Biomedical subjects

O Langer

Publications and source records attributed to O Langer.

At least 19 recordsLinked to original sources

PubMed1995

Are labor abnormalities more common in shoulder dystocia?

OBJECTIVE: Our objective was to determine the association between labor abnormalities and shoulder dystocia. STUDY DESIGN: All consecutive cases of shoulder dystocia from January 1986 to August 1994 were reviewed (n = 276). For purposes of comparison a control group of vaginally delivered patients was randomly selected in a 2:1 ratio (n = 600). Charts were reviewed for demographic information, labor and delivery events, and neonatal outcome. RESULTS: Labor abnormalities were comparable in the shoulder dystocia and control groups, both in the active phase and in the second stage. When patients with diabetes and those with macrosomic infants were analyzed separately, no significant differences in labor abnormalities were identified. The rate of operative vaginal delivery was significantly higher in the shoulder group, and one third of the operative deliveries were midpelvic. In addition, the induction rate was higher in the shoulder group. CONCLUSIONS: Our data suggest that labor abnormalities may not serve as clinical predictors for subsequent development of shoulder dystocia, thus emphasizing the unpredictability of this condition.

Adult↗

PubMed1995

Glucose tolerance test periodicity: the effect of glucose loading.

OBJECTIVE: To test the hypothesis that glucose abnormality, as shown by glucose tolerance test (GTT) periodicity, is not affected by different glucose loads, allowing for the identification of gestational diabetes mellitus (GDM) under varying glucose challenges. METHODS: Eighty subjects were tested by multiple GTTs 1 week apart. Each woman served as her own control, undergoing a standard 3-hour, 100-g GTT; then, half of the subject group randomly underwent a 50-g and the other half a 75-g, 2-hour GTT. Subjects were classified using National Diabetes Data Group thresholds for the 100-g GTT. Those with two or more abnormal values were classified as gestational diabetic (GDM group); the rest of the women were considered to be nondiabetic. The projected time for the GTT to revert to fasting value, GTT periodicity, was then determined for each glucose load in the GDM and nondiabetic groups. RESULTS: All glucose values for the nondiabetic group were significantly lower at 1 and 2 hours than those for the GDM group, regardless of the glucose load (P < .04). There was a statistically significant difference within the GDM and nondiabetic groups between glucose values of the 100- and 50-g GTTs at 1 hour (P < .02) and between all loads at 2 hours (P < .04). The GTT periodicity for the 3-hour, 100-g test was significantly longer for patients with GDM, as shown previously (5.6 +/- 1.9 versus 3.2 +/- 1.7 hours, P < .0001). In addition, similar values were found for nondiabetic and GDM subjects for the 75-g (5.1 +/- 2 versus 3.6 +/- 1.8 hours, P < .04), but not the 50-g load (2.2 +/- .6 versus 1.34 +/- .8 hours, P < .01). CONCLUSION: Glucose tolerance test periodicity will identify subjects with GDM regardless of GTT load because the physiologic disturbance of glucose level measured by this time period remains comparably longer than in normal subjects. We speculate that the relatively shorter cycle of the 50-g load may reflect an insufficient challenge to pancreatic function.

Adult↗

PubMed1995

The effect of maternal obesity on the accuracy of fetal weight estimation.

OBJECTIVE: To determine if maternal obesity affects the accuracy of either clinical or sonographic fetal weight estimations. METHODS: In a year-long study, 998 singleton pregnancies of 26-43 weeks' gestation underwent both clinical (Leopold) and sonographic (Shepard and Hadlock) fetal weight estimation within 5 days of delivery (mean 1.1, 95% confidence interval 1.0-1.3). Patients were stratified into four different groups based on increasing maternal body mass index (BMI): underweight (less than 19.8), normal weight (19.8-26.0), overweight (26.1-29.0), and obese (more than 29.0). The various estimations of fetal weight were compared with actual birth weight, and the mean absolute percent error was calculated for each specific method and analyzed among the four BMI groups. RESULTS: For each method of weight estimation, there was no difference (specifically, no increase) in the magnitude of the absolute percent error with increasing maternal obesity. Regardless of maternal size, almost half of the weight predictions were within 5% of the actual birth weight. CONCLUSION: Increasing maternal obesity does not alter or decrease the accuracy of either clinical or sonographic fetal weight estimations. Therefore, fetal weight predictions provide equally accurate and valid guidelines for determining management decisions in women, regardless of body size.

Body Mass Index↗

PubMed1995

Efficiency of lower threshold criteria for the diagnosis of gestational diabetes.

OBJECTIVES: To determine the incidence of adverse outcome in normal untreated gravidas with minimal hyperglycemia, classified as having gestational diabetes mellitus (GDM) by threshold criteria lower than current standards; to determine how efficient the different criteria are in identifying infants at risk for morbidity; and to explore the pathophysiology of minimal hyperglycemia using the glucose tolerance test (GTT) periodicity concept. METHODS: Seven hundred eight subjects considered nondiabetic by current ACOG criteria were reclassified by the criteria of Coustan (fasting 95, 1 hour 180, 2 hours 155, and 5 hours 140 mg/dL), Sacks (96, 172, 152, and 131 mg/dL), or Langer (at least one abnormal ACOG value). Glucose tolerance test periodicity, the incidence of large for gestational age (LGA) neonates, and macrosomia were then determined for each gravida diagnosed as having GDM by these criteria. RESULTS: Both Coustan and Langer criteria identified a significantly greater incidence of LGA infants compared with non-GDM (23.6 and 25.3%, respectively, versus 14%, P < .05), and identified them as efficiently as current criteria, approximately one LGA infant for every four GDM subjects treated. The incidence of LGA did not differ between the Sacks GDM and non-GDM groups. Glucose tolerance test periodicity for newly diagnosed GDM gravidas was significantly longer than non-GDM for Coustan and Langer criteria (3.9 and 4.06 versus 3.3 hours, P < .01) but not for the Sacks criteria. CONCLUSION: Using lower threshold criteria to diagnose GDM identified morbidity at an incidence and efficiency comparable to current standards. These newly diagnosed GDM gravidas had abnormal GTT characteristics, with each group exceeding the 3.5-hour GTT periodicity limit previously found for nondiabetic gravidas. Sack's conversion of existing standards may be too low to efficiently identify pregnant subjects at risk for increased morbidity.

Adult↗

PubMed1995

Antenatal bleeding and fetal heart rate.

Objective of the paper was to determine the fetal heart rate (FHR) changes that occur in preterm fetuses whose mothers have suffered antepartum bleeding, versus uncomplicated controls. Over a 12-year span, 91 patients with significant antenatal bleeding (bleeding requiring inhospital observation) were examined and compared to 75 controls with uncomplicated normal pregnancies. None of the women were in labor and all were evaluated at 25-37 weeks' gestation. Excluded were: patients with any other complication (i.e., premature rupture of membranes, intrauterine growth retardation, diabetes, hypertension, collagen vascular disease, postuterine surgery, substance abuse and twins). Analysis of the FHR tracings included baseline heart rate, long-term FHR variability, and number and amplitude of FHR accelerations in 20-min segments. There was no difference in baseline heart rate in the preterm fetuses of pregnancies complicated by antepartum bleeding versus controls. However, the parameters associated with FHR reactivity (number of accelerations in 20 min, and amplitude of accelerations) were higher to a statistically significant degree in fetuses of pregnancies complicated by antenatal bleeding than in controls. Fetuses of mothers suffering antenatal bleeding exhibited significant higher rates of reactive FHR patterns at earlier gestational ages than did controls. In conclusion, there is a significant increase in FHR reactivity in pregnancies in which significant antenatal bleeding occurs, suggesting a probable acceleration in fetal central nervous system maturation in these fetuses.

Case-Control Studies↗

PubMed1995

Variations in oral glucose tolerance tests: the 100- versus 75-g controversy.

This study compared the results of a 75-g, 3-hour oral glucose tolerance test with those of a traditional 100-g oral glucose tolerance test. Thirty-two pregnant women participated in the study. Each patient served as her own control, undergoing both a 100- and a 75-g oral glucose tolerance test within 1 week. Despite a strong positive correlation between the results of the two tests, the 1-, 2-, and 3-hour glucose values of the 100-g glucose load were significantly higher than the comparable values of the 75-g oral glucose tolerance test. Sixteen of 32 women were diagnosed as having gestational diabetes mellitus using the National Diabetes Data Group criteria and the 100-g oral glucose tolerance test, whereas only 6 of these 16 women would have been identified with the 75-g oral glucose tolerance test. If data from one test are to be compared with the other, new thresholds of glucose abnormality need to be developed.

Administration, Oral↗

PubMed1995

Cultural diversity as a factor in self-monitoring blood glucose in gestational diabetes.

The routine use of self-monitoring of capillary blood glucose by pregnant diabetic patients currently provides the basis for both clinical management and ongoing investigation. Strategies must therefore be developed to ensure that these data are reliable and accurately reported by patients and are not influenced by diverse socioeconomic levels or varied geographic locations. To explore this issue, we used glucose reflectance meters with a memory microchip capable of storing up to 440 consecutive blood glucose determinations. Two diverse groups of women from Texas and New York who had gestational diabetes performed self-monitoring of blood glucose from diagnosis until delivery. Both groups recorded their blood glucose results daily in a logbook. The reporting performance of all the participating subjects resulted in an actual compliance rate of 60% to 70% of testings required of the patients. Comparison of African-American, Mexican-American, and white populations revealed no significant differences in patient performance or compliance. Moreover, no differences were found between the groups at different geographic locations (New York, Texas) in patients' willingness and ability to comply with the regimen of self-monitoring blood glucose. These findings suggest that the use of memory reflectance meters, in conjunction with patient education and positive interaction between patient and care provider, will result in high patient compliance regardless of socioeconomic level or ethnic diversity.

Adult↗

PubMed1994

Comparative placental transport of oral hypoglycemic agents in humans: a model of human placental drug transfer.

OBJECTIVE: This study compares the human placental transport of glyburide, glipizide, chlorpropamide, and tolbutamide. STUDY DESIGN: The recirculating single cotyledon human placenta model tested maternal-to-fetal transport in term placentas perfused immediately after delivery. Drug levels were measured by high-performance liquid chromatography and liquid scintillation spectrometry, and transport rates were calculated by comparing maternal and fetal concentrations. RESULTS: The transport of these substances differed significantly over a tenfold range (analysis of variance, p < 0.0008). A significant association exists by multiple linear regression between drug transfer and molecular weight, dissociation constant, and the octanol-water partition coefficient (R2 = 0.91, p < 0.0001). CONCLUSIONS: There is significant variability in human placental transfer rates of the oral hypoglycemics, which strongly correlates with molecular properties. These data suggest that less fetal exposure may occur with second-generation sulfonylureas and anticipate that regression models may be useful in selecting agents that minimize placental transport to the fetus.

Administration, Oral↗

PubMed1994

Use of a more physiologic oral glucose solution during screening for gestational diabetes mellitus.

OBJECTIVES: We sought to compare in pregnant women deviations in glucose values, insulin values, and the occurrence of side effects between a "standard" 50 gm oral glucose solution (50 gm of glucose in 150 ml of fluid, 1.85 mol/L) versus a modified "physiologic" 50 gm oral glucose solution (50 gm of glucose in 450 ml of fluid, 0.62 mol/L) as a screening test for gestational diabetes mellitus. STUDY DESIGN: A total of 132 pregnant women underwent (1) a standard 50 gm, 1-hour oral glucose screening test, (2) a 50 gm, 1-hour oral glucose screening test using the modified solution, and (3) a 3-hour oral glucose tolerance test (with 100 gm of glucose in 300 ml of fluid, 1.85 mol/L). RESULTS: Compared with the "standard" regimen, both glucose and insulin values were significantly higher in the "modified" regimen 30 minutes after ingestion, indicating a more rapid absorption of glucose. Nausea and vomiting were greatly decreased with the modified glucose solution. The 1-hour glucose values were not statistically different. CONCLUSIONS: A more dilute, more palatable oral glucose solution can be used to screen for gestational diabetes mellitus, yielding more accurate results and eliminating unpleasant side effects.

Administration, Oral↗

PubMed1994

The effect of clinical chorioamnionitis on cord blood gas at term.

OBJECTIVE: We sought to determine the effect of clinical chorioamnionitis on cord blood gas values in term pregnancies not complicated by any other disease. STUDY DESIGN: 2200 consecutive deliveries were studied. Following exclusion of twins, non-viable malformations and stillbirths, as well as mothers with high-risk pregnancy diseases--i.e. hypertension, diabetes, preterm labor, third-trimester bleeding, IUGR, postdates, oligohydramnios, i.v. drug abused, decreased fetal movement, maternal viral infection, UTI or pneumonia (n = 897)--two groups of patients remained: term pregnancies complicated only by clinical chorioamnionitis (n = 81) and uncomplicated term pregnancies (n = 1246). RESULTS: Evaluation of mean cord blood gas values revealed a significant difference in pH, PO2, PCO2 and BE values, with the infants of mothers with clinical chorioamnionitis having lower pH values (7.23 +/- 0.07 vs. 7.28 +/- 0.07). However, evaluating the independent effect of chorioamnionitis on arterial cord blood pH (using a logistic regression model) showed that clinical chorioamnionitis, by itself, did not contribute to this change in arterial cord blood pH. CONCLUSION: Chorioamnionitis was neither the explanation nor the cause for differences in arterial cord blood pH found between the two groups in our study. In cases of chorioamnionitis, these differences were attributed to other factors, such as length of labor, mode of delivery, method of delivery and presence of meconium.

Adult↗

PubMed1994

Normal values of urinary albumin and total protein excretion during pregnancy.

OBJECTIVE: Our purpose was to determine the normal 24-hour excretion values of urinary albumin and total protein in healthy pregnant women. STUDY DESIGN: We evaluated 270 healthy pregnant women < or = 35 years old without a history of diabetes, hypertension, pyelonephritis, preeclampsia, or renal or connective tissue disease. Adequacy of 24-hour collection was determined by creatinine excretion. RESULTS: The mean protein excretion in 24 hours was 116.9 mg, upper 95% confidence limit 259.4 mg. The mean albumin excretion in 24 hours was 11.8 mg, upper 95% confidence limit 28.7 mg. Both protein and albumin excretion increased after 20 weeks of gestation. No patient had evidence of microalbuminuria, defined as urinary albumin excretion > 30 mg/L. CONCLUSION: These data support 260 mg per 24 hours of urinary protein and 29 mg per 24 hours of albumin as the upper limit of normal in pregnancy. Albumin accounts for a small fraction of total urinary protein excretion.

Adult↗

PubMed1994

Intensified versus conventional management of gestational diabetes.

OBJECTIVE: We tested the hypothesis that intensified management of gestational diabetes mellitus on the basis of stringent glycemic control, verified glucose data, and adherence to an established criterion for insulin initiation results in near normoglycemia control and reduction of adverse outcomes. STUDY DESIGN: A prospective, population-based study compared the effect on perinatal outcome of conventional (n = 1316) and intensified (n = 1145) management. Group assignment was based on availability of memory-based reflectance meters at entry to the program. A contemporaneous randomized control group (nondiabetic, n = 4922) was selected. RESULTS: The diabetic groups were comparable in demographic characteristics and in factors associated with higher risk for adverse pregnancy outcome, such as previous macrosomia, previous gestational diabetes mellitus, and family history of diabetes. The control group was younger, less obese, and had a lower rate of previous macrosomia. The intensified management group had rates of macrosomia, cesarean section, metabolic complications, shoulder dystocia, stillbirth, neonatal intensive care unit days, and respiratory complications lower than those in the conventional management group and comparable to those of the nondiabetic controls. Other maternal complication rates, such as for preeclampsia, chronic hypertension, and infection, were similar for the three groups. Mean blood glucose levels were a good predictor of perinatal outcome. Gestational age at delivery, previous history of macrosomia, and overall mean blood glucose levels were the only significant predictors of birth weight percentile in both diabetic groups (logistic regression). CONCLUSION: The intensified management approach is significantly associated with enhanced perinatal outcome. This management strategy clarifies the relationship between glycemic control and neonatal outcome.

Birth Weight↗

PubMed1994

Is fetal heart rate variability a good predictor of fetal outcome?

OBJECTIVE: The purpose of this study was to investigate, in a prospective manner, whether fetal heart rate (FHR) variability serves as a reliable single predictor of fetal outcome. METHODS: We undertook a prospective study of 2,200 consecutive deliveries. Preterms < 37 weeks, twins, stillbirths and fetal malformations were excluded from the study. FHR tracings were analyzed for variability in every delivery. Three windows were evaluated: 1) early in labor (30 min); 2) in the active phase of labor - 1 h prior to complete cervical dilatation (30 min); and 3) throughout the second stage of delivery, in segments of 30 min. Using the tracings taken at admission and prior to delivery, FHR variability was scored according to five previously used evaluative methods, and was correlated to the following three fetal outcome parameters: a) arterial cord blood pH < 7.2, > 7.2; b) 5-min Apgar >6, < 7; and c) immediate outcome ('good' defined as newborn going home after 2-5 days, with no neonatal intensive care unit (NICU) admission). RESULTS: 1. The majority of cases with adverse fetal outcome exhibited good FHR variability (mean, 80%). 2. Low FHR variability is not common in newborns with adverse general outcome (mean, 11.5%). 3. The predictability of FHR variability (using the five most common scoring methods) for evaluating adverse fetal outcome revealed low sensitivity (mean, 20.3%) and low predictive value (mean, 11.6%). CONCLUSION: FHR variability by itself cannot serve as the only indicator of fetal wellbeing. The presence of low variability should alert the physician; however, good FHR variability should not be interpreted as reassuring.

Analysis of Variance↗

PubMed1994

Hypertensive diseases in pregnancy.

Hypertension is one of the most common complications of pregnancy, with potential adverse effects for both mother and fetus. Controversy exists in the classification and differential diagnosis of the hypertensive disorders, which include preeclampsia-eclampsia, chronic hypertension, preeclampsia superimposed on chronic hypertension, and transient hypertension. This review discusses the problems clinicians face in the diagnosis of these disorders, as well as key management issues. With proper diagnosis and treatment, pregnant hypertensive patients should be spared the most serious sequelae of hypertension, and most should enjoy a successful pregnancy outcome.

Algorithms↗

PubMed1994

Meconium-stained amniotic fluid: increased risk for adverse neonatal outcome.

OBJECTIVE: To determine the risk of adverse neonatal outcome associated with meconium-stained amniotic fluid independent of that related to antepartum or intrapartum abnormalities. METHODS: A cohort of 2200 consecutive deliveries was examined and the fetal heart rate (FHR) tracings analyzed independently. Singleton term pregnancies without fatal malformations were stratified by the consistency of meconium and compared. RESULTS: Moderate or thick meconium increased the risk for adverse outcome more than threefold (relative risk 3.2, 95% confidence interval 2.0-5.2). This risk was independent of fetal heart tracing abnormalities or maternal hypertensive, kidney, or heart disease. CONCLUSION: Thick meconium alone should alert the physician to a high-risk fetal condition. This phenomenon requires continuous FHR monitoring and reassurance of fetal well-being by acid-base assessment or the equivalent, regardless of maternal disease status or the presence of abnormal FHR tracings.

Adult↗

PubMed1994

Emotional adjustment to diagnosis and intensified treatment of gestational diabetes.

OBJECTIVE: To determine, in women having newly diagnosed gestational diabetes mellitus, the effect of intensified treatment on the patients' emotional status and the relation between metabolic control and emotional well-being. METHODS: English-speaking women with newly diagnosed gestational diabetes mellitus (N = 206) and nondiabetic controls (N = 95) were compared for maternal characteristics and test results on the Profile of Mood States-Bipolar test, a standardized Likert scale measuring mood dimensions in terms of six bipolar affective states. Women with gestational diabetes mellitus were stratified according to treatment modality (diet or insulin therapy) and level of glycemic control (good control, mean blood glucose less than 105 mg/dL; poor control, mean blood glucose 105 mg/dL or greater). Because emotional profile can be influenced by actual glucose values depicted on the memory reflectance meter, glucose determinations were categorized as hypoglycemia, normoglycemia, mild hyperglycemia, and hyperglycemia. An Average Mood Disturbance score was used to determine the relation between total mood status and categories of glucose determinations. RESULTS: There was no significant difference between women with gestational diabetes mellitus in either the diet- or insulin-managed group and nondiabetic controls on each of the subscales of the Profile of Mood States-Bipolar test. Patients with stringent glycemic control were less distressed than those having poor control. Intensified therapy (self-monitoring of blood glucose levels and liberal use of insulin) for gestational diabetes mellitus does not negatively affect patients' emotional status. Insulin therapy by multiple injection does not adversely affect mood state. Stepwise regression analysis found a significant association between Average Mood Disturbance score and the number of determinations within the normoglycemic and hyperglycemic categories, marital status, and maternal age. CONCLUSION: Intensified management of newly diagnosed gestational diabetes mellitus does not increase patient anxiety and depression. Moreover, achievement of glycemic control contributes to patient reassurance. Psychological adjustment to the temporary disease state is then equal to that of a nondiabetic individual.

Adaptation, Psychological↗

PubMed1993

Doppler velocimetry in pregnant patients with sickle cell anemia.

Women with sickle cell anemia have an increased risk of bearing low-birth-weight (LBW) progeny. To establish prognostic indicators of neonatal outcome, 15 women with sickle cell anemia were followed through their pregnancies with the use of umbilical and uterine Doppler flow velocimetry. The systolic/diastolic ratios obtained were correlated with neonatal birth weight, gestational age, and birth weight percentile. Pregravid hemoglobin levels, reticulocyte counts, dense cell numbers, percentage hemoglobin F, and indirect bilirubin and lactate dehydrogenase levels were also determined, and statistical analysis was performed to assess whether any of these parameters would be useful in conjunction with velocimetry. We report here that, in sickle cell anemia, prenatal umbilical and uterine Doppler velocimetry ratios correlate inversely and significantly with neonatal birth weight (P < 0.005 and P < 0.002, respectively). In addition, prenatal maternal HbF levels also correlate significantly with Doppler velocimetry readings, an independent indicator of LBW progeny. Neither pregravid hemoglobin levels nor dense cell concentration correlates with Doppler umbilical and uterine flow velocimetry ratios determined during pregnancy. Pregravid high levels of HbF and velocimetry readings may serve to delineate a subset of sickle cell patients who may have different requirements for prenatal care. The possible mechanism for the detrimental effects of increased levels of fetal hemoglobin has not been clearly established, but it may involve increased propensity for vasoocclusion due to the unique rheology of the human placenta.

Adult↗

PubMed1993

Is lung maturation related to fetal growth in diabetic or hypertensive pregnancies?

The purpose of this study was to determine whether infants sufficiently affected by maternal diabetes or hypertension to exhibit abnormal growth (macrosomia, growth retardation) would also display significant alteration in timing of pulmonary maturity (delay or acceleration, respectively). We studied 874 consecutive women with fetal pulmonary maturity testing prior to delivery. Patients were stratified by birth weight into fetal size categories (small for gestational age [SGA], appropriate for gestational age [AGA], large for gestational age [LGA]). Cases were compared based on maternal disease, fetal size categories and pulmonary maturity testing results. Pulmonary maturity rates based on both phosphatidylglycerol (PG) and lecithin/sphingomyelin ratio (L/S) did not differ between term LGA infants of diabetic mothers (97%) and term LGA (80%) or AGA (97%) infants of non-diabetic, non-hypertensive mothers. When compared based on PG alone, there was no difference between the rate of positive PG in term AGA infants of non-hypertensive, non-diabetic mothers (75%) and that seen in the other pregnancy groups (33-80%). Breakdown by gestational age revealed no significant differences in maturity rates between the study groups. Macrosomic diabetic infants and growth-retarded hypertensive infants are no different from controls in their timing of fetal pulmonary maturation.

Amniotic Fluid↗