Oral glucose tolerance testing at gestational weeks <= 16 could predict or exclude subsequent gestational diabetes mellitus during the current pregnancy in high risk group
An oral glucose tolerance test with a result that is negative but close to the diagnostic cut-off in early pregnancy was hypothesized to serve as a predictor of subsequent gestational diabetes in a high risk group. The aim of the study was to determine those cut-off values of OGTT at gestational weeks < or =16, which can predict or exclude subsequent onset of GDM in a high risk group. Pregnant women at high risk of gestational diabetes (n = 163) underwent a 2-h, 75-g oral glucose tolerance test at gestational weeks < or =16 were analyzed in this study. In the event of a negative result, subsequent oral glucose tolerance tests were performed at gestational weeks 24-28 and 32-34. The sensitivity, the specificity, the positive and negative predictive values and the Odds ratio of the best cut-off values of fasting and postload glucose levels were calculated. The best cut-off values to exclude subsequent GDM for fasting and postload glucose were 5.0 and 6.2 mmol/l, respectively. In combination, the best cut-off values were 5.3 mmol/l for fasting and 6.8 mmol/l for postload glucose, with negative predictive values of 0.97 and 0.71 and sensitivities of 96.9 and 86.3 at gestational weeks 24-28 and 32-34, respectively. Combination of these cut-off values with obesity proved to be very predictive for gestational diabetes by gestational weeks 32-34, with an Odds ratio of 6.0 [95% confidence interval: 1.7-21.0]. With regard to the very high negative predictive value of the method, pregnant women with glucose levels of < or =5.3 mmol/l at fasting and of < or = 6.8 mmol/l at postload in gestational weeks < or =16 should undergo subsequent oral glucose tolerance testing merely at gestational weeks 32-34. Approximately a quarter (24.5%) of the pregnant women at risk of gestational diabetes satisfied these criteria.
[Show abstract] [Hide abstract] ABSTRACT: 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.0Comments 0Citations
- "In contrast, results from our study shows that among those who returned for a repeat screening (n = 87), 10.3 % developed GDM. Similar findings emphasizing the need for repeat screening have been reported earlier in Hungarian women, where the GDM prevalence was noted to increase with advancing gestation . This therefore highlights the importance of repeat screening among women who screened negative in the first trimester in populations like ours which have a higher risk for GDM. "
[Show abstract] [Hide abstract] ABSTRACT: 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.0Comments 1Citation
- "However, in a study of 163 Hungarian women with various risk factors, such as obesity, family history of type 2 diabetes, and a history of a large infant 4000 g,  the cumulative number of patients with GDM increased with advancing gestation; GDM was diagnosed in eight of the 163 women after 75gGTT at GW < 16, in 32 (BMI, 28.4 ± 7.3) of the remaining 155 with normoglycemia on 75gGTT at GW < 16, but after 75gGTT at GW 24e28, and in 48 (BMI, 27.8 ± 5.9) of the remaining 123 with normoglycemia on the 75gGTT at GW 24e28, but after 75gGTT at GW 32e34.  Although criteria for GDM diagnosis, ethnicity, and BMI of study participants differed between this previous study performed in Hungary  and the present study, these phenomena are well known; GDM is manifested most often in the third trimester, [10,11] as pregnancy fosters a state of insulin resistance with advancing gestation [12e15] as observed in this study; and the 21 women who underwent 75gGTT twice in the first and second trimesters showed significant increases in HOMA-IR and HOMA-b, and a decrease in QUICKI in the absence of significant changes in PG level. However, prepregnancy BMI is a very strong risk factor for GDM amongTable 1 Distribution of first trimester random glucose level in relation to subsequent 75gGTT results and infant birth weight. "
[Show abstract] [Hide abstract] ABSTRACT: 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.0Comments 6Citations
- "There are studies reporting that a decrease in adverse perinatal outcomes might offset the costs of screening . Studies evaluating the first-trimester GDM screening are usually based on only high-risk women282930. Low-risk women represent only 10 % of most populations and identifying these cases may add complexity to the screening process . "