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

Obstetrics and Gynecology Department, University of Szeged, Algyő, Csongrád, Hungary
European Journal of Obstetrics & Gynecology and Reproductive Biology (Impact Factor: 1.7). 07/2005; 121(1):51-5. DOI: 10.1016/j.ejogrb.2004.11.006
Source: PubMed


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.

11 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the glycemic level at the first visit that is likely to predict gestational diabetes mellitus (GDM). Consecutive pregnant women underwent a 75g oral glucose tolerance Test (OGTT) recommended by WHO and diagnosed GDM if 2hr post plasma glucose (PG) value > or = 140 mg/dl. Women with normal OGTT results at the first visit were screened again with an OGTT at the subsequent visits. A total of 4151 pregnant women from different trimesters underwent OGTT. Of them 739 women (17.8%) had GDM. Among the GDM women, 528 (71.4%) were detected at the first visit. On screening during subsequent visits, GDM was diagnosed in the remaining 211(28.6%) women who had normal OGTT in the first visit. We performed the analysis taking the glycemic level in the first visit of 211 pregnant women who manifested GDM in the subsequent visit. During normal pregnancy, 2hr PG level is < 120 mg/dl. Taking this value into consideration among the 211 women who turned to have GDM in the subsequent visits 119 women (56.4%) had 2hrPG > or = 120 mg/dl and the remaining 92(43.6%) had 2hrPG < 120 mg/dl. Pregnant women irrespective of 2 hr PG > or = or < 120 mg/dl at initial visit progressed to GDM in the subsequent visit. No glycemic level in the early weeks of pregnancy predicts GDM and at the same time at no statistically significant glycemic cut-off level could we say that a woman will not develop GDM. Hence rescreening in the subsequent trimester or visits is essential.
    The Journal of the Association of Physicians of India 09/2007; 55:630-2.
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine the relationship between the 75-g oral glucose tolerance test and pregnancy outcome after women's first IVF cycle. Prospective study. Infertility center at a private tertiary hospital in Taiwan. All 280 patients who went through their initial IVF cycle at the hospital between January 2004 and April 2005 were included in the study. Two hundred eighty patients underwent an oral glucose tolerance test before entering an IVF cycle; all pregnancy outcomes and pregnancy complications were recorded. The relationships between glycemic parameters and insulin resistance and IVF pregnancy outcome were determined. Linear regression between birth weight and levels of preconception fasting insulin, 2-hour glucose, and 2-hour insulin was performed. One hundred twenty patients conceived after their initial IVF cycle. Twenty-five of 89 ongoing pregnancies had various complications. The most common pregnancy complication was preterm birth (n = 11). These patients had higher body mass index (23.46 vs. 20.97 kg/m(2)); higher fasting glucose (107.36 vs. 95.14 mg/dL), fasting insulin (10.55 vs. 6.20 microIU/mL), and 2-hour glucose (120.55 vs. 99.97 mg/dL) levels; and higher homeostatic model assessment of insulin resistance (3.43 vs. 1.45) than did patients with full-term pregnancies. Linear regression between birth weight and the fasting glucose level and between birth weight and the homeostatic model assessment of insulin resistance had positive correlations. Before proceeding with IVF, preconception oral glucose tolerance testing is suggested, especially in patients with higher body mass index, to help identify groups who are at high risk for preterm birth.
    Fertility and sterility 12/2007; 90(3):613-8. DOI:10.1016/j.fertnstert.2007.07.1289 · 4.59 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate if any single plasma glucose level from the four values of the normal 100-g oral glucose tolerance test (OGTT) in early pregnancy (< or =20 weeks of gestation) could predict gestational diabetes mellitus (GDM) diagnosed from a second OGTT in late pregnancy (28-32 weeks). Glucose levels of pregnant women at high-risk for GDM, who had had a normal early OGTT, and who underwent the second test in late pregnancy, were studied. Each of the four plasma glucose values of the early OGTT was determined for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The receiver operating characteristic curves of these four OGTT values were then constructed to find the optimal value to predict late-onset GDM. Of 193 pregnant women who had had a normal early OGTT, 154 also had a normal OGTT in late pregnancy while 39 had an abnormal test and were diagnosed with GDM. Among the four glucose values of the early OGTT, the 1-h value yielded the best diagnostic performance to predict late-onset GDM. The sensitivity, specificity, PPV, NPV, and area under the curve achieved from its optimal cutoff level of > or =155 mg/dL (8.6 mmol/L) were 89.7%, 64.3%, 38.9%, 96.1%, and 0.77, respectively. A 1-h glucose value > or =155 mg/dL at the early OGTT yielded the best diagnostic performance. However, the low specificity and PPV rendered it suboptimal to predict late-onset GDM. Nevertheless, a considerable number of high-risk women could avoid the second OGTT in late pregnancy due to its high sensitivity and NPV.
    Journal of Obstetrics and Gynaecology Research 06/2008; 34(3):331-6. DOI:10.1111/j.1447-0756.2007.00693.x · 1.07 Impact Factor
Show more