Gestational diabetes: comparision of the carpenter and the coustan thresholds with the new thresholds of Turkish women and implications of variations in diagnostic criteria

Objective: To find optimal 100-g 3-h oral glucose tolerance test (OGTT) threshold levels for diagnosis of gestational diabetes (GDM) in Turkish pregnant women. Methods: This study was conducted with 808 women screened for GDM between 24–28 weeks of gestation using the 1-h 50-g glucose challenge test (GCT) with a subsequent 3-h 100-g OGTT for confirmation if screen was positive. The glucose values obtained were analysed by both the Carpenter and Coustan (C&C criteria) and National Diabetes Data Group (NDDG) criteria for the diagnosis of GDM and IGT. Optimal OGTT cutoff values for Turkish population were calculated by ROC curve analysis. Results: The new diagnostic criteria, based on the result of the 100-g OGTT obtained from the healthy pregnant women, were 82.5, 171.5, 151.5, and 111.5?mg/dl at 0, 1, 2, and 3?h. The prevalence of GDM was 15.7% by the new criteria, 8.1% by C&C criteria, and 5.6% by the NDDG criteria. According to new criteria, 7.7% of infants of diabetic mothers had macrosomia. This ratio was 2.6% for non diabetic women. Conclusions: Ethnic differences, enviromental factors and nutritional habits may effect development of GDM. Application of some pre-determined nomograms to all races and ethnic groups can lead errors.     

对孕妇行重复性血糖筛查必要性的研究

目的　探讨对孕妇行重复性血糖筛查的必要性及相关因素。方法　 2 0 0 1年 12月 1日至 2 0 0 2年 12月 31日 ,选取自孕早期开始在我院行产前检查并分娩的单胎、初产孕妇 714例 ,在孕中期行口服 5 0 g葡萄糖负荷试验 (GCT) ,对其中的 6 39例在孕晚期行第 2次 5 0 gGCT ;5 7例第 2次直接进行 75g葡萄糖耐量试验 (OGTT)。妊娠期糖尿病的诊断以国内董志光等的标准为准 ,并与美国糖尿病资料组 (NDDG)标准进行比较。同时对发生妊娠期糖尿病相关因素进行分析。结果　 (1)以5 0 gGCT 1h血糖≥ 7 8mmol/L为异常 :第 1次 5 0 gGCT异常 190例 ,异常率为 2 6 6 % ,正常 5 2 4例 (73 4 % ) ;第 2次 5 0 gGCT异常 2 2 5例 ,异常率为 35 2 %。 5 0gGCT异常组孕妇年龄大于正常组(P <0 0 5 ) ,而两组孕妇在家族史及体重指数 (BMI)间比较 ,差异无显著性 (P >0 0 5 )。第 2次 5 0 gGCT异常组的新生儿出生体重及巨大儿例数均比正常组明显增加 (P <0 0 5 )。 (2 )按董志光的标准 ,第 1次 5 0 gGCT筛查出妊娠期糖尿病 2 8例 ,葡萄糖耐量低减 4 0例 ;第 2次 5 0gGCT又新筛查出妊娠期糖尿病 15例 ,葡萄糖耐量低减 2 7例。按NDDG的标准 ,第 1次 5 0 gGCT筛查出妊娠期糖尿病 14例 ,葡萄糖耐量低减 2 4例 ;第 2次 5 0 g     

Abnormal results on a second testing and risk of gestational diabetes in women with normal baseline glucose levels.

OBJECTIVE: To examine the rate of women with normal initial results to glucose tolerance tests who have abnormal results to subsequent testing, and estimate the risk of gestational diabetes mellitus (GDM) in these women. METHODS: Baseline plasma glucose levels were classified as normal if they were less than 120 mg/dL (group 1) or between 120 and 139 mg/dL (group 2) by the 50-g glucose challenge test (GCT); as abnormal if they were found abnormal by the 50-g GCT but normal by the 100-g glucose tolerance test (OGTT) (group 3); and as abnormal if 1 of the four 100-g OGTT values was abnormal (group 4). A second testing session with the 50-g GCT and 100-g OGTT was performed between the 24th and 28th weeks of pregnancy for 900 women at risk whose initial test results were normal. RESULTS: Of the 823 women with normal baseline results who completed the study, 41.4% had abnormal results to the second 50-g GCT, and gestational diabetes mellitus was diagnosed by the 100-g OGTT in 7.0% of these 823 women. Compared with group 1, the women in groups 2, 3, and 4 were at a significantly increased risk of having an abnormal result to the second 50-g GCT. They were also at a significantly increased risk for GDM. The adjusted odds ratios (ORs) were 3.0 for group 2 (95% confidence interval [CI], 1.2-7.2), 4.9 for group 3 (95% CI, 2.2-11.0), and 11.3 for group 4 (95% CI, 3.9-32.6). CONCLUSION: The risk of developing GDM significantly increased with increasing baseline plasma glucose levels by the 50-g GCT.     

全国部分城市妊娠期糖尿病发病情况的调查及适宜诊断标准的探讨

目的 了解我国妊娠期糖代谢异常的发病现状,探讨适合我国卫生经济条件的妊娠期糖代谢异常的诊断标准.方法 前瞻性研究2006年4月1日-9月30日在全国18个城市25家医院行产前检查并进行首次50 g口服葡萄糖负荷试验(GCT)的16 286例孕妇的临床资料,并对GCT检查结果异常(服糖后1 h血糖≥7.8 mmol/L)者行75 g口服葡萄糖耐量试验(OGTT),对结果进行统计学分析.比较采用美国糖尿病学会(ADA)标准和美国国家糖尿病数据组(NDDG)标准诊断妊娠期糖代谢异常的发生率,以及妊娠期糖尿病(GDM)、妊娠期糖耐量受损(GIGT)及糖代谢正常孕妇OGTr各时间点(空腹、1 h、2 h、3 h)血糖的平均值.结果 按NDDG标准诊断,GDM及GIGT的发生率分别为2.763%(450/16 286)和3.862%(629/16 286);按ADA标准诊断则分别为5.078%(827/16 286)和5.268%(858/16 286);符合ADA标准中2项及以上异常者为841例,符合NDDG标准中1项及以上异常者为1034例,同时符合以上两个条件者为792例,分别占两者的94.2%(792/841)和76.6%(792/1034).采用ADA标准诊断的糖代谢正常者OGTF各时间点(空腹、1 h、2 h、3 h)血糖值的95%可信区间上限依次为5.3、10.4、8.7、7.7 mmol/L,与NDDG标准(分别为5.4、10.8、9.1、7.8 mmol/L)基本一致.结论 目前,妊娠期糖代谢异常发生率呈现增加趋势.ADA标准适合我国GDM的诊断,据我国目前的卫生经济情况,对NDDG标准中l项及以上异常者或对ADA标准中2项及以上异常者进行干预都是合理的.     

The predictive value of the 1-h 50-g glucose screen for diagnosing gestational diabetes mellitus in a high-risk population

Objective: To determine a value, for a gestational diabetes mellitus (GDM) screening test, above which the glucose tolerance test is obviated.

Methods: A database search of patients delivered at the Medical College of Virginia Hospital (MCV) between April 1991 and April 2002 was undertaken. Subjects were screened using standard methodology: blood glucose level 1?h after a 50-g oral glucose load (1OGT). Subjects with values meeting/exceeding 140?mg/dl underwent 3-h 100-g oral glucose tolerance tests (3OGTT). GDM was diagnosed using criteria of the National Diabetes Data Group (NDDG), with Carpenter–Coustan (CC) criteria for comparison. Receiver–operator characteristic (ROC) curves were generated; areas under the curve (AUC) were calculated.

Results: 1OGT results were available for 16?898 subjects; 2770 (16.4%) had values meeting/exceeding 140?mg/dl. The NDDG and CC criteria were applied to 1972 subjects with both 1OGT and 3OGTT results available: 419 (21%) and 614 (31%) subjects had GDM, respectively. Positive predictive values for results ??180?mg/dl and values at 20?mg/dl increments up to 260?mg/dl were: 36, 47, 55, 57 and 63% (NDDG) and 45, 54, 62, 61 and 66% (CC). AUC for NDDG?=?0.68; AUC for CC?=?0.64.

Conclusions: GDM cannot be diagnosed with the 1OGT; predictive values are low. A cut-off of 200?mg/dl predicts only?47–54% of GDM cases correctly, and may lead to over-diagnosis. It is inappropriate for GDM to be diagnosed based on the 1OGT.     

Gestational diabetes mellitus in Chinese women.

OBJECTIVE: To determine whether foreign diagnostic criteria for the diagnosis of gestational diabetes mellitus (GDM) are suitable for Chinese pregnant women. METHODS: The study participants were 340 pregnant women receiving obstetric care at the Shanghai Jiaotong University-Affiliated Sixth People's Hospital in Shanghai, China. The normal-pregnancy group comprised 190 women with no risk factor for GDM and the high-risk pregnancy group comprised 150 women who had at least one high-risk factor for GDM. All women took the diagnostic 100-g, 3-h oral glucose tolerance test (100-g 3-h OGTT) between 24 and 28 weeks of pregnancy. The results of the 100-g 3-h OGTT were classified according to three different sets of diagnostic criteria: (1) new, "Chinese" diagnostic criteria based on the results from the 100-g 3-h OGTT performed in the 190 healthy participating women; (2) the Carpenter and Coustan criteria; and (3) the National Diabetes Data Group (NDDG) criteria. Venous plasma glucose (VPG) was measured by the glucose oxidase method. A consistency check was used for analysis. Obstetric and neonatal outcomes were recorded. RESULTS: With 97.5% as the statistical cutoff value for the 100-g 3-h OGTT, the new diagnostic criteria for this study, based on data obtained from the 100-g 3-h OGTT performed on the 190 participating healthy pregnant women, were 5.2, 10.3, 8.9, and 7.7 mmol/L at 0, 60, 120, and 180 min. The e value was 0.83 for the new criteria vs. the Carpenter and Coustan criteria (P<0.001) and 0.70 for the new criteria vs. the NDDG criteria (P<0.001). In women with GDM and gestational-impaired glucose tolerance (GIGT), the incidence rates of macrosomia by the new criteria and the Carpenter and Coustan criteria were similar, but higher than the rates calculated with the NDDG criteria (P<0.05). CONCLUSION: With venous plasma glucose level measured by the glucose oxidase method, the Carpenter and Coustan criteria are applicable to Chinese pregnant women for diagnosis of GDM.     

Are patients with positive screening but negative diagnostic test for gestational diabetes under risk for adverse pregnancy outcome?

OBJECTIVE: Our aim was to determine the obstetrics outcomes of patients with positive 1-h glucose challenge test (GCT), but negative diagnostic test for gestational diabetes. METHODS: Pregnancy records of 409 pregnants were reviewed. Patients were screened for gestational diabetes mellitus (GDM) with one-hour 50 g glucose challenge test (GCT) at 24-28 weeks of gestation. Patients with glucose challenge tests values > or = 130 mg/dL were refered for the 3 h, 100-g oral glucose tolerance test (OGTT). Positive GCT but negative for OGTT group (Group A) were compared retrospectively with the group of negative GCT (Group B) for obstetrics outcomes. RESULT: GDM and impared glucose tolerance (IGT) were diagnosed in 33 (7.6%) and 46 (10.5%) patients, respectively. We identified 141 (34.4%) patients with positive GCT but negative for OGTT (Group A) and 189 (46.2%) patients with negative GCT (Group B). Gestational weight gain, polyhydramnios, family history of diabetes mellitus were significantly higher in group A than group B (P < 0.05). Prevalance of preterm labor, hypertension, cesarean delivery, mean birthweight, proportion of babies admitted to neonatal intensive care unit were similar in both groups. CONCLUSION: There are some differences for pregnancy outcomes between pregnants with positive GCT but negative for OGTT and negative GCT. These patients should be followed up carefully during the antepartum and intrapartum period.     

Is abnormal 50-g glucose-challenge testing an independent predictor of adverse pregnancy outcome?

Objective: To determine whether an abnormal 50-g glucose-challenge test (GCT) is independently associated with adverse pregnancy outcome. Methods: A retrospective study of women with abnormal GCT (>140?mg/dL) but normal subsequent 100-g oral glucose-tolerance test (OGTT). Pregnancy outcome was compared with that of women with normal GCT (<140?mg/dL). Results: Of the 79,153 women delivered during the study period, the results of the GCT were available for 14,268. Of these, 809 (5.7%) had an abnormal GCT and normal OGTT and were eligible for the study group. An abnormal GCT was independently associated with an increased risk for macrosomia (odds ratio [OR] = 2.0, 95% CI: 1.5–2.7), large for gestational age (OR = 1.6, 95% CI: 1.3–2.0), cesarean section (OR = 1.3, 95% CI: 1.1–1.6), respiratory morbidity (OR = 1.6, 95% CI: 1.1–2.7) and neonatal hypoglycemia (OR = 1.8, 95% CI: 1.1–3.2). In contrast, an abnormal GCT was associated with decreased risk for preterm delivery at less than 37 weeks (OR = 0.7, 95% CI: 0.5–0.9) and 34 weeks (OR = 0.3, 95% CI: 0.1–0.6). The association between abnormal GCT and adverse pregnancy outcome was unrelated to the degree of GCT abnormality except for cases in which the GCT was extremely high (≥180?mg/dL). Conclusion: Women with abnormal-GCT result are at increased risk for adverse pregnancy outcome even in the presence of a normal subsequent OGTT.     

Does maternal hypoglycemia during screening glucose assessment identify a pregnancy at-risk for adverse perinatal outcome?

OBJECTIVE: To determine the perinatal outcome in pregnancies with maternal hypoglycemia following a second trimester oral glucose challenge test (GCT). STUDY DESIGN: Retrospective case-control study of pregnancies undergoing a second trimester 1-hour oral glucose challenge test (GCT). Hypoglycemic pregnancies (<88 mg/dl) were matched with pregnancies with 1-hour glucoses of >88 mg/dl. Antepartum, intrapartum, and neonatal outcomes were assessed. RESULTS: Over 29 months, 334 hypoglycemic singleton pregnancies were matched with 334 controls. A greater number of special/neonatal intensive care unit (SCN/NICU) admissions occurred in the hypoglycemic group (48/334 (14.4%) vs 29/334 (8.7%) in the control group) (p=0.02). The SCN/NICU admission rate remained after controlling for maternal hypertension, smoking, and preterm birth (p=0.037). The development of pregnancy-induced hypertension in women with hypoglycemia 24/334 (7.2%) compared with euglycemic women 13/334 (3.9%, p<0.06) was not significant. CONCLUSION: Admission to SCN/NICU is increased in pregnant women with hypoglycemia following a GCT.     

Obstetric outcomes with a false-positive one-hour glucose challenge test by the Carpenter-Coustan criteria.

OBJECTIVE: Pregnancies complicated by a false-positive one-hour glucose challenge test (GCT), as determined by the National Diabetes Data Group (NDDG) criteria, have higher rates of adverse maternal and neonatal outcomes. This study was conducted to determine if pregnancies complicated by a false-positive GCT, as determined by the Carpenter-Coustan (CC) criteria, also have higher rates of adverse maternal and neonatal outcomes. STUDY DESIGN: In this retrospective case-control study, we compared 165 patients with a false-positive GCT, as determined by the Carpenter-Coustan criteria, to a cohort of 165 pregnant controls with a normal screening GCT. Multiple variables for maternal and neonatal outcomes were compared between the two groups. RESULTS: The racial distribution and gestational age of delivery were similar in both groups. The study group had a higher one-hour GCT (148.2 mg/dl vs. 95.3 mg/dl, p < 0.001), was older (27.4 yrs vs. 23.8 years, p < 0.001), was more likely to be multiparous (71.5% vs. 58.2%, p = 0.011), and had a higher BMI (26.7 kg/m2 vs. 24.6 kg/m2, p = 0.002). There were no differences between the two groups in mode of delivery, birth weight, rates of macrosomia, shoulder dystocia, antenatal death and maternal laceration. There were also no differences between the two groups in rates of preeclampsia, chorioamnionitis, endometritis, ICN admission, neonatal hypoglycemia, Erb's palsy, clavicular fracture, neonatal sepsis, neonatal death or use of phototherapy. CONCLUSION: Women with a false-positive one-hour GCT by the Carpenter-Coustan criteria do not have higher rates of adverse perinatal outcomes. Using the Carpenter-Coustan criteria to diagnose GDM appears to be superior to NDDG criteria in terms of avoiding adverse maternal and neonatal outcomes.     

The predictive value of the 1-h 50-g glucose screen for diagnosing gestational diabetes mellitus in a high-risk population.

OBJECTIVE: To determine a value, for a gestational diabetes mellitus (GDM) screening test, above which the glucose tolerance test is obviated. METHODS: A database search of patients delivered at the Medical College of Virginia Hospital (MCV) between April 1991 and April 2002 was undertaken. Subjects were screened using standard methodology: blood glucose level 1 h after a 50-g oral glucose load (1OGT). Subjects with values meeting/exceeding 140 mg/dl underwent 3-h 100-g oral glucose tolerance tests (3OGTT). GDM was diagnosed using criteria of the National Diabetes Data Group (NDDG), with Carpenter-Coustan (CC) criteria for comparison. Receiver-operator characteristic (ROC) curves were generated; areas under the curve (AUC) were calculated. RESULTS: 1OGT results were available for 16898 subjects; 2770 (16.4%) had values meeting/exceeding 140 mg/dl. The NDDG and CC criteria were applied to 1972 subjects with both 1OGT and 3OGTT results available: 419 (21%) and 614 (31%) subjects had GDM, respectively. Positive predictive values for results > or =180 mg/dl and values at 20 mg/dl increments up to 260 mg/dl were: 36, 47, 55, 57 and 63% (NDDG) and 45, 54, 62, 61 and 66% (CC). AUC for NDDG=0.68; AUC for CC=0.64. CONCLUSIONS: GDM cannot be diagnosed with the 1OGT; predictive values are low. A cut-off of 200 mg/dl predicts only 47-54% of GDM cases correctly, and may lead to over-diagnosis. It is inappropriate for GDM to be diagnosed based on the 1OGT.     

Is treatment needed for mild impairment of glucose tolerance in pregnancy? A randomized controlled trial

Summary. The study was designed to identify those pregnant women who are diagnosed as having gestational diabetes by National Diabetes Data Group (NDDG) criteria, but normal glucose tolerance (NGT) or impaired glucose tolerance (IGT) by the World Health Organization (WHO) criteria, and to test whether treatment changed the perinatal outcome in those with NGT and IGT. The 216 women with an abnormal 100 g oral glucose tolerance test (OGTT) using NDDG criteria were subjected to a 75 g OGTT. Using the WHO criteria, 111 women (51%) had NGT, 98 (45%) had IGT and 7 (3%) had frank diabetes mellitus. Those with NGT and IGT were randomized into control and treatment groups. The perinatal outcome in these two groups was comparable whether the NGT and IGT groups were analysed together or separately except, that in those who were treated for IGT, smaller babies were born one week earlier than in the control group (3407 g vs 3110g, P<0·01). This suggests that the WHO criteria can safely replace the 100 g OGTT with substantial savings in manpower, money and patients' time.     

Intrapartum screen for diabetes in patients without prenatal care: Use of labor admission serum glucose

Objective: For patients presenting in labor with no prenatal care, a rapid screening test for gestational diabetes would potentially aid in decisions for tocolysis (e.g., preterm patients) and mode of delivery (e.g., large for gestational age). We sought to determine whether a labor admission serum glucose is of predictive value in the diagnosis of gestational diabetes.

Methods: We obtained labor admission glucose values for laboring patients and compared these with 1-h (50-g) postglucola (1° PG) screens obtained at 24 to 32 weeks' gestation. Diabetics being treated with insulin were excluded from the study. Labor admission serum glucose values were compared to 1° PG values by linear regression. Sensitivity and specificity of admission glucose for identification of a positive 1° PG (140 mg/dl) were evaluated by a receiver operator curve (ROC).

Results: A total of 98 patients with both 1° PG screens and labor admission glucose were identified. Linear regression showed no significant correlation of labor admission glucose and 1° PG values (r = 0.13; P = 0.9). The ROC failed to demonstrate an optimal admission random glucose cutoff value for diagnosis of diabetes.

Conclusions: In laboring patients without insulin-requiring diabetes, labor admission glucose does not predict an abnormal 1° PG and thus does not aid in labor management of patients with suboptimal prenatal care.     

Is treatment needed for mild impairment of glucose tolerance in pregnancy? A randomized controlled trial

The study was designed to identify those pregnant women who are diagnosed as having gestational diabetes by National Diabetes Data Group (NDDG) criteria, but normal glucose tolerance (NGT) or impaired glucose tolerance (IGT) by the World Health Organization (WHO) criteria, and to test whether treatment changed the perinatal outcome in those with NGT and IGT. The 216 women with an abnormal 100 g oral glucose tolerance test (OGTT) using NDDG criteria were subjected to a 75 g OGTT. Using the WHO criteria, 111 women (51%) had NGT, 98 (45%) had IGT and 7 (3%) had frank diabetes mellitus. Those with NGT and IGT were randomized into control and treatment groups. The perinatal outcome in these two groups was comparable whether the NGT and IGT groups were analysed together or separately except, that in those who were treated for IGT, smaller babies were born one week earlier than in the control group (3407 g vs 3110 g, P less than 0.01). This suggests that the WHO criteria can safely replace the 100 g OGTT with substantial savings in manpower, money and patients' time.     

Screening for gestational diabetes at antenatal booking in a Malaysian university hospital: the role of risk factors and threshold value for the 50-g glucose challenge test

BACKGROUND: The best method of screening for gestational diabetes (GDM) remains unsettled. The 50-g glucose challenge test (GCT) is used in a two-stage screening process but its best threshold value can vary according to population. AIMS: To evaluate the role of risk factors in conjunction with GCT and to determine an appropriate threshold for the one-hour venous plasma glucose with the GCT. METHOD: In a prospective study, 1600 women at antenatal booking without a history of diabetes mellitus or GDM filled a form on risk factors before GCT. Women who had GCT >or= 7.2 mmol/L underwent the 75-g oral glucose tolerance test (OGTT). GDM was diagnosed according to WHO (1999) criteria. RESULT: Thirty-five per cent had GCT >or= 7.2 mmol/L, 32.6% underwent OGTT and 34.5% of OGTT confirmed GDM. The GDM rate in our population was at least 11.4%. Examination of the receiver operator characteristic curve suggested that the best threshold value for the GCT in our population was >or= 7.6 mmol/L. Multivariable logistic regression demonstrated that only GCT >or= 7.6 mmol/L was an independent predictor for GDM (adjusted odds ratio 3.7: P < 0.001). After GCT, maternal age and anthropometry, OGTT during the third trimester, family history, obstetric history and glycosuria were not independent predictors of GDM. CONCLUSIONS: Risk factors were not independent predictors of GDM in women with GCT >or= 7.2 mmol/L. GCT threshold value >or= 7.6 mmol is appropriate for the Malaysian population at high risk of GDM.     

A population-based risk factor scoring will decrease unnecessary testing for the diagnosis of gestational diabetes mellitus

BACKGROUND: To determine the effectiveness of a population-based risk factor scoring to decrease unnecessary testing for the diagnosis of gestational diabetes mellitus (GDM). METHODS: We formed a risk factor scoring over five, which questions maternal age, body mass index and first-degree relatives with a diagnosis of diabetes mellitus, a prior macrosomic fetus and adverse outcome during the previous pregnancies. All participants underwent a 50-g glucose challenge test (GCT) followed by a 100-g oral glucose tolerence test (OGTT). We opened the 50-g GCT envelope if the participant had a risk score > or = 1 and opened the 100-g OGTT envelope if the 50-g GCT value was > or = 7.2 mmol/l. After all patients delivered we also built other strategies and tested their detection rates. RESULTS: Fourteen patients (3.3%) were diagnosed as having gestational diabetes mellitus via a 100-g OGTT. None of the patients with a score of zero had gestational diabetes mellitus. Logistic regression analysis revealed that an increase in the score by one caused a three times increase in gestational diabetes mellitus risk (OR = 3, CI = 1.9-5). Compared with the universal screening, our strategy to screen if the risk score was > or = 1, followed by a 50-g GCT with a 7.2-mmol/l cut-off value, decreased the number of women to be screened by 30% and diagnosed all cases with GDM. Screening the patients with a score > or = 2 would have decreased the number of women to be screened by 63%, still diagnosing 85% of cases with GDM. Also, risk factor-based screening strategies cause a 50% and 53% reduction in the number of OGTT applied, respectively. CONCLUSION: A well integrated, population-based scoring will decrease the number of unnecessary testing but still diagnose 85-100% of GDM cases.     

Gestational diabetes mellitus and lesser degrees of pregnancy hyperglycemia: association with increased risk of spontaneous preterm birth

OBJECTIVE: To investigate whether different degrees of maternal glucose intolerance are associated with the risk of spontaneous preterm birth. METHODS: We performed a cohort study of 46,230 pregnancies screened by a 50-g, 1-hour oral glucose tolerance test between 24 and 28 gestation weeks at the Northern California Kaiser Permanente Medical Care Program. Spontaneous preterm birth was defined as an infant born at less than 37 gestation weeks with at least one of the following: spontaneous labor, preterm premature rupture of membranes, or incompetent cervix. Glucose tolerance status was categorized as normal screening (1-hour plasma glucose less than 140 mg/dL), abnormal screening (1-hour plasma glucose of at least 140 mg/dL with a normal diagnostic 100-g, 3-hour oral glucose tolerance test result), Carpenter-Coustan (plasma glucose measurements during the diagnostic oral glucose tolerance test met the thresholds but were lower than the National Diabetes Data Group thresholds), and gestational diabetes mellitus (GDM) by the National Diabetes Data Group criteria. RESULTS: One thousand nine hundred fifty-six spontaneous preterm births occurred. Age-adjusted incidences of spontaneous preterm birth were 4.0% in normal screening, 5.0% in abnormal screening, 6.7% in Carpenter-Coustan, and 6.7% in GDM. In a logistic regression model adjusted for age, race-ethnicity, preeclampsia-eclampsia-pregnancy-induced hypertension, chronic hypertension, polyhydramnios, and birth weight for gestational age, pregnancies with abnormal screening, Carpenter-Coustan, and GDM had a significantly higher risk of spontaneous preterm birth than pregnancies with normal screening (relative risk [95% confidence interval]: 1.23 [1.08, 1.41], 1.53 [1.16, 2.03], and 1.42 [1.15-1.77], respectively). CONCLUSION: The risk of spontaneous preterm birth increased with increasing levels of pregnancy glycemia. This association was independent of perinatal complications that could have triggered early delivery.     

妊娠期糖尿病诊断标准的探讨

目的　探讨妊娠期糖尿病 ( GDM)的诊断标准。　方法　对 1 578例孕妇进行血糖筛查试验 ,阳性者进行葡萄糖耐量试验 ( OGTT)。按照世界卫生组织 ( WHO)、美国糖尿病资料组 ( NDDG)和国内 (董志光等 )三种诊断标准对孕妇进行诊断并分组 ,随机选择糖筛查试验阴性孕妇 1 0 0例作为对照组 ,对四组母儿妊娠结局进行比较。　结果　血糖筛查试验阳性 2 76例 ,OGTT试验达到 WHO、NDDG、国内标准者分别为 3 3、60、68例 ,检出率分别为 2 .1 % ( 3 3 / 1 578) ,3 .8% ( 60 / 1 578) ,和 4 .3 %( 68/ 1 578)。各 GDM组间比较 ,产母重度妊高征、羊水过多、羊水过少、巨大儿的发生率和剖宫产率均无显著性差异 ( P>0 .0 5) ,而与对照组相比 ,存在显著性差异 ( P<0 .0 5)。　结论　及时诊断并积极处理 GDM对获得良好的妊娠结局是极为必要的。 WHO标准过于严格 ;NDDG标准可以应用 ,但有漏诊的可能 ,国内标准有待大样本证实。     

The association between glucose challenge test, obesity and pregnancy outcome in 6390 non-diabetic women.

OBJECTIVE: To evaluate the association between obesity, glucose challenge test (GCT) and pregnancy outcome. METHODS: A prospective cohort study of 6854 consecutive gravid patients screened for gestational diabetes (GDM) using 50-gram GCT, at 24-28 weeks' gestation was performed. A screening value 130 mg/dl was followed by 100 gr oral GTT. Patients who were diagnosed with GDM were excluded. For purpose of analysis patients were categorized by prepregnancy BMI and by different GCT thresholds. Maternal outcome was defined by rate of preeclampsia, gestational age at delivery, cesarean section (CS) rate and the need for labor induction. Neonatal outcome was defined by fetal size (macrosomia/LGA), arterial cord pH, respiratory complications and neonatal intensive care unit (NICU) admission. RESULTS: Overall, a positive GCT result (GCT > or = 130 mg/dl) was identified in 2541/6854 (37%) women. GDM was further diagnosed in 464/6854 (6.8%) of subjects. In both groups of screening results ( > 130 mg/dl and < 130 mg/dl), the obese women were significantly older, gained more weight during pregnancy and had a lower rate of nulliparity in comparison to the non obese women. The obese women had higher rates of macrosomia, LGA and induction of labor. No difference was found in mean birth weight, the total rate of cesarean section, preterm delivery, 5 minute Apgar score < or = 7, mean arterial cord pH, NICU admission and a need for respiratory support in comparison to non obese women in both groups of screening results. A gradual increase in the rate of macrosomia, LGA and cesarean section was identified in both obese and non-obese women in relation to increasing GCT severity categories. CONCLUSION: Fetal size and cesarean section rate are associated with the degree of carbohydrate intolerance (screening results). Furthermore, obesity remains the main contributor impacting fetal size.     

A comparison between a 75-g and 100-g oral glucose tolerance test in pregnant women.

OBJECTIVES: To test the validity of a 75-g, 2-h oral glucose tolerance test (OGTT) for diagnosing gestational diabetes mellitus (GDM) using the criteria and reference values suggested by the American Diabetes Association for the 100-g, 3-h OGTT. METHODS: The results of a 75-g, 2-h OGTT were compared with those of a 100-g, 3-h OGTT in 42 pregnant women. The women's mean+/-S.D. age and gestational age were 33.6+/-5.4 years and 28.2+/-4.2 weeks, respectively. Each subject was randomly scheduled within 1 week for both the 75-g and 100-g OGTTs. RESULTS: The mean plasma glucose concentrations at 1, 2, and 3 h during the 100-g OGTT were significantly higher than those during the 75-g OGTT. Using the Carpenter and Coustan criteria, the prevalence of GDM was 21.4% when using the 100-g, 3-h OGTT, whereas it was found to be at only 7.1% when using the 75-g, 2-h OGTT. CONCLUSIONS: Plasma glucose responses during the 75-g OGTT were found to be lower than those during the 100-g OGTT. When using the same diagnostic criteria, the prevalence of GDM was also found lower using the 75-g glucose load. It would therefore not be appropriate to use the 75-g OGTT for diagnosing GDM using the criteria and reference values of the 100-g OGTT. To give a comparable prevalence of GDM, the threshold of abnormal plasma glucose levels of the 75-g OGTT would need to be lower than that of the 100-g OGTT.