The Experts below are selected from a list of 165 Experts worldwide ranked by ideXlab platform
David F. Lewis - One of the best experts on this subject based on the ideXlab platform.
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A randomized clinical trial of daily Nonstress Testing versus biophysical profile in the management of preterm premature rupture of membranes.
American journal of obstetrics and gynecology, 1999Co-Authors: David F. Lewis, C.david Adair, Jonathan W. Weeks, P.scott Barrilleaux, Michael S. Edwards, Thomas J. GariteAbstract:Abstract Objective: Our purpose was to evaluate the ability of 2 different antepartum Testing modalities to predict infectious morbidity in patients with preterm premature rupture of membranes. Study Design: During a 36-month period, patients with preterm premature rupture of membranes (at 23 to 34 weeks of gestation) were randomly assigned to either a daily Nonstress Test or a biophysical profile, after a 24-hour observational period. We used the original scoring system of Manning et al for the biophysical profile, with a score of ≤6 considered abnormal. Nonstress Test results were considered abnormal if the Test was nonreactive or if the patient had late decelerations or significant variable decelerations; abnormal results led to further evaluation with a biophysical profile. Results of the last Test before delivery were evaluated to determine whether infectious complications had been predicted. Results: One hundred thirty-five patients were enrolled in the study. Demographics, pregnancy characteristics, and neonatal outcomes were similar. Neither the daily Nonstress Test nor the daily biophysical profile had good sensitivity for predicting infectious complications (39.1% and 25.0%, respectively). However, both had good specificity (84.6% and 92.6%, respectively). Positive and negative predictive values were 52.9% and 75.9%, respectively, for the daily Nonstress Test and 66.7% and 68.4%, respectively, for the daily biophysical profile. Cost was significantly higher in the daily biophysical profile group. Nonstress Testing of patients at
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Correlation of amniotic fluid index and Nonstress Test in patients with preterm premature rupture of membranes.
American Journal of Obstetrics and Gynecology, 1991Co-Authors: James A. Harding, David F. Lewis, David M. Jackson, Carol Major, Michael P. Nageotte, Tamerou AsratAbstract:The amniotic fluid index and the Nonstress Test are commonly used in the expectant management of preterm premature rupture of membranes. This study was designed to investigate the interrelationship of the Nonstress Test and the amniotic fluid index during the preterm rupture of membranes latency period. Fifty patients with preterm premature rupture of membranes for greater than 48 hours were prospectively followed with daily 1-hour Nonstress Tests and blinded, daily amniotic fluid index examinations (totaling 422 evaluations). The overall average daily amniotic fluid index was statistically lower in the earlier gestations and nulliparous patients but was not influenced by the fetal position or nonlaboring uterine activity. An increased incidence of variable decelerations and nonreactive Nonstress Tests was associated with a significantly lower overall average daily amniotic fluid index, but these differences were beyond the standard precision of the amniotic fluid index examination. The daily Nonstress Test appears to identify clinically significant lower fluid volumes during the latency period and should remain the mainstay in the management of preterm premature rupture of membranes.
Lawrence D. Devoe - One of the best experts on this subject based on the ideXlab platform.
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antenatal fetal assessment contraction stress Test Nonstress Test vibroacoustic stimulation amniotic fluid volume biophysical profile and modified biophysical profile an overview
Seminars in Perinatology, 2008Co-Authors: Lawrence D. DevoeAbstract:Antenatal fetal assessment was introduced into the United States in the 1970s. The initial antepartum Test, the oxytocin challenge Test, later renamed as the contraction stress Test, became the gold standard for fetal surveillance. Its labor intensive requirements and contraindications made it inapplicable to some high-risk pregnancies. Other Testing schemes were developed subsequently, the Nonstress Test and its alternative, vibroacoustic stimulation, the semiquantitative assessment of amniotic fluid volume, the biophysical profile and its modified version, the modified biophysical profile. This article is a brief critical review of these Testing methods and focuses on the following: (1) physiologic bases; (2) Testing methodologies; (3) supportive evidence from randomized controlled and observational trials; and (4) areas needing further investigation.
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Nonstress TestING AND CONTRACTION STRESS TestING
Obstetrics and gynecology clinics of North America, 1999Co-Authors: Lawrence D. DevoeAbstract:Antepartum fetal heart rate (FHR) Testing, including the Nonstress Test and contraction stress Test, has evolved in clinical usage over the past 3 decades. Although the Nonstress Test has become a standard of care in high-risk pregnancy, it has been modified by the use of fetal stimulation (vibroacoustic stimulation) and the addition of automated fetal movement recording (actocardiotocography). In all of its formats, antepartum FHR Testing has been associated with reduction of preventable fetal loss. More recently, there have been attempts to improve Test efficacy by computer-enhanced approaches.
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Neural network prediction of Nonstress Test often should we perform Nonstress Tests? results: How
1995Co-Authors: Lawrence D. Devoe, Ernest Carlton, Pallia PrescottAbstract:OBJECTIVE: Our purpose was to predict outcomes and optimal intervals for Nonstress Tests of term gravid women with neural networks. STUDY DESIGN: We studied 100 normal term patients whose 30-minute Nonstress Tests, performed on 5 consecutive days, were computer analyzed for the following elements: fetal heart rate baseline, variability, signal loss, accelerations (> 15 beats/min), and decelerations. The training set used 65 patients; the Testing, 35 patients. Nonstress Test data (days 1 to 4) were inputs; day 5 data were training patterns. Networks for each Nonstress Test element used Brainmaker Macintosh 1.0 (California Scientific Software, Nevada City, Calif.) trained to 0.12 tolerance. Actual fetal heart rate elements and their daily differences were compared with predictions by the networks and multiple regressions. RESULTS: There was little difference between networks using daily or alternate-day inputs for predicting Test performance on day 5; networks using Test intervals > 2 days could not be trained to tolerance. Long-term fetal heart rate variation was the Nonstress Test element best predicted. Daily differences networks provided better prediction of all day 5 data than did actual daily values networks or multiple regression formulas. CONCLUSIONS: Baseline long-term fetal heart rate variability seems to be the most predictable fetal heart rate element over time and should merit more consideration in overall fetal Testing. Fetal heart rate elements are not easily predicted by any method for intervals longer than 2 days. Using longer Test intervals might run a greater risk for unanticipated changes in Nonstress Test outcomes, even when fetal condition is normal (AM J OBSTET GYNECOL 1995;173:1128-31 .)
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Neural network prediction of Nonstress Test results: how often should we perform Nonstress Tests?
American journal of obstetrics and gynecology, 1995Co-Authors: Lawrence D. Devoe, Ernest Carlton, Paula PrescottAbstract:Abstract OBJECTIVE: Our purpose was to predict outcomes and optimal intervals for Nonstress Tests of term gravid women with neural networks. STUDY DESIGN: We studied 100 normal term patients whose 30-minute Nonstress Tests, performed on 5 consecutive days, were computer analyzed for the following elements: fetal heart rate baseline, variability, signal loss, accelerations (>15 beats/min), and decelerations. The training set used 65 patients; the Testing, 35 patients. Nonstress Test data (days 1 to 4) were inputs; day 5 data were training patterns. Networks for each Nonstress tet element used Brainmaker Macintosh 1.0 (California Scientific Software, Nevada City, Calif.) trained to 0.12 tolerance. Actual fetal heart rate elements and their daily differences were compared with predictions by the networks and multiple regressions. RESULTS: There was little difference between networks using daily or alternate-day inputs for predicting Test performance on day 5; networks using Test intervals >2 days could not be trained to tolerance. Long-term fetal heart rate variation was the Nonstress Test element best predicted. Daily differences networks provided better prediction of all day 5 data than did actual daily values networks or multiple regression formulas. CONCLUSIONS: Baseline long-term fetal heart rate variability seems to be the most predictable fetal heart rate element over time and should merit more consideration in overall fetal Testing. Fetal heart rate elements are not easily predicted by any method for intervals longer than 2 days. Using longer Test intervals might run a greater risk for unanticipated changes in Nonstress Test outcomes, even when fetal condition is normal.
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The Nonstress Test. Reassessment of the "gold standard".
Clinics in perinatology, 1994Co-Authors: Debra J. Ware, Lawrence D. DevoeAbstract:The Nonstress Test (NST) has been a durable cornerstone of antenatal Testing. This article deals with its background, physiologic basis, clinical applications, and current role in assessment schemes. Few randomized studies have been performed to assess its sole contribution to evaluating fetal well-being. The best contemporary data suggest that fetal well-being is best served by using the NST as a primary screening Test that is supported by some other measure of fetal assessment such as ultrasonographic evaluation of growth or amniotic fluid volume.
Daniel W. Byrne - One of the best experts on this subject based on the ideXlab platform.
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Comparison of visual and computerized interpretation of Nonstress Test results in a randomized controlled trial.
American Journal of Obstetrics and Gynecology, 1999Co-Authors: Luis A. Bracero, Sylvia Morgan, Daniel W. ByrneAbstract:Abstract Objective: This study Tested the null hypothesis that the number of fetal surveillance Tests and perinatal outcomes would not differ statistically between pregnancies randomized to visual or computerized interpretation of antepartum Nonstress Test results. Study Design: A prospective, randomized controlled trial was conducted, which required a sample size of 404 patients. By using a random-number table with assignment codes concealed in opaque envelopes, half of the patients were randomized to computerized interpretation of Nonstress Test results and half to standard visual interpretation of Nonstress Test results. The amount of antepartum Testing and the perinatal outcome were measured and compared between the groups. Logistic regression analysis was used to control for maternal risk factors while morbidity differences between the 2 groups were assessed. Results: The 2 randomized groups were similar at baseline, but the computerized interpretation group had significantly fewer biophysical profiles compared with the visual interpretation group (1.3 ± 1.8 vs 1.9 ± 2.1; P = .002). The patients in the computerized interpretation group spent less time per Test than patients in the visual interpretation group (12 vs 20 minutes; P = .038). After the 5 pregnancies with congenital anomalies were excluded, the overall perinatal outcome was similar in the 2 groups. The computerized interpretation group, however, had a slightly lower proportion of infants who required ≥2 days of neonatal intensive care (7.4% vs 12.4%; P = .086; odds ratio, 0.56; 95% confidence interval, 0.29-1.09). The average number of neonatal intensive care days was also slightly lower in the computerized interpretation group (0.4 vs 0.9; P = .105). Neither of these variables was statistically significant. Conclusions: Computerized interpretation of Nonstress Test results is associated with fewer additional fetal surveillance examinations, less time spent in Testing, and a similar length of stay in the neonatal intensive care unit compared with standard visual interpretation. (Am J Obstet Gynecol 1999;181:1254-8.)
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Comparison of umbilical Doppler velocimetry, Nonstress Testing, and biophysical profile in pregnancies complicated by diabetes.
Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine, 1996Co-Authors: Luis A. Bracero, R Figueroa, Daniel W. Byrne, H J HanAbstract:The purpose of this study was to determine which Test is best for predicting adverse outcomes in pregnancies complicated by diabetes: the Nonstress Test, biophysical profile, or umbilical artery velocimetry. We evaluated 207 singleton pregnancies complicated by diabetes within 1 week of delivery using the afore-mentioned pregnancy surveillance Tests. Adverse pregnancy outcome was defined as delivery before 37 weeks of gestation or the occurrence of fetal growth restriction, hypocalcemia, hypoglycemia, hyperbilirubinemia, respiratory distress syndrome, or fetal risk requiring cesarean delivery. The prognostic value of each of the three Tests was assessed, after controlling for the mothers' White classification and third trimester glycosylated hemoglobin value. Among the 207 pregnancies, 75 (36.2%) had an adverse outcome. In pregnancies in which the umbilical artery systolic to diastolic ratio was > or = 3.0, the relative risk of adverse outcome was 2.6 (95% confidence interval: 1.9-3.5, P < 0.001). For those with a biophysical profile < or = 6 the relative risk was 1.7 (95% confidence interval: 0.9-2.9, P = 0.109). Patients with a nonreactive Nonstress Test had a relative risk of 1.7 (95% confidence interval: 1.2-2.5, P = 0.009). Umbilical artery Doppler velocimetry was superior to either the Nonstress Test or the biophysical profile in identifying the subgroup of pregnancies complicated by diabetes that resulted in an adverse outcome.
Thomas J. Garite - One of the best experts on this subject based on the ideXlab platform.
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A randomized clinical trial of daily Nonstress Testing versus biophysical profile in the management of preterm premature rupture of membranes.
American journal of obstetrics and gynecology, 1999Co-Authors: David F. Lewis, C.david Adair, Jonathan W. Weeks, P.scott Barrilleaux, Michael S. Edwards, Thomas J. GariteAbstract:Abstract Objective: Our purpose was to evaluate the ability of 2 different antepartum Testing modalities to predict infectious morbidity in patients with preterm premature rupture of membranes. Study Design: During a 36-month period, patients with preterm premature rupture of membranes (at 23 to 34 weeks of gestation) were randomly assigned to either a daily Nonstress Test or a biophysical profile, after a 24-hour observational period. We used the original scoring system of Manning et al for the biophysical profile, with a score of ≤6 considered abnormal. Nonstress Test results were considered abnormal if the Test was nonreactive or if the patient had late decelerations or significant variable decelerations; abnormal results led to further evaluation with a biophysical profile. Results of the last Test before delivery were evaluated to determine whether infectious complications had been predicted. Results: One hundred thirty-five patients were enrolled in the study. Demographics, pregnancy characteristics, and neonatal outcomes were similar. Neither the daily Nonstress Test nor the daily biophysical profile had good sensitivity for predicting infectious complications (39.1% and 25.0%, respectively). However, both had good specificity (84.6% and 92.6%, respectively). Positive and negative predictive values were 52.9% and 75.9%, respectively, for the daily Nonstress Test and 66.7% and 68.4%, respectively, for the daily biophysical profile. Cost was significantly higher in the daily biophysical profile group. Nonstress Testing of patients at
T R Johnson - One of the best experts on this subject based on the ideXlab platform.
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Population differences affect the interpretation of fetal Nonstress Test results.
American journal of obstetrics and gynecology, 1998Co-Authors: T R Johnson, L L Paine, D M Strobino, F R WitterAbstract:The object of the study was to determine whether population differences exist with respect to outcomes of women with reactive and nonreactive Nonstress Test results. An epidemiologic evaluation was conducted on 2579 women who underwent Nonstress Tests in the Fetal Assessment Center of the Johns Hopkins Hospital within a week of delivery. Risk factors such as hypertension, diabetes, and postterm pregnancy were used in a logistic regression model to evaluate the ability of the Nonstress Test to predict outcomes including proxies of fetal distress and fetal and neonatal death. The sensitivities, specificities, and predictive values of the Nonstress Test for predicting these outcomes in cohorts of black and white women were also determined. The Nonstress Test was consistently more sensitive for black women than for white women in predicting several perinatal outcomes, but specificity and negative predictive value were consistently lower for black women. The positive predictive value for fetal and neonatal death was higher for white women than for black women. Although the nonreactive Nonstress Test result seemed to be predictive of certain perinatal events, the odds ratio for predicting perinatal mortality in any study population was no greater than when the Nonstress Test result was reassuring. Epidemiologic characteristics affecting Test results, such as disease prevalence and population differences, may lead to clinically significant differences in outcome prediction when these Tests' results are used. These differences should be considered in the implementation of antepartum fetal Testing programs.
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Population differences affect the interpretation of fetal Nonstress Test results
American Journal of Obstetrics and Gynecology, 1998Co-Authors: T R Johnson, L L Paine, D M Strobino, F R WitterAbstract:Abstract OBJECTIVE: The object of the study was to determine whether population differences exist with respect to outcomes of women with reactive and nonreactive Nonstress Test results. STUDY DESIGN: An epidemiologic evaluation was conducted on 2579 women who underwent Nonstress Tests in the Fetal Assessment Center of the Johns Hopkins Hospital within a week of delivery. Risk factors such as hypertension, diabetes, and postterm pregnancy were used in a logistic regression model to evaluate the ability of the Nonstress Test to predict outcomes including proxies of fetal distress and fetal and neonatal death. The sensitivities, specificities, and predictive values of the Nonstress Test for predicting these outcomes in cohorts of black and white women were also determined. RESULTS: The Nonstress Test was consistently more sensitive for black women than for white women in predicting several perinatal outcomes, but specificity and negative predictive value were consistently lower for black women. The positive predictive value for fetal and neonatal death was higher for white women than for black women. Although the nonreactive Nonstress Test result seemed to be predictive of certain perinatal events, the odds ratio for predicting perinatal mortality in any study population was no greater than when the Nonstress Test result was reassuring. CONCLUSIONS: Epidemiologic characteristics affecting Test results, such as disease prevalence and population differences, may lead to clinically significant differences in outcome prediction when these Tests' results are used. These differences should be considered in the implementation of antepartum fetal Testing programs. (Am J Obstet Gynecol 1998;179:779-83.)
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population differences affect Nonstress Test reactivity
Journal of Perinatology, 1991Co-Authors: L L Paine, F R Witter, D M Strobino, T R JohnsonAbstract:The Nonstress Test (NST) is the most widely used Test of fetal well-being. Recently it has been suggested that race may play a role in NST reactivity. The objective of this research was to explore population variables in addition to race that may influence NST reactivity. Study subjects were 1263 black and 658 white women who underwent NST in the week preceding delivery at a tertiary facility. Retrospective analysis of data from a comprehensive database was conducted. It was found that the percentage of black women with a nonreactive NST was more than three times the percentage of white women, and that from 35 weeks' to 42 weeks' gestation there were significantly fewer reactive NSTs for blacks than for whites (P less than .05). Racial differences in NST results persisted in a logistic regression analysis controlling for several population variables including pregnancy complications and demographic and behavioral factors (odds ratio 3.81; 95% CI 3.03 to 4.78). Regression analysis also confirmed that gestational age, maternal education, epilepsy, and smoking significantly influenced NST reactivity. These results indicate that population differences in NST reactivity exist at our facility. Further prospective study of population determinants of NST reactivity is needed to determine how race, Test indication, and other clinical, demographic, and behavioral variables should be used in interpretation of Tests of fetal well-being. Standard criteria for NST Testing may not be useful in all obstetrical populations.
