Can either oral glucose challenge test or oral glucose tolerance test parameters predict gestational diabetes mellitus?

This study aims to evaluate the relationship between the glucose challenge test (GCT) levels and any of the oral glucose tolerance test (OGTT) parameters (fasting plasma glucose (FPG), 1-, 2-, or 3-h plasma glucose levels) and their effect on predicting gestational diabetes mellitus (GDM). This analysis was carried out as a retrospective study at Obstetrics and Gynecology Clinic of Turgut Özal University Hospital. Oral GCT were conducted on patients who are at 24–29 weeks’ gestation. The study participants with positive GCT results underwent a 3-h, 100-g OGTT, and the resulting values were evaluated using Carpenter and Coustan diagnostic criteria to determine the gestational glucose tolerance status of patients. The data obtained from both tests (GCT, FPG, 1-, 2-, 3-h OGTT values) were analyzed to observe the effect of each group on predicting GDM. Although all of the GCT and OGTT values were found to be statistically significant (p?<?0.001) in determining GDM, the 2-h values of OGTT detected almost all GDM cases with a very high sensitivity level (94.5 %). The 1-h values on the other hand identified 87.6 % of GDM (p?<?0.001). The GCT value with the highest sensitivity and specificity for predicting GDM was calculated as 154.50 mg/dl (sensitivity and specificity rates were 79.2 and 72.8 %, respectively). A 2-h OGTT glucose level can detect GDM with 94.5 % sensitivity. This result can guide clinicians to evaluate the patients with GDM.     

A single test procedure to diagnose gestational diabetes mellitus

Universal screening for gestational diabetes mellitus (GDM), detects more cases and improves maternal and offspring prognosis. Of all the screening tests, World Health Organization (WHO) procedure is simple and cost effective; the only disadvantage is that the pregnant woman has to come in the fasting state to undergo oral glucose tolerance test (OGTT). Hence, we undertook a study to elucidate a test that is casual and reliable to diagnose GDM. A total of 800 pregnant women underwent 75-g glucose challenge test (GCT) irrespective of the time of the last meal and their 2-h plasma glucose (PG) was estimated. They also underwent a 2-h 75-g OGTT recommended by WHO after 72 h. There was no statistically significant difference in the glycemic profile between GCT and WHO OGTT in the diagnosis of GDM. In conclusion, GCT performed irrespective of the last meal timing is a patient-friendly approach and causes least disturbance in the pregnant woman's routine activities.     

Gestational diabetes screening of a multiethnic, high-risk population using glycated proteins

In populations with a high incidence of gestational diabetes (GDM), any form of oral glucose testing for screening or diagnosis excessively strains the health care system. We investigated the value of glycated proteins as potential screening tests in 430 pregnant women, i.e. protein corrected fructosamine (cFRUC) and hemoglobin A1c (HbA(1c)) both alone and in combination for a GDM diagnosis confirmed by the 'gold standard' 100-g oral glucose tolerance test (OGTT). Two cut-off values were used for each test, the upper to rule in and the lower to rule out GDM. At the lower cut-off values for cFRUC of 210 micromol/l and HbA(1c) of 5%, the sensitivities achieved were 92.2 and 92.1% while the negative predictive values were 88.9 and 86.9%, respectively. The upper cut-off values did not achieve acceptable positive predictive values to be useful for ruling in GDM. Screening of our multiethnic, high-risk pregnant population with a combination of cFRUC and HbA(1c) on a single fasting sample would have avoided the cumbersome OGTT (by ruling out GDM) in 37.9% women with only a 3.9% misclassification rate. This potentially simpler approach, though not universally applicable, would be clinically useful and more acceptable to patients in selected high-risk populations.     

Comparison of National Diabetes Data Group and World Health Organization criteria for detecting gestational diabetes mellitus

Summary We compared the criteria for diagnosis of gestational diabetes mellitus (GDM) of the National Diabetes Data Group (NDDG) and the World Health Organization (WHO) and studied the outcomes of pregnancy. A 50-g glucose screening test and 75-g oral glucose tolerance test (OGTT) were scheduled for 709 pregnant women in the same week between the 24th and 28th week of pregnancy. Blood glucose was measured 1 h after the 50-g glucose screening test and if found to be 7.8 mmol/l or more, a 100-g OGTT was scheduled within 7 days after a 75-g OGTT. The prevalence of GDM was found to be 1.4% (10/709) and 15.7% (111/709) by NDDG and WHO criteria (2 h 7.8 mmol/l), respectively. Using NDDG criteria, all the GDM patients had abnormal 75-g OGTT by WHO criteria. NDDG and WHO criteria were significantly different when compared with normal OGTT by each criteria for age, BMI, pregnancy-induced hypertension, Caesarian delivery, macrosomia and neonatal hypoglycaemia. Of 14 women with macrosomic infants 6 had an abnormal WHO test while only 3 of 14 had an abnormal NDDG test. These findings suggest that WHO criteria GDM patients had significantly worse outcomes of pregnancy and fewer perinatal complications were missed than with the more cumbersome NDDG criteria, and no case of GDM as diagnosed by NDDG criteria was missed.Abbreviations GDM Gestational diabetes mellitus - NDDG National Diabetes Data Group - WHO World Health Organization - OGTT oral glucose tolerance test - BMI body mass index     

Asymmetric dimethylarginine level in hyperglycemic gestation

We aimed to evaluate plasma asymmetric dimethylarginine (ADMA) concentrations and its relation with insulin sensitivity/resistance indices in pregnant women with different degrees of carbohydrate intolerance. This study included a two step approach; 50 g glucose challenge test (GCT) followed by 100 g oral glucose tolerance test (OGTT) was used for diagnosis of carbohydrate intolerance within 24-28th weeks of gestation. Pregnant women with positive GCT but negative OGTT (AGCT group, n=30) and gestational diabetics (GDM group, n=58) were compared to healthy pregnant controls (n=50). Plasma ADMA concentration and its relationship with glucose and insulin levels and insulin sensitivity/resistance indices (HOMA-IR, QUICKI, ISIOGTT) were evaluated. Both AGCT and GDM groups were found to have similarly higher plasma ADMA levels than control subjects (3.60±1.21; 4.00±1.70; 2.65±0.82 μmol/l, respectively, P=0.001). ADMA was significantly but slightly correlated with insulin sensitivity/resistance indices and moderately correlated with 2-h insulin level. The 2-h insulin value of the OGTT was the independent influencing constant for ADMA (R=0.57, P=0.0001). In conclusion, plasma asymmetric dimethylarginine level was higher in cases with abnormal glucose challenge test but normal OGTT as well as in gestational diabetics, compared to pregnant women with normal glucose tolerance. The elevated ADMA level in pregnant women with carbohydrate intolerance may possibly be due to elevated insulin level.     

Placental weight and placental weight-to-birth weight ratio are increased in diet- and exercise-treated gestational diabetes mellitus subjects but not in subjects with one abnormal value on 100-g oral glucose tolerance test

The aim of the present study was to determine whether the placental weight and placental weight-to-birth weight ratio (PW/BW) increased in pregnant women with one abnormal value (OAV) on 100-g oral glucose tolerance test (OGTT) and diet- and exercise-treated, non-insulin-requiring gestational diabetes mellitus (GDM) subjects. The 50-g glucose challenge test (GCT) was administered to 324 pregnant women. Women with abnormal 50-g test received a 100-g, 3-h OGTT using National Diabetes Data Group criteria. Women with GDM and OAV were treated with diet and exercise. Twenty subjects who required insulin or met exclusion criteria were excluded from the study. After the exclusion of 20 subjects, the GDM group consisted of 30 (9.7%) pregnant women and the OAV group consisted of 32 (9.9%) pregnant women. The control group consisted of 242 pregnant women. Birth weight (GDM: 3288.3+/-364.2 g; OAV: 3278.1+/-409.9 g; control group: 3270.6+/-346.5 g) did not differ significantly between groups (P>.05). Significantly higher placental weights (GDM: 694.8+/-152.1 g; OAV: 622.2+/-105.3 g; control group: 610.2+/-116.6 g; P<.01) and PW/BW (GDM: 0.21+/-0.03; OAV: 0.193+/-0.04; control group: 0.188+/-0.04; P<.01) were observed in GDM group compared to OAV and control group. No significant difference was found for OAV group in terms of placental weight and PW/BW compared to the control group. Our data indicated that women with OAV delivered infants and placenta of similar weight to those of normal pregnancies.     

Diagnostic criteria for diabetes mellitus and other categories of glucose intolerance: 1997 criteria by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus (ADA), 1998 WHO consultation criteria, and 1985 WHO criteria. World Health Organization.

To compare 1997 ADA diagnostic criteria for diabetes mellitus and other categories of glucose intolerance/1998 WHO Consultation criteria versus 1985 WHO criteria, we analyzed data from a 75-g oral glucose tolerance test (OGTT) performed on 1051 high-risk subjects without medical history of diabetes at Diabetes Screening Clinic, Ramathibodi Hospital, Thailand. There were 372 males and 679 females, aged (mean +/- S.D.) = 50.3 +/- 12.55 years, BMI = 25.62 +/- 4.39 kg/m2. If fasting plasma glucose (FPG) was used as recently recommended then 54.1, 20.4, and 25.5% of cases were classified as normal, impaired fasting glucose (IFG), and diabetic, respectively. In diagnosing diabetes using a full OGTT based on the 1985 WHO criteria as the reference test, FPG > or = 7 mmol/l had a sensitivity of 57.7%, specificity of 97.4%, positive predictive value of 94.0%, and negative predictive value of 76.4%; 53.7% of subjects with IFG had 2-h plasma glucose > or = 11.1 mmol/l. The 1997 ADA/1998 WHO Consultation criteria and 1985 WHO criteria for a full OGTT yield similar overall results. FPG ( > or = 7 mmol/l) was not sensitive for diagnosing diabetes. Moreover, about half of the subjects with IFG were actually diabetic. Therefore, OGTT remains a valuable test in diagnosing diabetes and classifying various categories of glucose intolerance.     

Prevalence and risk factors for gestational diabetes assessed by universal screening

In order to evaluate the prevalence of gestational diabetes mellitus (GDM) and the presence of risk factors for GDM, we conducted a retrospective study of a cohort of Italian women. In addition, we compared universal versus selective screening to validate the ADA's recommendations in our population. From June 1st, 1995 to December 31st, 2001, universal screening for GDM was performed in 3950 women. The glucose challenge test (GCT) was positive (GCT+) in 1389 cases (35.2%). The 1-h glucose level after GCT enabled us to diagnose GDM directly in 24 pregnant women. Oral glucose tolerance test (OGTT) was performed in 1221 GCT+ women (144 cases with GCT+ dropped out) and GDM was diagnosed in 284 (23.2%) of them. OGTT was also performed in 391 randomly chosen, women from the GCT negative (GCT-) group. In this last group 25 (6.3%) women had GDM. Thus, the total number of subjects with GDM was 333 out of 3806 with a prevalence of 8.74% in the entire cohort. Assuming that the rate of GDM observed in the random sample of GCT- women is applicable to the whole group of 2561 GCT- women, then 161 GCT- patients could also have GDM. This will further increase the estimated prevalence for the whole cohort up to 12.3% (i.e. 469 out of 3806 pregnant women). There were 236 (5.6%) women with a low risk for GDM (normal weight, age less than 25 years and without a family history of diabetes). In this group we found 34 cases and five cases with positive screening test and GDM, respectively. Thus, if we excluded low risk women from the screening test, as suggested by ADA recommendations, only five women with GDM would have been missed. However, about 95% of our population were at medium or high risk for GDM and, therefore, would have been screened. The rate of GDM was significantly higher in women with a positive history of diabetes, increasing age, previous pregnancies, pre-pregnancy overweight and short stature. After logistic regression analysis, GDM diagnosis was significantly correlated with age (P<0.0001), pre-pregnancy BMI (P<0.0001), weight gain (P<0.0001) and family history of diabetes (P<0.01).     

Maternal triglyceride levels and newborn weight in pregnant women with normal glucose tolerance.

OBJECTIVE: To determine the predictive value of serum triglyceride levels (TG) for neonatal weight in pregnant women with positive diabetic screening but normal glucose tolerance. RESEARCH DESIGN AND METHODS: We enrolled 180 pregnant Caucasian women with positive diabetic screening. All women underwent a 3-h 100-g oral glucose tolerance test (OGTT) at 27th +/- 4 week of gestation. At the time of OGTT, we measured: fasting plasma glucose, fasting lipids profile and determined ApoE polymorphisms to evaluate the effects on lipid levels. In 83 women with normal glucose tolerance and at term delivery we evaluated the association between maternal serum TG, specific maternal parameters known to affect fetal growth and newborn weight. RESULTS: Based on OGTT, gestational diabetes mellitus (GDM) was diagnosed in 36 women (20%), impaired glucose tolerance (IGT) in 23 (13%), and normal glucose tolerance (NGT) in 121 (67%). Serum TG concentration was significantly higher in women with GDM (2.47 +/- 0.77 mmol/l) as compared with NGT (1.99 +/- 0.64 mmol/l) or IGT (1.98 +/- 0.81 mmol/l) (P < 0.01). ApoE3 allelic frequency was 86%, ApoE2 and ApoE4 were 5 and 9%, respectively. We found no clear-cut association between apoE genotype and serum TG concentration. Macrosomia and LGA newborns were more frequent in IGT than in GDM or NGT (P < 0.01). In the 83 women with positive diabetic screening but normal glucose tolerance who delivered at term, the incidence of LGA infants was significantly higher in those with TG levels higher than the 75th percentile (> 2.30 mmol/l) (21%) than in mothers who had normal TG levels (4.5%) (P < 0.05). Pre-pregnancy BMI (r(2) = 0.067), weight gain during pregnancy (r(2) = 0.062), fasting serum TG (r(2) = 0.09), and 2-h post-OGTT glucose levels (r(2) = 0.044) were all associated with neonatal body weight (all P < 0.05 or less). However, on a multiple regression analysis, only pre-pregnancy BMI (F-test = 7.26, P < 0.01), and fasting serum TG (F-test = 4.07, P < 0.01) were independently associated with birth weight. CONCLUSIONS: Pre-pregnancy BMI and fasting maternal serum TG determined in the last trimester of gestation were independently associated with neonatal birth weight in women with normal glucose tolerance, but positive screening test. TG levels measured in the third trimester of pregnancy are independent of the genetic polymorphism of ApoE.     

Can plasma glucose and HbA1c predict fetal growth in mothers with different glucose tolerance levels?

To assess whether HbA1c and plasma glucose predicts abnormal fetal growth, 758 pregnant women attending 5 Diabetic Centers were screened for gestational diabetes mellitus (GDM). On glucose challenge (GCT) at 24-27 weeks of gestation (g.w.), negative cases formed the normal control group (N1). Positive cases took an oral glucose tolerance test (OGTT): those found negative were classed as false positives screening test (N2); if they had an OGTT result at least as high as their normal glucose levels, they were classed as having one abnormal glucose value (OAV) at OGTT; two values as GDM. HbA1c was assayed on the day of GCT. We considered fetal macrosomia, large for gestational age (LGA), ponderal index and mean growth percentile. Mean age, pre-pregnancy BMI, fasting plasma glucose (FPG) and HbA1c were progressively higher from N1 to GDM patients. The newborn of N2 mothers were heavier than those with N1 or GDM. The mean growth percentile was significantly higher in N2 than in N1. More LGA babies were born to OAV than to N1 or N2 women. Macrosomia and ponderal index did not differ significantly in the four groups. At logistic regression only plasma glucose at GCT could predict LGA babies and a ponderal index above 2.85. At risk analysis, GDM and OAV significantly predicted LGA babies, and GDM a ponderal index >2.85. In conclusion, FPG at GCT could predict fetal overgrowth and plasma glucose >85mg/dl doubles the risk of LGA infants. HbA1c at 24-27g.w. does not predict fetal overgrowth. Mild alterations in glucose tolerance correlate with fetal overgrowth and needs monitoring and treatment.     

Does parity increase insulin resistance during pregnancy?

AIMS: To study the effect of parity on impairment of insulin sensitivity during pregnancy and on the risk of gestational diabetes (GDM). METHODS: We studied the relationship between parity and peripheral insulin sensitivity index (ISI(OGTT)) or GDM in 1880 caucasian women, who underwent a 100-g, 3-h oral glucose tolerance test (OGTT) between the 24th and 28th gestational week and in 75 women who underwent an OGTT in two consecutive pregnancies. A proxy for beta-cell function (basal plasma C peptide/fasting plasma glucose; CP/FPG) was also measured. RESULTS: By univariate analysis parity was related to decreased ISI(OGTT) and to increased CP/FPG in those with parity > 3 and likewise GDM, diagnosed in 124 women (6.58%), was linearly related to parity (P = 0.0034) and strongly age dependent. The relationships between parity and ISI(OGTT), CP/FPG and GDM were no longer significant after adjustment for age, pregestational body mass index (BMI), and weight gain. GDM was significantly related to age and pregestational weight, while ISI(OGTT) and CP/FPG were inversely related to prepregnancy BMI or weight gain. In comparison with the index pregnancy, the subsequent pregnancy was characterized by an increase in actual and prepregnancy BMI, in 2 h area under curve (AUC) glucose and by a decrease in ISI(OGTT) (P = 0.0001). The longer the time interval between pregnancies and the higher the increment in pregestational BMI or in weight gain during the pregnancy, the greater were the ISI(OGTT) decrease and 2-h AUC glucose increase. CONCLUSIONS: Parity is not directly linked to insulin sensitivity deterioration, to CP/FPG increase during pregnancy, or to GDM appearance, although it is linked through the mediation of progressive ageing and weight gain either before or during pregnancy, when there is a sufficiently long time interval between pregnancies.     

A postnatal fasting plasma glucose is useful in determining which women with gestational diabetes should undergo a postnatal oral glucose tolerance test.

AIMS: It is recommended that women with gestational diabetes (GDM) should have a 6-week postnatal oral glucose tolerance test (OGTT). As this test may be unpleasant, time-consuming and has resource implications, we evaluated whether the 6-week postnatal fasting glucose could be used to determine which women should undergo an OGTT. METHODS: All women with GDM, diagnosed according to the World Health Organization criteria, who were delivered at the Princess Anne Hospital, Southampton between May 2000 and May 2002, were recommended to have an OGTT. The results of the fasting plasma glucose concentration were assessed in relation to the 2-h glucose value. RESULTS: One-hundred and fifty-two women with GDM were delivered. Thirty (19.7%) women refused an OGTT or failed to attend. In the 122 OGTTs, three (2.4%; 95% confidence interval 0.8, 7) women had diabetes, three had impaired glucose tolerance and four had impaired fasting glycaemia. No woman with a normal test had fasting glucose of > or =6.0 mmol/l. Fasting glucose was correlated with the 2-h glucose (r=0.62, P<0.0001). Only 10 (8.1%) of the OGTTs would have been performed if only women with fasting glucose of > or =6.0 mmol/l underwent the test. The sensitivity and specificity of this approach for the diagnosis of postnatal diabetes is 100% and 94%, respectively. Linear regression methods indicate that it would miss fewer than three in 10 000 cases. CONCLUSIONS: In our population, a 6-week postnatal fasting plasma glucose is useful in determining which women with gestational diabetes should undergo an OGTT. Consequently we now perform OGTT only in women whose postnatal fasting plasma glucose is > or =6.0 mmol/l.     

Comparison of screening for gestational diabetes mellitus by oral glucose tolerance tests done in the non-fasting (random) and fasting states

Aim

The Diabetes in Pregnancy Study Group of India (DIPSI) guidelines recommend the non-fasting 75-g oral glucose tolerance test (OGTT) as a single-step screening and diagnostic test for gestational diabetes mellitus (GDM). The aim of this study was to compare the DIPSI criteria with the World Health Organization (WHO) 1999 and the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria for GDM.

Methods

A total of 1,031 pregnant women attending antenatal clinics in urban and rural Tamil Nadu, India, underwent a 75-g OGTT in both non-fasting and fasting states, 2–3 days apart. Venous plasma glucose was measured using an autoanalyser, and GDM was diagnosed by DIPSI, WHO 1999 and IADPSG criteria.

Results

Of the 83 women identified to have GDM by WHO 1999 criteria, only 23 were diagnosed by DIPSI criteria. Of the 106 women diagnosed to have GDM by the IADPSG criteria, only 24 were diagnosed by DIPSI. The DIPSI non-fasting OGTT 2-h VPG cut point of 140 mg/dl (7.8 mmol/l) had a very low sensitivity when compared to the WHO 1999 criteria (sensitivity 27.7 %, specificity 97.7 %) and IADPSG criteria (sensitivity 22.6 %, specificity 97.8 %).

Conclusions

The DIPSI non-fasting OGTT criteria cannot be recommended for diagnosis of GDM due to its low sensitivity. Thus, as a single-step diagnostic test for GDM, the fasting OGTT needs to be done. When this is not possible, the well-established two-step procedure using the 50-g glucose challenge test as an initial screening test, followed by the diagnostic fasting OGTT, can be continued.     

Diagnostic criteria for gestational diabetes in relation to pregnancy outcome

OBJECTIVES: To determine which of the American Diabetes Association (ADA) or World Health Organization (WHO) plasma glucose criteria for gestational diabetes mellitus (GDM) best predicts poor fetal outcome. To determine whether an alternative cut-off point would result in increased predictive value and greater diagnostic effectiveness in pregnancies at high risk for GDM. RESEARCH DESIGN AND METHODS: A sample of 473 successive apparently normal pregnant women attending the Obstetric Department were screened for GDM using both the ADA and the WHO criteria. Between 26 and 30 weeks of gestation, they underwent, on subsequent days, a screening test with a 50-g oral glucose load and two oral glucose tolerance tests (OGTTs) with 75 and 100 g of glucose according to the WHO and the ADA recommendations, respectively. From this group, we identified 99 women at high risk for GDM, who did not attend their pregnancy follow-up and whose delivery records were recovered at our hospital or in neighbouring hospitals. This unusual situation enabled us to study the natural history and outcome of their pregnancy in spite of not receiving special management usually provided to such women. As macrosomia was expected to be the most frequent undesirable foetal outcome, sensitivity and specificity calculations have been based on this outcome. RESULTS: The study population (n=99) had a median parity of two and 14% had abnormal results in the 2-h, 75-g load test (WHO) vs. 6% in the 100-g test (ADA). Optimal cut-off points for each test were lower than those recommended for diagnosis by the ADA and the WHO. The optimal sensitivity for the 1-h, 50-g test was 66.7% (cut-off 137 mg/dl), and for the 2-h, 75-g test (cut-off 119 mg/dl). The best specificity and positive predictive value was for this last test with a cut-off point of 140 mg/dl in the second hour. CONCLUSIONS: The standard 2-h cut-off value of 140 mg/dl for the 75-g test, as now recommended by WHO, was optimal for predicting macrosomia. Based on the sensitivity and specificity for macrosomia, the 1-h, 50-g screening test had an optimal cut-off point of 137 mg/dl (vs. 140 mg/dl recommended by ADA). The 2-h, 75-g OGTT value using a cut-off point of 119 mg/dl had equivalent sensitivity, specificity, and positive predictive value. In contrast, the 100-g OGTT had much lower levels of sensitivity, but higher specificity and higher positive predictive value.     

Comparison of the results between two diagnostic criteria by ADA and WHO among subjects with FPG 5.6-7.8 mmol/l in Kin-Hu and Kin-Chen, Kinmen, 1991-94.

The objective of this study was to compare the results between two diagnostic criteria by ADA (1997) and WHO (1985) among those with fasting plasma glucose (FPG) level 5.6-7.8 mmol/l from a community-based survey in Kin-Hu and Kin-Chen, Kinmen conducted in 1991-94. According to official household registry, 10,797 residents aged over 30 were eligible for screening. 7580 had completed FPG screening and 1855 with FPG 5.6-7.8 mmol/l were invited to receive a 75-g oral glucose tolerance test (OGTT). 78.5% (1456/1855) had completed OGTT. The prevalence of impaired fasting glucose (IFG, by ADA) was 15.7%; the prevalence of impaired glucose tolerance (IGT, by WHO) was 22.7%; the prevalence of undiagnosed diabetes was 7.4% by ADA criteria and 10.9% by WHO criteria. It should be noticed that, among subjects with FPG 5.6-7.8 mmol/l, 50.3% of individuals with undiagnosed diabetes and 67.6% of individuals with IGT by WHO criteria would be missed by ADA criteria. Based on the above findings, the two-step screening strategy using FPG as the first line screening and OGTT for high-risk group (FPG 5.6-7.8 mmol/l) only was recommended in epidemiological study and case finding in consideration of feasibility and validity.     

Prevalence of gestational diabetes mellitus and results of the screening tests at a tertiary referral center: A cross-sectional study

ObjectiveThis study aimed to identify the gestational diabetes mellitus (GDM) prevalence of low risk pregnant population at a tertiary referral center by different approaches.Material and methodsA cross-sectional study using retrospective data between 2007-2017 was conducted. During this period 77227 patients underwent either two step or one step glucose tolerance tests.ResultsThe median age of the study population was 27 (15–49). Fasting plasma glucose (FPG) testing was evaluated in 144,113 women at the initial antenatal care visit which %21 of these were between 92-126 mg/dL. Of these women %1.25 had FPG>126 mg/dL which showed the prevalence of pregestational diabetes in our cohort. During the study period 74412 women underwent 50-g glucose challenge test where %18 were screen positive and % 2.9 was defined as gestational diabetic without need for further testing (>180 mg/dL). The screening positive patients were sent to 100-g oral glucose tolerance test and the prevalence of GDM with two-step screening was 5.5%. A total of 2815 patients were screened by 75-g glucose tolerance test and the prevalence of GDM with one-step screening was 21%. Overall 4684 patients have been diagnosed as gestational diabetes mellitus with the prevalence of 6.07%.ConclusionFasting plasma glucose >92 mg/dL is challenging in our population due to improper fasting. The FPG dependent GDM prevalence is almost four times higher than two-step glucose screening test results (21.8% vs 5.5%). If FPG levels will be used for diagnosing GDM then the values must be checked in a second laboratory analysis.     

Gestational diabetes: fasting capillary glucose as a screening test in a multi‐ethnic,high‐risk population

Aims In populations at high risk of gestational diabetes mellitus (GDM), screening every pregnant woman by an oral glucose tolerance test (OGTT) is very demanding. The aim of this study was to determine the value of the fasting capillary glucose (FCG) as a screening test for GDM. Methods FCG was measured by a plasma‐correlated glucometer in 1465 pregnant women who underwent a one‐step diagnostic 75‐g OGTT for universal screening of GDM. Results One hundred and ninety‐six (13.4%) women had GDM as defined by the criteria of the American Diabetes Association. The area under the receiver operating characteristic curve (AUC) of the FCG was 0.83 (95% confidence interval 0.80–0.86). A FCG threshold of 4.7 mmol/l (at an acceptable sensitivity of 86.0%) independently could rule‐out GDM in 731 (49.9%) women, while the FCG could rule‐in GDM (100% specificity) in 16 (1.1%) additional women; therefore, approximately half of the women would not need to continue with the cumbersome OGTT. Conclusions Screening using a FCG significantly reduces the number of OGTTs needed for the diagnosis of GDM. Wider assessment, particularly in low‐risk populations, would confirm the potential value of the FCG as a screening test for GDM.     

The effect of glucose levels on fetal birth weight: a study of Chinese gravidas in Tianjin, China

The relationship between maternal glucose intolerance and fetal birth weight remains, to a large extent, unknown in Chinese gravidas. From December 1998 to December 1999, 9471[corrected] women in six urban districts of Tianjin, China, underwent an initial screening using a 50-g, 1-h glucose load at 26-30 gestational weeks. Women with a serum glucose reading >or=7.8 mmol/l, were followed up for a 75-g, 2-h glucose tolerance test, which was interpreted using the 1998 World Health Organization's (WHO) criteria for diabetes. A total of 174 women had gestational diabetes mellitus. Complete data was collected in 170 women. Among them, 56 accepted diabetes management including self-home glucose monitoring, diet, and physical activity advice, and others received no treatment. The comparison group was 302 women with normal glucose tolerance (NGT). Glucose levels at the initial screening (partial R(2)=.0343, P<.0001), maternal weight gain during pregnancy (partial R(2)=.0915, P<.0001), and gestational week at delivery (partial R(2)=.0432, P<.0001) were determinants of fetal birth weight, controlling for maternal age, pregravid BMI, maternal stature, and other confounders. Both gestational diabetes mellitus (GDM) status and a positive screening but normal oral glucose tolerance test (OGTT) result were predictors of macrosomia (birth weight >or=4000 g). It concludes that maternal glucose levels correlate with fetal birth weight and a glucose level of 7.8 mmol/l or more at the initial screening is predictive of macrosomia in Chinese gravidas regardless of GDM status.     

Gestational diabetes: utility of fasting plasma glucose as a screening test depends on the diagnostic criteria.

AIMS: To demonstrate the effect of diagnostic criteria, as defined by four international expert panels, on the usefulness of fasting plasma glucose (FPG) as a screening test for gestational diabetes mellitus (GDM). METHODS: We tested 4602 pregnant women using a 75-g oral glucose tolerance test (OGTT) for universal GDM screening. The area under the receiver operating characteristic curve (AUC) was used to determine the FPG performance to detect GDM by the criteria of the American Diabetes Association (ADA), the Australasian Diabetes in Pregnancy Society, the European Association for the Study of Diabetes, and the World Health Organization (WHO). RESULTS: By applying ADA, Australasian, European and WHO criteria, respectively, the FPG: (i) AUC (95% CI) was 0.882 (0.866-0.897), 0.830 (0.809-0.852), 0.808 (0.791-0.825) and 0.690 (0.670-0.710); (ii) independently could 'rule-in' GDM (with 100% specificity) in 74 (10.9%), 620 (53.5%), 252 (45.3%) and 74 (7.6%) women; (iii) independently could 'rule-out' GDM in an additional 2864 (62.2%), 928 (20.2%), 1510 (32.8%) and 1171 (25.4%) women, at FPG thresholds (with 85% sensitivity); (iv) false-positive rate (FPR) was 29.4, 75.5, 63.8 and 71.2%, at these thresholds. CONCLUSIONS: The value of the FPG as a screening test for GDM is highly dependent on the diagnostic criteria. The performance is excellent with the ADA criteria. With the other criteria, the high FPR (poor specificity) would limit its utility as a screening test. Regardless of the criteria used, initial testing by FPG can significantly decrease the number of cumbersome OGTTs needed for the diagnosis of GDM.     

Universal vs. risk factor-based screening for gestational diabetes mellitus: detection rates, gestation at diagnosis and outcome.

AIMS: Gestational diabetes mellitus (GDM) is associated with adverse maternal and fetal outcome. Screening for GDM is therefore recommended but the best screening method remains controversial. This prospective, randomized study compared a risk factor-based screening programme with a universally based one. METHODS: Subjects were randomized at booking to one of two groups: the risk factor group had a 3-h 100-g oral glucose tolerance test (OGTT) at 32 weeks if any risk factor for GDM was present; the universal group had a 50-g glucose challenge test performed and if their plasma glucose at 1 h was > or = 7.8 mmol/l, a formal 3-h 100-g OGTT was then performed. RESULTS: Universal screening detected a prevalence of GDM of 2.7%, significantly more than the 1.45% detected in the risk factor screened group (P<0.03). Universal screening facilitated earlier diagnosis than risk factor screening - mean gestation 30 +/- 2.6 weeks vs. 33 +/- 3.7 weeks (P<0.05). A higher rate of spontaneous vaginal delivery at term, and lower rates of macrosomia, Caesarean section, prematurity, pre-eclampsia and admission to neonatal intensive care unit were observed in the universally screened, early diagnosis group. CONCLUSIONS: Universal screening for GDM is superior to risk factor based screening-detecting more cases, facilitating early diagnosis and is associated with improved pregnancy outcome.