Gestational diabetes. Is a 50-g screening result > or = 200 mg/dL diagnostic?

OBJECTIVE: To evaluate the diagnosis of gestational diabetes based on a 50-g, one-hour glucose screening test result > or = 200 mg/dL. STUDY DESIGN: Retrospective ascertainment of pregnant women who had a 50-g, one-hour glucose screening test result > or = 200 mg/dL was performed among prenatal care registrants. The diagnosis of gestational diabetes was determined by 100-g, three-hour oral glucose tolerance test (GTT) results and/or repeated fasting serum glucose measures. RESULTS: In 1995, 69 women were referred to the gestational diabetes clinic with a 50-g result > or = 200 mg/dL. Four women could not be classified, two had pregestational glucose intolerance and four charts were unavailable. Of the remaining 59 women, 11 (19%) had normal three-hour GTTs, and 48 (81%) were diagnosed with gestational diabetes (35 [59%], A1; 13 [22%], A2). There was one large-for-gestational-age (LGA) infant born in the nondiabetic group (9%), 13 LGA infants born in the A1 group (37%) and 6 LGA infants born to the A2 diabetics (46%). The relationship between maternal diagnosis and LGA outcome was statistically significant. CONCLUSION: A 50-g screening test result > or = 200 mg/dL is not diagnostic of gestational diabetes. Nearly one of five such women had a normal three-hour oral GTT. Overdiagnosis of gestational diabetes may lead to unnecessary pregnancy surveillance and intervention.     

A prospective controlled study of neonatal morbidities in infants born at 36 weeks or more gestation to Women with diet-controlled gestational diabetes (GDM-class Al).

OBJECTIVE: Infants of gestational diabetes mellitus (GDM)-A1 women are unlikely to experience the marked excursion in maternal glucose levels that may characterize insulin-requiring GDM (class-A2) or insulin-dependent diabetes (IDDM). However, infants born to GDM-A1 women are traditionally managed like infants born to GDM-A2 or IDDM women. AIMS: To examine monitoring protocols for infants of GDM-A1 women, and to examine the efficacy of early and frequent feedings to prevent and to treat hypoglycemia. METHODS: A total of 92 of 101 infants born to GDM-A1 women (diabetic group) and 68 of 83 infants born to nondiabetic women (control group) at > or=36 weeks of gestation were prospectively monitored for the development of hypoglycemia and other morbidities. Blood glucose screening was performed in the diabetic group every 30-60 minutes three times, starting soon after birth and then at 3-hour intervals for 24 hours. Liberal feedings were started shortly after birth and provided every 3 hours for at least 24 hours. All women with GDM-A1 had an HbA1c measured before delivery. RESULTS: Both the diabetic and control groups had similar demographics, including LGA incidence. Blood glucose readings before feedings were low (<40 mg/dl) in 24 of 92 infants (26.1%) from the diabetic group and in 20 of 68 control infants (29%). After the start of oral feedings, all but four diabetic and three control infants had subsequent glucose readings > or =40 mg/dl. No infant had symptoms of hypoglycemia and none from the diabetic group had birth trauma, hypoxic-ischemic encephalopathy, polycythemia, hypocalcemia, or hypomagnesemia. Hypoglycemic episodes in the infants from the diabetic group could be managed with oral feedings alone. Birth weight, gestational age, sex, Apgar scores, and maternal HbA1c levels could not predict low glucose readings on initial screening in infants from the diabetic group. CONCLUSION: The incidence of hypoglycemia in infants born to GDM-A1 women at > or =36 weeks of gestation is similar to control infants born to nondiabetic women. Low blood glucose levels during the first few hours of life can be prevented or treated with early and frequent oral feeding.     

Impaired glucose tolerance associated with adverse pregnancy outcome: a population-based study in southern Sweden

OBJECTIVE: We conducted a population-based study of maternal and neonatal characteristics and delivery complications in relation to the outcome of a 75-g, 2-hour oral glucose tolerance test at 25 to 30 weeks' gestation. STUDY DESIGN: An oral glucose tolerance test was offered to pregnant women in a geographically defined population. Pregnancy outcome was analyzed according to the test result. RESULTS: Among women delivered at Lund Hospital, we identified 4526 women with an oral glucose tolerance value of <7.8 mmol/L (<140 mg/dL), 131 women with a value of 7.8 to 8.9 mmol/L (140-162 mg/dL), and 116 women with gestational diabetes (> or =9.0 mmol/L [> or =162 mg/dL]). A further 28 cases of gestational diabetes were identified, giving a prevalence of 1.2%. An increased rate of cesarean delivery and infant macrosomia was observed in the group with a glucose tolerance value of 7.8 to 8.9 mmol/L (140-162 mg/dL) and in the gestational diabetes group. Advanced maternal age and high body mass index were risk factors for increased oral glucose tolerance values in 12,657 screened women in the area. CONCLUSION: The study stresses the significance of moderately increased oral glucose tolerance values.     

Low values on 50 gram glucose challenge test or oral 100 gram glucose tolerance test are associated with good perinatal outcome.

We set out to reevaluate the hypothesis that high normal (negative) results of 50 g oral glucose challenge test or high normal glucose level on 100 g oral glucose tolerance test are associated with complications of pregnancy and delivery. This was a prospective study involving 735 nondiabetic women. The first group (n=352) was made up of pregnant women with normal 50 g oral glucose challenge test without previous history of diabetes mellitus or gestational diabetes. The second group (n=383) was made up of pregnant women without previous history of diabetes mellitus or gestational diabetes with an abnormal 50 g oral glucose challenge test and with normal 100 g oral glucose tolerance test and not more than one previous delivery. In nondiabetic women, we demonstrated a positive correlation between high normal 50 g glucose challenge test values and the incidence of preeclampsia, caesarean section rate, macrosomia, neonatal hyperlipidaemia and minor congenital abnormalities. We failed to confirm any relationship to any pregnancy complication in pregnant women with 2-hour glucose levels in the range 6.7-9.1 mmol/l on the 100 g oral glucose tolerance test. We have demonstrated a positive relationship between the incidence of premature rupture of membranes and 1-hour glucose level, caesarean section rate and maternal 1-hour glucose level or 1-hour glucose level minus fasting glucose level of 4.2 mmol/l, instrumental delivery rate and maternal 3-hour glucose level, incidence of neonatal macrosomia and 1-hour glucose level, and incidence of neonatal hyperlipidaemia and at least one high but normal glucose level on the 100 g oral glucose tolerance test. With regard to pregnancy and delivery complications there were no significant difference if the high normal value is on the 50 g glucose challenge test or on the 100 g oral glucose tolerance test. It is concluded that one high normal 100 g oral glucose tolerance test or high normal 50 g glucose challenge test are associated with adverse pregnancy and delivery outcome. Nondiabetic women with 50 g glucose challenge test value of 6.1 mmol/l and/or 100 g oral glucose tolerance test values of 5 mmol/l have a favourable pregnancy and delivery outcome.     

Effect of fetal hyperinsulinism on oral glucose tolerance test results in patients with gestational diabetes mellitus

OBJECTIVE: This study was undertaken to evaluate the impact of the fetoplacental glucose steal phenomenon on the results of oral glucose tolerance testing in pregnancies complicated by gestational diabetes mellitus with fetal hyperinsulinism. STUDY DESIGN: This was an analysis of the cases of 34 patients with two consecutive abnormal oral glucose tolerance test results and amniotic fluid insulin measurement before institution of insulin therapy. Patients were divided into groups on the basis of normal versus elevated amniotic fluid insulin concentrations. RESULTS: Oral glucose tolerance tests were done at a mean (+/-SD) of 24.9 +/- 5.7 and 30.7 +/- 3.2 weeks' gestation, and amniotic fluid insulin measurements were done at 31.1 +/- 3.2 weeks' gestation. In 13 women with gestational diabetes mellitus with normal amniotic fluid insulin concentration, maternal postload blood glucose levels at 1 hour increased by 12 mg/dL (168 vs 180 mg/dL; 9.3 vs 10.0 mmol/L; P = .0006) during the course of 6 weeks. In contrast, in 21 women with gestational diabetes mellitus with elevated amniotic fluid insulin levels (>7 microU/mL; >42 pmol/L), 1-hour postload blood glucose levels decreased by 22 mg/dL (201 vs 179 mg/dL; 11.2 vs 9.9 mmol/L; P = .002) during the same period. The higher the amniotic fluid insulin level, the larger the decrease (R = 0.504; P =.02). Although low amniotic fluid insulin levels were correlated significantly with 1-hour glucose levels of the first and second oral glucose tolerance tests, high insulin levels were no longer correlated with the second oral glucose tolerance test. CONCLUSION: Exaggerated fetal glucose siphoning may provide misleading oral glucose tolerance test results in pregnancies complicated by fetal hyperinsulinism by blunting maternal postload glucose peaks. Consequently, oral glucose tolerance test results in a pregnancy complicated by gestational diabetes mellitus with a fetus that already has hyperinsulinemia may erroneously be considered normal.     

Effect of varying degrees of "normal" glucose metabolism on maternal and perinatal outcome

Prior studies concerning effects of varying degrees of normal glucose metabolism on pregnancy have reported an increase in the incidence of a variety of pregnancy complications in women with normal oral glucose tolerance test results as the glucose concentration after a standardized meal rose. However, these investigations have neglected to include a control group of women with gestational diabetes for comparison. We theorized that if the adverse outcomes noted were indeed a reflection of glucose concentration, women with gestational diabetes should have an even higher incidence of these complications. Mother and infant charts of 312 consecutive women undergoing an oral glucose tolerance test were reviewed. A glucose challenge test preceded the oral glucose tolerance test in 310. The glucose challenge test value was less than 140 mg/dl in 64 and greater than or equal to 140 mg/dl in 246. There were 63 abnormal oral glucose tolerance test results (2.7% of the population studied). Among all patients, the relationship between glucose challenge test and oral glucose tolerance test values followed a gradient with a progressive rise in mean oral glucose tolerance test values when the glucose challenge test result was greater than or equal to 160 mg/dl. However, the incidence of an abnormal oral glucose tolerance test result did not rise significantly until the glucose challenge test result exceeded 180 mg/dl. A wide variety of outcome parameters were studied; none were related to the glucose challenge test value. Similar analysis of the 2-hour oral glucose tolerance test value revealed an increase in the incidence of nonelective operative deliveries and a decrease in the percentage of infants discharged home with their mother where values were greater than 180 mg/dl. However, when women with gestational diabetes were excluded from analysis, neither the glucose challenge test nor the 2-hour glucose tolerance test measurements were related to adverse outcome. When analysis was limited to women with gestational diabetes, there was no clinically significant relationship between either glucose challenge test or 2-hour glucose tolerance test and the outcome parameters. Finally, when analysis was repeated according to diagnosis, women with gestational diabetes had a significantly higher risk of having nonelective operative delivery, premature delivery, growth-retarded neonate, 1-minute Apgar score less than 7, and neonatal hypoglycemia than women with normal oral glucose tolerance test results.(ABSTRACT TRUNCATED AT 400 WORDS)     

Hypoglycemia in infants of diabetic mothers: experience in a rural hospital

The purpose of this study was to identify which factors contribute to neonatal hypoglycemia in infants of diabetic mothers. A chart review of infants of diabetic mothers was undertaken noting the timing of blood glucose levels, symptoms of hypoglycemia, and interventions provided. The impact of maternal and gestational factors was assessed using marginal mixed models and Poisson regression. Of the 66 infants who had blood glucose determinations, none developed symptomatic hypoglycemia and none required intravenous glucose. The first 90 minutes of life had the lowest mean blood glucose level (mean, 3.01 mmol/L [54.24 mg/dL]) and nearly all of the blood glucose levels < 1.7 mmol/L (30 mg/dL). The risk of a blood glucose level < 1.7 mmol/L decreased with maternal age. With presumably tighter control of gestational diabetes, the risk of symptomatic hypoglycemia appears diminished. If glucose monitoring of asymptomatic newborns is to be performed, it need only be done in the first 2 hours of life.     

Population meta-analysis of low plasma glucose thresholds in full-term normal newborns

There is extreme variation in the definition of low plasma glucose levels in newborn infants in the first postnatal days, ranging from < 30 to < or = 60 mg/dL. The goal of the present study was to define low thresholds (< or = 5th percentile) of plasma glucose concentrations in full-term normal newborns during the first 72 hours of life. Population meta-analysis was performed on published studies of neonatal hypoglycemia ascertained by MedLine search. One-way analysis of variance was computed across the studies for each of the following four postnatal time periods: 1 to 2 (physiological nadir), 3 to 23, 24 to 47, and 48 to 72 hours. The estimated < or = 5th percentiles of neonatal hypoglycemia during 1 to 2, 3 to 23, 24 to 47, and 48 to 72 hours after birth were < or = 28, < or = 40, < or = 41, and < or = 48 mg/dL, respectively. Based on this statistical definition, we recommend that low thresholds of plasma glucose levels of 28, 40, and 48 mg/dL be adopted in full-term normal newborns at 1 to 2, 3 to 47, and 48 to 72 hours of life, respectively.     

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.     

Postpartum testing for antecedent gestational diabetes

Gestational diabetes is a predictor of glucose intolerance in subsequent pregnancies and in the nongravid state. Many pregnant women are not tested for gestational diabetes, although they or their offspring may show signs suggestive of antecedent hyperglycemia. We examined the diagnostic utility of a postpartum (within 48 hours), 100 gm, oral glucose tolerance test and cord plasma glucose, cord plasma C-peptide, and 2-hour neonatal plasma glucose tests to detect antecedent gestational diabetes in women with documented gestational diabetes (n = 37) or with normal glucose tolerance test results late in the third trimester (n = 28). The 1-hour, 2-hour, and incremental 1-hour + 2-hour [( 1-hour - fasting] + [2-hour - fasting]) [2-hour - fasting]) glucose values of the postpartum glucose tolerance test showed significant differences between study participants with and without gestational diabetes (164 +/- 30 versus 115 +/- 22, 145 +/- 31 versus 101 +/- 21, and 153 +/- 51 versus 67 +/- 33 mg/dl, respectively, p less than 0.025). Maternal fasting and 3-hour postpartum glucose tolerance test glucose, cord plasma glucose, cord plasma C-peptide, and 2-hour neonatal plasma glucose values showed no significant between-group differences. Receiver operating characteristic curve analyses for these tests indicated that the incremental 1-hour + 2-hour postpartum glucose tolerance test glucose values best sustain test specificity at the low test threshold values necessary for high test sensitivity. A threshold of 110 mg/dl for this test yielded a predicted specificity of 90% and sensitivity of 80% with regard to antecedent gestational diabetes.     

Correlation between first- and early third-trimester glucose screening test results

One hundred twenty-four normal gravidas had paired first- and early third-trimester (26-32 weeks) 1-hour oral glucose screening tests performed. First-trimester oral glucose screening test values correlated significantly with third-trimester glucose screening test results for the entire population, for whites and non-whites, and for normal-weight and obese patients. First-trimester oral glucose screening test values at or below 110 mg/dL were seldom associated with third-trimester oral glucose screening test results at or above 135 mg/dL and were not associated with abnormal 3-hour glucose tolerance test (GTT) results. Nine of the gravidas (7.3%) were diagnosed with gestational diabetes mellitus during the third trimester, all of whom had first-trimester glucose screening test results above 110 mg/dL. The difference in incidence of gestational diabetes mellitus between gravidas having first-trimester glucose screening test results at or below 110 mg/dL (0%) and those having values above 110 mg/dL (16.4%) was highly significant (P less than .0001). For patients with first-trimester glucose screening test values at or below 110 mg/dL, third-trimester glucose screening may be unnecessary. In contrast, for gravidas having first-trimester glucose screening test results at or above 135 mg/dL, there is a high positive predictive value for elevated repeat glucose screening test results during the early third trimester. Patients having elevated first-trimester glucose screening values at or above 140 mg/dL are at particularly high risk for elevated glucose screening test results later in pregnancy and should forego repeat 1-hour third-trimester glucose screening in favor of a direct third-trimester 3-hour GTT.     

Hypoglycemia during the 100-g oral glucose tolerance test: incidence and perinatal significance

OBJECTIVE: To estimate and report the incidence and perinatal significance of hypoglycemia during the 100-g oral glucose tolerance test in pregnant women. METHODS: Over a 3-year period, we analyzed the incidence and perinatal outcome of pregnant women who experienced hypoglycemia, defined as a plasma glucose level of 50 mg/dL or less while undergoing the 100-g oral glucose tolerance test. The study group included women who delivered singletons at term. Women who underwent the 100-g oral glucose tolerance test during the same period and had no hypoglycemia served as the control group. RESULTS: A total of 805 women were included in the study, which comprised 51 women (6.3%) who experienced hypoglycemia during the test and 754 women in the control group. Gestational diabetes mellitus was diagnosed in 5/51 (9.8%) women in the study group, compared with 216/754 (28.6%) women in the control group (P < .03), and the neonates born to these women had significantly lower birth weights. CONCLUSION: The incidence of reactive hypoglycemia during the 100-g oral glucose tolerance test in our population is 6.3%. Women who experience hypoglycemia during the test have a significantly lower incidence of gestational diabetes and neonatal birth weights.     

Can glucose tolerance test predict fetal hyperinsulinism?

Objective To establish cut off levels for oral glucose tolerance test in pregnancy using fetal hyperinsulinism as a clinical endpoint.
Design Capillary blood glucose levels at 0, 1, and 2 hours after the ingestion of either 1 g/kg or 75 g glucose, at 28 (SD 5) weeks of gestation were analysed in 220 women with elevated amniotic fluid insulin levels [≥ 42 pmol/L (≥ 7 μU/mL)] after a mean (SD) of 31 weeks (3) and in 220 nondiabetic controls.
Results In women with elevated amniotic fluid insulin levels the mean (SD) capillary blood glucose values at 0, 1, and 2 hours were 5.2 mmol/L (1.0) [94 mg/dL (18)], 10.5 mmol/L (1.4) [189 mg/dL (25)] and 8.2 mmol/L (2.0) [147 mg/dL (36)], respectively. The one-hour value had the highest sensitivity to predict elevated amniotic fluid insulin levels. The 5th centile of the one-hour blood glucose levels representing a detection rate of 95% was 8.9 mmol/L (160 mg/dL).
Conclusion Glucose cut off levels in most established oral glucose tolerance test criteria are too high, to accurately predict amniotic fluid hyperinsulinism. A one-hour test may be sufficient for detecting amniotic fluid hyperinsulinism. Since different loads (1 g/kg, 75 g or 100 g) and blood fractions (venous plasma or capillary blood) have minimal impact on oral glucose tolerance test results, a single one-hour cut off of 8.9 mmol/L (160 mg/dL), independent of the sampling method, may be appropriate for the diagnosis of gestational diabetes mellitus severe enough to cause amniotic fluid hyperinsulinism.     

Use of intravenous fluids before cesarean section: effects on perinatal glucose, insulin, and sodium homeostasis

Perinatal glucose, insulin, and sodium homeostases were assessed in relation to antepartum intravenous infusions administered to 59 normal mothers undergoing cesarean section at term without labor under epidural anesthesia. Group A (N = 20) received 1 L of Ringer's lactate without dextrose during one hour; group B (N = 20), 1 L of 5% dextrose in water during one hour; and group C (N = 19), 1 L of 5% dextrose in water during two and one half hours. Mean maternal and fetal serum glucose and insulin and sodium concentrations at delivery differed among all groups in direct relationship to the rate of glucose infusion. Neonatal hypoglycemia (30 mg/dL or less) correlated with the presence of a glucose infusion, a maternal glucose concentration of 117 mg/dL or greater, and an umbilical venous insulin concentration of 26 microU/mL or greater. Among group A patients who received sodium, and group B and C patients who did not, fetal hyponatremia (umbilical venous sodium 130 mEq/L or less) correlated with the absence of sodium in the prepartum infusion. The results suggest that the antepartum administration of a balanced electrolyte solution without excess glucose infusion can minimize the incidence of fetal hyperglycemia and hyponatremia and neonatal hypoglycemia.     

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.     

Fetal hyperinsulinism and maternal one-hour postload plasma glucose level

OBJECTIVE: Fetal insulin concentrations reflect the intrauterine glucose load given the fetus by the mother. In this study, we assessed the association between maternal glucose levels during oral glucose tolerance testing and fetal cord insulin. METHODS: Pregnant women with an oral glucose tolerance test (OGTT) result were included in this prospective study. The patients were divided into 3 groups according to their 1-hour OGTT glucose concentration: up to 160 mg/dL (control, group I), 160-179 mg/dL (intermediate, group II), and gestational diabetes mellitus (GDM, group III). Patients with GDM were assigned to insulin therapy if blood glucose levels were not in the preferable range. RESULTS: Of the 930 patients who entered the study, 570 (61.3%) were assigned to group I, 76 (8.2%) to group II, and 284 (30.5%) to group III. The cord blood insulin value was significantly (P < .001, Mann-Whitney test) higher in group II (median, 12.8 microU/mL; range, 3-130 microU/mL) than in group I (median, 7.25 microU/mL; range, < 3-98 microU/mL). Cord blood insulin values were higher, albeit not significantly (P = .100, Mann-Whitney test), in group II than in group III (median, 9.9 microU/mL; range, < 3-61 microU/mL). CONCLUSION: Children whose mothers had a 1-hour value between 160 and 179 mg/dL had significantly higher cord blood insulin values than offspring of women with a 1-hour value below 160 mg/dL.     

Clinical predictors for a high risk for the development of diabetes mellitus in the early puerperium in women with recent gestational diabetes mellitus

OBJECTIVE: The purpose of this study was to identify which maternal, antepartum, or neonatal clinical parameters were predictive for a high risk of diabetes mellitus in the puerperium in women with recent gestational diabetes mellitus and to calculate the associated diabetes mellitus rates and odds ratios. STUDY DESIGN: One thousand six hundred thirty-six women underwent an oral glucose tolerance test within 1 to 4 months of delivery. Demographic, historic, and antenatal glycemic parameters and neonatal outcome parameters were tested by univariate and multivariate logistic regression for risk of postpartum diabetes mellitus. Continuous variables were divided into quartiles that compared the upper to lower quartile adjusted odds ratio and prevalence of diabetes mellitus. RESULTS: Postpartum diabetes mellitus was diagnosed in 230 women (14.1%) according to the American Diabetes Association criteria (1997). No maternal demographic or neonatal parameters were significantly associated with diabetes mellitus. The final model of independent predictors in decreasing significance included the highest fasting plasma glucose level during pregnancy, any fasting plasma glucose level of > or = 105 mg/dL (class A(2)), the area under the curve of pregnancy oral glucose tolerance test, gestational age at diagnosis, previous gestational diabetes mellitus history, and 50-g glucose challenge test results. The fasting plasma glucose level was the best discriminator, with a 21-fold (95% CI, 4.6-96.3) increased odds ratio comparing the 4th quartile (fasting plasma glucose level, >121 mg/dL; diabetes mellitus rate, 36.7%) to 1st quartile (fasting plasma glucose level, < 95 mg/dL; diabetes mellitus rate, 0.5%). The presence of previous gestational diabetes mellitus or current class A(2) gestational diabetes mellitus approximately doubled the odds ratio for diabetes mellitus. The odds ratio increased 3- to 4-fold when the area under the curve was > or = 33.36 min small middle dot g/dL (4th quartile) or the glucose challenge test was > or = 155 mg/dL (2nd-4th quartiles) and decreased > 50% if gestational diabetes mellitus was diagnosed at > 27 weeks (3rd-4th quartile). CONCLUSION: During pregnancy, the highest fasting glucose level, followed by the severity of glucose intolerance, and earlier gestational diabetes mellitus diagnosis were the best predictors for postpartum diabetes mellitus. Diabetic education should begin during pregnancy, especially for women who are identified to be at a high risk when they are highly motivated and under medical care.     

Clinical outcomes of pregnancy in women with type 1 diabetes(1)

OBJECTIVE:To evaluate predictors of neonatal hypoglycemia and macrosomia in 107 consecutive pregnancies in type 1 diabetic women. METHODS:We conducted a case record analysis of singleton type 1 diabetic pregnancies between January 1994 and January 1999 following institution of standardized management. RESULTS:The duration of diabetes in the women was 12.9 +/- 6.8 years, and 44 were primigravidas. The mean HbA1c throughout pregnancy was 7.2 +/- 0.8%. There was no relationship between neonatal blood glucose (checked before the second feed) and HbA1c at any point in pregnancy or mean pregnancy HbA1c (R = 0.20, P >.1). However, there was a negative correlation between neonatal blood glucose and maternal blood glucose during labor (R = -0.33, P <.001). When maternal blood glucose during labor was greater than 8 mM (144 mg/dL), neonatal blood glucose was usually less than 2.5 mM (mean 1.7 +/- 0.4 mM or 31 mg/dL). There was no relationship between mean HbA1c and birth weight (R = 0.02, P >.1) or between maximum insulin dose and birth weight (R = 0.09, P >.1). Fetal abdominal circumference measured by ultrasound at 34 weeks correlated strongly with birth weight (R = 0.72, P <.001). CONCLUSION:Neonatal hypoglycemia correlates with maternal hyperglycemia in labor, not with HbA1c during pregnancy. Macrosomia does not correlate with HbA1c during pregnancy.     

Glucose screening in Mexican-American women

OBJECTIVE: We sought to describe the predictive value for gestational diabetes mellitus (GDM) using different glucose challenge test thresholds in Mexican-American women. METHODS: A prospective population-based study of 6,857 gravid women, who were tested with a 50-g glucose challenge test at 24-28 weeks of gestation, was performed. A screening value of 130 mg/dL or greater was followed by a 3-hour, 100-g oral glucose tolerance test. Gestational diabetes mellitus was diagnosed by 2 or more abnormal values using the Carpenter and Coustan criteria. For purpose of analysis, GDM diagnosis was categorized with glucose challenge test values in 10-mg/dL increments. A comparison between Carpenter-Coustan and the National Diabetic Data Group criteria for GDM diagnosis was performed for each glucose challenge test threshold category. Sensitivity and specificity for GDM diagnosis were further calculated for different glucose challenge test thresholds (130, 135, and 140 mg/dL). RESULTS: Overall, GDM was diagnosed in 469 of 6,857 (6.8%) women, and one abnormal oral glucose tolerance test value was tested in 351 of 6,857 women (5.1%). Normal glucose challenge test results (threshold less than 130 mg/dL) were obtained in 4,316 of 6,857 women. An elevated glucose challenge test value increases the risk of GDM, but even in high glucose challenge test thresholds (more than 180 mg/dL), the predictive value for GDM was only 50%. The sensitivity and specificity for GDM diagnosis using 3 different glucose challenge test thresholds were as follows: threshold 130 mg/dL or more: 97% and 63%; threshold 135 mg/dL or more: 91% and 73%; and threshold 140 mg/dL or more: 85% and 78%, respectively. CONCLUSION: Data suggests that an elevated glucose challenge test level cannot be used as a single diagnostic tool for GDM even in high test thresholds. A threshold of 130 mg/dL may be recommended as a screening threshold for GDM in Mexican-American women. LEVEL OF EVIDENCE: II-3     

The effect of oral ritodrine therapy on glucose tolerance in pregnancy

Intravenous ritodrine therapy can cause significant deterioration of maternal glucose homeostasis. We investigated the effect of full maintenance oral ritodrine therapy (120 mg/day) on glucose tolerance in the early third trimester with the use of 50 gm 1-hour screens followed by 100 gm 3-hour oral glucose tolerance tests if the screen level was greater than or equal to 140 mg/dl. Four hundred ninety-one patients were studied, 42 of whom were receiving oral ritodrine therapy. Twenty-one percent of the ritodrine-treated women had an abnormal 1-hour screen, which was not different from the 20% observed in women not receiving therapy. None of the treated group and 13% of the untreated group who had abnormal screens had abnormal oral glucose tolerance tests. The probability of an abnormal test after an abnormal 1-hour screen was also determined.