analysis. The prevalence of GDM at 18-20 gestational weeks will be described, and the sensitivity, specificity, positive predictive value and negative predictive value of early OGTT on diagnosis of GDM will be studied. Clinical outcomes associated with hyperglycaemia will be compared between groups diagnosed by early or regular OGTT.

ETHICS AND DISSEMINATION

The study was approved by The Ethical Committees of The First Affiliated Hospital of Sun Yat-sen University (number 2016-042). Signed informed consent will be obtained from all participants. The results of this study will be disseminated in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02740283.

Prevalence of Gestational Diabetes Mellitus in urban and rural Tamil Nadu using IADPSG and WHO 1999 criteria (WINGS 6)

BACKGROUND

To determine the prevalence of Gestational Diabetes Mellitus (GDM) in urban and rural Tamil Nadu in southern India, using the International Association of Diabetes and Pregnancy Study Groups (IADPSG) and the World Health Organization (WHO) 1999 criteria for GDM.

METHODS

A total of 2121 pregnant women were screened for GDM from antenatal clinics in government primary health centres of Kancheepuram district (n = 520) and private maternity centres in Chennai city in Tamil Nadu (n = 1601) between January 2013 to December 2014. Oral glucose tolerance tests (OGTT) were done after an overnight fast of at least 8 h, using a 75 g glucose load and venous samples were drawn at 0, 1 and 2 h. GDM was diagnosed using both the IADPSG criteria as well as the WHO 1999 criteria for GDM.

RESULTS

The overall prevalence of GDM after adjusting for age, BMI, family history of diabetes and previous history of GDM was 18.5 % by IADPSG criteria with no significant urban/rural differences (urban 19.8 % vs rural 16.1 %, p = 0.46). Using the WHO 1999 criteria, the overall adjusted prevalence of GDM was 14.6 % again with no significant urban/rural differences (urban 15.9 % vs rural 8.9 %, p = 0.13).

CONCLUSION

The prevalence of GDM by IADPSG was high both using IADPSG as well as WHO 1999 criteria with no significant urban/rural differences. This emphasizes the need for increasing awareness about GDM and for prevention of GDM in developing countries like India.

Prediction of gestational diabetes mellitus in the first trimester, comparison of fasting plasma glucose, two-step and one-step methods: a prospective randomized controlled trial

Our aim was to evaluate and compare the diagnostic performance of three methods commonly used for GDM screening: fasting plasma glucose (FPG), two-step 50 g glucose challenge test (GCT), and 75 g glucose tolerance test (GTT) in a randomized study design to predict GDM in the first trimester and determine the best approach in predicting GDM. In a non-blind, parallel-group prospective randomized controlled study; 736 singleton pregnant women underwent FPG testing in the first trimester and randomly assigned to two groups; two-step 50 g GCT and 75 g GTT. GDM diagnosis was made according to Carpenter-Coustan or ADA (American Diabetes Association) criteria in two-step 50 g GCT and 75 g GTT groups, respectively. Subsequent testing was performed by two-step 50 g GCT at 24-28 weeks for screen negatives. After excluding the women who were lost to follow-up or withdrawn as a result of pregnancy loss, 486 pregnant women were recruited in the study. The FPG, two-step GCT, and one-step GTT methods identified GDM in 25/486 (5.1 %), 15/248 (6.0 %), and 27/238 (11.3 %) women, respectively. Area under ROC curves were 0.623, 0.708, and 0.792, respectively. Sensitivities were 47.17, 68.18, and 87.1 %, respectively. Specificities were 77.37, 100, and 100 %, respectively. Positive predictive values were 20.33, 100, and 100 %, respectively. Negative predictive values were 92.29, 97, and 98.1 %, respectively. Until superior screening alternatives become available, the 75 g GTT may be preferred for GDM screening in the first trimester.

Prenatal care: touching the future

The provision of preconception and prenatal care is a critical and time-honored role for family physicians. It could even be termed the first preventive care a human being receives. It has been suggested by some studies that, because of the continuity of care that is considered a cornerstone of family practice, family physicians provide prenatal care that may improve birth outcome. Although prenatal care is acknowledged as important for a healthy pregnancy and delivery, there is debate regarding the true efficacy of prenatal care.

Gestational diabetes mellitus (GDM) screening in morbidly obese pregnant women

OBJECTIVE

To study the outcomes of two-stage GDM screening of morbidly obese women in our obstetric unit and to evaluate the diagnostic performance of 20-week oral glucose tolerance test (OGTT) values in predicting or excluding late onset GDM.

STUDY DESIGN

A retrospective study in which 190 pregnant women with BMI ≥40 had two-stage screening: a 75g OGTT is performed at 20 weeks and repeated at 28 weeks if the 20-week OGTT was normal. Receiver operating characteristic (ROC) curves for 20-week OGTT values were constructed in order to obtain an optimal cut-off value of fasting and/or 2-h glucose at 20 weeks from which GDM could be predicted or excluded at 28 weeks. Sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were determined for each of the fasting and 2-h post-load glucose values at 20 weeks.

RESULTS

Forty six (24%) women were diagnosed with GDM. Thirty-two (70%) were diagnosed at 20 weeks and 14 (30%) at 28 weeks. The 2-h cut-off value of ≥6mmol/l at the 20-week OGTT had a negative likelihood ratio of 0.12 to predict GDM at 28 weeks. The low negative likelihood ratio reduces the probability of detecting GDM at 28 weeks from 9% (pre-test probability) to 1% (post-test probability).

CONCLUSION

Nearly 70% of the women were diagnosed with GDM at 20 weeks, which gives an early opportunity to treat maternal hyperglycaemia with consequent health benefits. A 2-h cut-off glucose value of 6mmol/l at 20 weeks OGTT has a low negative likelihood ratio which virtually excludes GDM at 28 weeks. Hence women with a 2h value of <6mmol/l at 20 weeks can avoid a repeat 28 week OGTT test.

When should screening be performed for gestational diabetes?

AIM

To consider the arguments for screening outside the standard screening period of 24 to 28 weeks of gestation.

MATERIALS AND METHODS

A search of the literature between 1990 and 2010 was performed using the PubMed® and Cochrane® databases. Recommendations from learned societies in diabetology and obstetrics & gynaecology were consulted.

RESULTS

Gestational diabetes mellitus screening is classically recommended between weeks 24 and 28 of pregnancy, the period during which glucose tolerance deteriorates. However, the increasing prevalence of type 2 diabetes in women of childbearing age with risk factors requires earlier screening. Fasting blood glucose should be measured at the fi rst visit during early pregnancy for these patients. The diagnostic threshold is the same as for patients who are not pregnant, i.e. blood glucose > 1.26 g/l. However, the benefit of screening for gestational diabetes during early pregnancy for women with risk factors has not been supported by prospective studies. Therefore oral glucose tolerance testing during early pregnancy is not currently recommended for the detection of gestational diabetes. Screening for gestational diabetes, regardless of the recommended screening policy, must be performed between weeks 24 and 28 of pregnancy. There are no reasons to consider subsequent screening for gestational diabetes at a later stage.

The "hypertriglyceridemic waist" phenotype and glucose intolerance in pregnancy

BACKGROUND

Abdominal visceral adiposity in early pregnancy has been associated with impaired glucose tolerance in later pregnancy. The "hypertriglyceridemic waist" phenotype (i.e., abdominal obesity in combination with hyper-triglyceridemia) is a clinical marker of visceral obesity. Our study aimed to assess the association between the hyper-triglyceridemic-waist phenotype in early pregnancy and glucose intolerance in later pregnancy.

METHODS

Plasma triglycerides and waist girth were measured at 11-14 weeks of gestation among 144 white pregnant women. Glycemia was measured following a 75-g oral glucose tolerance test performed at 24-28 weeks of gestation.

RESULTS

A waist girth greater than 85 cm in combination with a triglyceride level ≥ 1.7 mmol/L in the first trimester was associated with an increased risk of two-hour glucose ≥ 7.8 mmol/L following the 75-g oral glucose tolerance test (odds ratio [OR] 6.1, p = 0.002). This risk remained significant even after we controlled for maternal age, fasting glucose at first trimester and previous history of gestational diabetes (OR 4.7, p = 0.02).

INTERPRETATION

Measurement of waist girth in combination with measurement of triglyceride concentrations in the first trimester of pregnancy could improve early screening for gestational glucose intolerance.

Longitudinal changes of adiponectin, carbohydrate and lipid metabolism in pregnant women at high risk for gestational diabetes

To evaluate, in pregnant women at high risk for gestational diabetes (GDM), the longitudinal changes of adiponectin, carbohydrate and lipid metabolism, and to assess their independent value as risk factors for the development of GDM. Fifty women at beginning of pregnancy were studied. Adiponectin, insulin sensitivity (homeostasis model assessment, HOMA) and lipid panel were measured at 1st, 2nd and 3rd trimesters of pregnancy. Twelve patients developed GDM. In both groups, GDM and normal glucose tolerance (NGT), adiponectin decreased from 1st to 2nd and 3rd trimesters by about 5 and 20% (GDM, p < 0.05), and of about 17 and 25% in NGT (p < 0.05), respectively. Values observed in NGT were similar to those of GDM (F = 9.401; p = 0.238). The Cox regression model identified as the strongest independent risk factor for GDM HOMA over 1.24 (RR = 14.12) at 1st trimester, fasting glycaemia over 87 mg/dl (RR = 42.68) triglycerides over 158 mg/dl (RR = 5.87) and body mass index (BMI) over 27 kg/m(2) (RR = 4.38) at 2nd trimester. Adiponectin in high-risk women is characterised by a constant reduction throughout gestation, irrespective of the development of GDM. HOMA, fasting glycaemia, triglycerides and BMI, but not adiponectin are independent predictors of GDM.