The abnormal fetal biophysical profile score. V. Predictive accuracy according to score composition

The relationship between last abnormal biophysical profile score, in total and by variable composition, and a spectra of abnormal perinatal outcome end points was examined in 525 fetuses. Highly significant inverse relationships between last test score and outcome were observed; relationships were linear for most end points and exponential for perinatal mortality end points. For biophysical profile scores less than or equal to 6, 25 of the 26 possible variable combinations were observed, at varying frequencies. For a biophysical profile score of 6, the positive predictive accuracy for some end points was significantly higher with either nonreactive nonstress test/fetal tone absent or nonreactive nonstress test/absent fetal breathing movement, and significantly lower with absent fetal breathing movement and decreased amniotic fluid volume. For a biophysical profile score of 4, the positive predictive accuracy for some end points was significantly higher with nonreactive nonstress test/absent fetal breathing movement/decreased amniotic fluid and was significantly lower with absent fetal movement/fetal breathing movement/fetal tone. No significant variation was observed for a biophysical profile score of 2. These data indicate that not all abnormal biophysical profile scores are equal.

Fetal assessment based on fetal biophysical profile scoring. IV. An analysis of perinatal morbidity and mortality

The relationship between the last biophysical profile score result and perinatal outcome was determined among a large referred population of high-risk pregnancies. A highly significant inverse linear correlation was observed for fetal distress, admission to neonatal intensive care unit, intrauterine growth retardation, 5-minute Apgar score less than 7, and umbilical cord pH less than 7.20 but not for the incidence of meconium or major anomaly. A highly significant inverse exponential (log 10) relationship was observed for perinatal mortality in total and by component parts and cause. These data strongly suggest the biophysical profile scoring method of fetal risk assessment is accurate and also provides insight into the extent of fetal compromise.

Fetal assessment based on fetal biophysical profile scoring. III. Positive predictive accuracy of the very abnormal test (biophysical profile score = 0)

The relationship between complete absence of all components of the fetal biophysical profile score (biophysical profile score = 0) and adverse perinatal outcome was examined. Twenty-nine of 28,655 fetuses studied (0.092%) had a last biophysical profile score of 0; 48.3% of these perinates died (14 of 29 fetuses), the majority of whom (11 of 14) were stillborn, with death occurring as early as 30 minutes to as long as 11 days after the last test. Three asphyxia-related neonatal deaths occurred despite aggressive and immediate intervention. All survivors exhibited at least one of the five discrete markers used to assess perinatal morbidity. The positive predictive accuracy of a biophysical profile score of 0, with mortality and morbidity used as end points, was 100%. These data indicate the very abnormal fetal biophysical profile score to be a perinatal emergency.

Severe fetal brain injury without evident intrapartum asphyxia or trauma

Two appropriate-for-dates term infants were born after uncomplicated labors and atraumatic deliveries. They were depressed at birth, developed seizures on the first day of life, and followed clinical courses compatible with hypoxic-ischemic encephalopathy. However, the umbilical cord vessel pH and blood gases were normal. The children are now severely retarded and have cerebral palsy. These cases prove that the events of labor and delivery may not be responsible for all cases of brain damage in surviving children.

Fetal assessment based on fetal biophysical profile scoring: experience in 19,221 referred high-risk pregnancies. II. An analysis of false-negative fetal deaths

The incidence of false-negative fetal death, which is defined as stillbirth unrelated to major anomaly or alloimmunization occurring after a last normal fetal biophysical score, was determined in 19,221 referred high-risk pregnancies. The calculated rate of fetal death after a last normal test was 0.726/1000 (14 deaths), which remained relatively constant despite a progressive increase in tests and patients studied. We conclude that a normal fetal biophysical profile score confers a high probability of perinatal survival.

Antepartum fetal risk assessment: the role of the fetal biophysical profile score

In the art of medicine we have always known that establishing an accurate diagnosis of health or disease is essential. An active search for the physical signs, both the time honoured and newly discovered, are a crucial step in achieving diagnostic accuracy, in monitoring disease progression, and in assigning prognosis. In extrauterine medicine it is common practice to gather together sets of biophysical data in order to determine immediate health, to monitor condition, and to estimate prognosis: witness the use of vital signs, and, in the newborn, the Apgar score. The providers of perinatal care have known since biblical days that fetal biophysical activities were a reflection of fetal condition (Luke: Chapter 1, Verses 44-45), yet lacked the ability to categorize these activities in an objective and complete manner. The introduction of dynamic ultrasound imaging methods to perinatal medicine at last create the window through which the principles of extrauterine medicine may now be applied to the intrauterine patient--the fetus. Fetal biophysical profile scoring is a method that utilizes this new wealth of information to differentiate the normal fetus from the fetus at risk for death or damage in utero. The method is based on the concept that the discrimination of fetal health and disease improves as more variables are considered. The now extensive clinical experience with the method, in which both overall (gross) and selected (corrected) perinatal death are reduced, while maintaining a remarkably low false negative predictive error, indicate the validity of the concept. Comparative studies lead us to believe that reliance upon single biophysical variables, such as fetal movement counts, or antepartum fetal heart rate monitoring, is no longer of sufficient accuracy to support its use as a sole measure of fetal condition. Looking forward, we anticipate that while the concept on which fetal biophysical profile scoring is based will remain unchanged, inclusion of additional variables is likely to occur. It seems likely that addition of new variables, as may be now measured using high-resolution dynamic ultrasound methods, both B-mode and Doppler, will improve diagnostic accuracy even more. We believe that the application of the current and future modified methods of composite fetal risk assessment will render the occurrence of the tragedy of perinatal loss even more infrequent. While the goal of complete elimination of perinatal deaths remain elusive, this method may be one step towards this goal.

Fetal biophysical profile scoring: selective use of the nonstress test

The fetal biophysical profile score was modified by selective use of the nonstress test. In 2712 study patients (7851 tests) the incidence of nonstress test was reduced to 2.7% with no measurable effect or test accuracy. The nonstress test was most useful in evaluation of abnormal ultrasound monitored variables.

Fetal assessment by biophysical profile scoring: 1985 update

In extrauterine medicine, physicians have come to rely upon sampling of multiple biophysical variables as a means of differentiating states of well-being and compromise. This basic tenet of medicine is expressed by obtaining an Apgar score or some variant in the newborn and as a measure of vital signs in later life. Few, if any, decisions regarding well-being are ever based on a single-variable assessment and, conversely, definition of compromise is rarely based upon a single variable. Through the use of dynamic ultrasound imaging it now becomes possible to visualize the fetus and its biophysical responses in health and disease. Through such visualization it becomes possible to bring to bear some of the basic principles that sustain extrauterine medicine on the intrauterine patient, the fetus. Fetal biophysical profile scoring describes a method that encompasses this concept. The results obtained by application of this method are promising. We would argue that consideration of multiple fetal biophysical variables will, in most instances, yield superior results to single-variable monitoring alone. Hence we have abandoned antepartum fetal heart rate testing as the sole method of fetal risk assessment and used the tool only in conjunction with others of the many variables that may be monitored by dynamic ultrasound methods. This concept of multiple-variable analysis as the superior method for fetal assessment seems clear and well-justified. It is our opinion, however, that the concept of fetal bioprofile scoring may be more important than the method itself in its original description.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrasound evaluation of amniotic fluid: outcome of pregnancies with severe oligohydramnios

Severe oligohydramnios, defined as a condition in which the largest pocket of amniotic fluid measures less than 1 cm in its vertical axis as determined by an ultrasound method, was observed in 113 patients in a population of 15,431 referred high-risk patients (0.7%). In all cases, intervention took place unless there was a recognized structural anomaly or extreme prematurity. Overall gross perinatal mortality was 132.7/1000, and the incidence of major anomaly was 13.3%. With intervention the corrected perinatal mortality rate was 17.7/1000, a rate not significantly different from that observed in the entire population. All end points of perinatal mortality were significantly increased in patients with severe oligohydramnios, in comparison with randomly selected control subjects with normal amniotic fluid. These findings are interpreted to indicate that severe oligohydramnios in a structurally normal fetus is an indication for delivery.

Weight-specific stillbirths and associated causes of death: an analysis of 765 stillbirths

An analysis of 765 consecutive stillbirths associated with 98,927 pregnancies during a 6-year interval showed significant differences for cause of death at specific weight categories. In addition, 57% of stillbirths occurred at infant weights of greater than or equal to 1500 gm. Hypoxia accounted for 43% of all stillbirths. The implications with respect to preventability and for changes in routine prenatal care through the incorporation of the several methods of fetal assessment currently available are discussed.

Cord prolapse: is antenatal diagnosis possible?

Cord presentation was diagnosed antenatally in nine patients at term referred for fetal ultrasound assessment (incidence of 0.61%). Seven patients were delivered by cesarean section; cord position was confirmed in four and suspected in three patients. There were two vaginal deliveries, one following spontaneous version and the other a stillbirth associated with cord prolapse.

Fetal assessment based on fetal biophysical profile scoring: experience in 12,620 referred high-risk pregnancies. I. Perinatal mortality by frequency and etiology

Fetal biophysical profile scoring was used as a method for antepartum fetal risk assessment in 12,620 high-risk patients referred in a 55-month interval. A total of 26,257 tests were performed on these patients (range, one to 18 tests per patient). Ninety-three perinatal deaths occurred (gross perinatal mortality rate, 7.37 per 1000) of which 62 (66.6%) were due to a major anomaly, seven were due to Rh disease (7.5%), and the remaining 24 deaths (25.8%) occurred in structurally normal fetuses. The corrected perinatal mortality rate was 1.90 per 1000. Eight structurally normal fetuses died within 1 week of a normal test result (corrected false negative rate, 0.634 per 1000). These data suggest fetal biophysical profile scoring is an accurate method for identification of the fetus at risk for perinatal death.

Sensitivity to retinal defocus with aspheric soft lenses--predictions and clinical validation

The purpose of this study was to obtain a numerically accurate discrete model of the effect of front aspheric soft lenses of various asphericities on the retinal illuminance profiles within the blur circles of a model eye. A computer program was developed for a model eye based on geometrical optics. The ray density was assumed to be proportional to the flux density or illumination. Retinal illuminance profiles are calculated for several values of defocus and asphericity. These results are validated by calculations based on modulation transfer functions (MTFs), observational data from contrast sensitivity and clinical results with Cals aspheric soft lenses. The results suggest that aspheric soft lenses maximize the central illuminance of blur circles and extend the range of desensitivity to retinal defocus in the eye to 4.00 D at the largest asphericity constant investigated.

Circadian rhythm in bladder volumes in the term human fetus

Circadian rhythms have been identified in a variety of maternal and fetal biophysical and endocrinologic parameters. The authors have undertaken a 24-hour study to identify the normal variation in fetal bladder volumes in the healthy, term human fetus. A significant decrease in fetal bladder volumes occurred between 2400 hours and 0600 hours when compared with other times of the day. It is suggested that this fall in fetal bladder volumes may be related to fetal cardiovascular or adrenal gland function.

Measurement of the rotational behaviour of virus particles during adsorption to the host cell surface

The rotational diffusion of bacteriophage epsilon 15 was measured before and after virus adsorption to outer membrane vesicles of the host Salmonella anatum. The virus capsid was labeled with eosin isothiocyanate, and the decay of transient dichroism following dye excitation by pulses of plane-polarized light was measured. From the data, the rotational diffusion constant of the unadsorbed virion and its hydrodynamic diameter were estimated and found to be consistent with electron microscopic measurements of the capsid dimensions. Addition of outer membrane vesicles of S. anatum to the virus suspension revealed the immobilization of the virus particles on the membrane surface.

Ultrasound evaluation of amniotic fluid volume. I. The relationship of marginal and decreased amniotic fluid volumes to perinatal outcome

Qualitative amniotic fluid volume determination is a routine part of fetal biophysical profile score testing. The relationship between oligohydramnios and poor perinatal outcome has been previously documented. We have undertaken a retrospective chart review relating qualitative amniotic fluid volume as determined at the time of last biophysical profile score assessment to perinatal outcome in 7582 referred high-risk obstetric patients. Gross and corrected perinatal mortality in association with normal qualitative amniotic fluid volume ranged from 4.65/1000 and 1.97/1000, respectively, to 187.5/1000 and 109.4/1000 in association with decreased qualitative amniotic fluid volume, respectively. The incidences of major congenital anomaly and intrauterine growth retardation were significantly related to qualitative amniotic fluid volume.

Ultrasound evaluation of amniotic fluid volume. II. The relationship of increased amniotic fluid volume to perinatal outcome

Qualitative amniotic fluid volume determination is a routine part of fetal biophysical profile score testing. The relationship between polyhydramnios and poor perinatal outcome has been previously documented. We have undertaken a retrospective chart review which relates qualitative amniotic fluid volume as determined at the time of last biophysical profile score assessment to perinatal outcome in 7562 referred high-risk obstetric patients. Gross and corrected perinatal mortality in association with normal qualitative amniotic fluid volume ranged from 4.65/1000 and 1.97/1000, respectively, to 32.9/1000 and 4.12/1000 in association with increased qualitative amniotic fluid volume, respectively. The incidences of major congenital anomaly and fetal macrosomia were significantly related to qualitative amniotic fluid volume.

Fetal biophysical profile score and the nonstress test: a comparative trial

In this prospective blind study, 735 patients with high-risk pregnancies referred for antepartum testing of fetal well-being were randomly assigned to either a fetal biophysical profile scoring (375 patients) or a nonstress testing scheme (360 patients). Management was based on the results of antepartum tests, but the method of testing used was not disclosed. Fetal biophysical profile scoring resulted in a significantly higher positive predictive value in regards to low Apgar scores. Sensitivity, specificity, and accuracy, although higher with fetal biophysical profile scoring, did not demonstrate significant differences when compared with the nonstress test. The negative predictive value between the two methods was similar. All major anomalies were detected during ultrasound scanning, whereas none of these anomalies were detected by heart rate testing alone.

Treatment of the fetus in utero: evolving concepts

The rapidly evolving ability to detect the presence of major anomalies in the developing fetus and the emerging prospect of intrauterine treatment of some of these disorders are coupled to create an exciting new frontier in care of the high-risk pregnancy. Preliminary reports suggest that in some highly selected instances perinatal death and morbidity may be prevented by intrauterine surgical procedures. The technical ability to treat the disorder as described is at hand and is unlikely to be the limiting factor in the advance of this area of fetal treatment. However, the very fact that treatment is possible cannot be considered as proof of efficacy. The physician faced with the knowledge that a potentially treatable condition is present in a given fetus may feel the necessity of instituting treatment, but the validity of such an approach is far from established. It is our opinion that efforts should be made to set at the earliest point proper controlled scientific studies from which the benefit, if any, of this surgical approach to fetal disease may be established. Such clinical studies should be conducted in concert with studies in appropriate animal models. It should be noted that fetal surgical treatment is not without potentially lethal fetal and maternal complications. Before such risks, however small, are taken, it seems reasonable to determine the long-term benefits of the surgical procedure. To this end, participation in the International Fetal Surgery Registry is encouraged.

Proton Inelastic Scattering in the Interacting Boson Model: Formalism and Application to the Ge Isotopes

The application of the interacting boson model to the coupled channel description of inelastic proton scattering is studied. The radial shape of the transition potentials is determined by analogy to the usual geometrical models, whereas the reduced matrix elements are calculated from the boson Hamiltonian. The general formalism is applied to scattering from the Ge isotopes. We find a better description for the heavier isotopes in terms of an O(6)-symmetric model than for a vibrational model.

The cost of laboratory technology: a framework for cost management

Laboratory costs at Vancouver General Hospital have been increasing over the past decade. Of the numerous explanations that have been offered for these increases, one contributing factor is the impact of automation and technology. An aggregate measure of laboratory technology was constructed and the net contribution to cost per acute care admission was estimated. Technology has two counteracting effects: It stimulates demand for tests, thus increasing cost per acute care admission, and it increases productivity, thus reducing costs. Effective management may be able to achieve the cost reductions without incurring an increased demand.

The correlation of ultrasonic placental grading and fetal pulmonary maturation in five hundred sixty-three pregnancies

In a previous study, it was suggested that the presence of a grade III placenta correlates 100% with a mature lecithin/sphingomyelin (L/S) ratio and may replace amniocentesis in confirming fetal lung maturity. In this study that hypothesis was tested in 563 pregnancies. All patients underwent amniocentesis and simultaneously had placental grading. The correlations of placental grade with an L/S ration greater than or equal to 2 were: grade 0, 17%; grade I, 68%; grade II, 91%. The correlations of placental grade with the presence of phosphatidylglycerol (PG) were: grade 0, 17; grade 1, 41%; grade II, 79%; grade II, 75%. The false positive rates associated with grade III placenta were, therefore, 7% for mature L/S ratio and 25% for PG present: when combined with a biparietal diameter greater than or equal to 9.0 cm, a grade III placenta incorrectly predicted lung maturity in 8.5%. We conclude that placental grading is not accurate enough to replace amniocentesis as the standard test of fetal pulmonary maturity.

Antepartum determination of fetal health: composite biophysical profile scoring

Antepartum detection, classification, determination of severity, and ultimately treatment of the fetus at risk for death and damage in utero form the very basis of modern perinatal medicine. The availability of accurate methods for assessing the fetus in utero are now becoming available. In extrauterine medicine, assessment of risk is based in part on the patient's activities and response to intrinsic and extrinsic stimuli. In extrauterine medicine, differentiation of normal sleep from coma is made by assessment of multiple biophysical variables and responses. It is most likely that the same principles hold true for differentiating the normal sleeping fetus from the asphyxiated fetus. Biophysical profile scoring offers one method for differentiation. It is likely that incorporation of this principle will improve the quality of perinatal care.

Fetal biophysical profile scoring: a prospective study in 1,184 high-risk patients

The results of a prospective clinical management based on fetal biophysical profile scoring method was evaluated in 1,184 referred high-risk patients. Six perinatal deaths occurred in the study group (perinatal mortality of 5.06 per 1,000); only one fetus suffered unpredictable and unpreventable death (true false negative rate 0.8 per 1,000). In addition, 13 fetuses with major congenital anomalies were detected as a result of ultrasound scanning for fetal biophysical activities. These data suggest that this method can be used effectively to screen and manage a high-risk population.

A simplified intrapartum numerical scoring system. The prediction of high risk in labor

An analysis of 1,994 consecutive parturient women showed that 472 (23%) could be assigned to a high-risk category on the basis of an intrapartum score of greater than or equal to 3. Perinatal mortality, neonatal morbidity, and the rate for operative intervention were all significantly greater for the high-risk group (p < 0.0001). Of the total population, 11% were designated to be at high risk by combining intrapartum and antepartum scores, and 71% of this group had an abnormal intrapartum outcome (p < 0.0001). For this study, 63% of the patients with an abnormal outcome for labor were admitted to the labor floor for 6 hours or longer, and this is an indirect measurement of the potential that exists for optional management. The limitations of intrapartum scoring systems are discussed, particularly with respect to their design, the prediction of preventable deaths, and the category of hospital for which they might prove most useful.

Ovine ceroid-lipofuscinosis: a model of Batten's disease

An inherited neurological disease of sheep was characterized by the intracellular accumulation of autofluorescent lipopigments in neurones and a wide variety of other cells within the body. The staining, fluorescent, ultrastructural and physical characteristics of the storage material were similar to those found in a heterogeneous group of storage diseases of children known as Batten's disease or the ceroid-lipofuscinoses. The ovine disease did not exactly fit any of the main human entities, but had features in common with both the late infantile and juvenile forms. It was concluded that this was a useful model for studying the pathogenesis of this type of storage disease and for therapeutic trials. A flock of sheep is maintained for this purpose.

The role of human placental lactogen assays in antepartum fetal assessment

To determine the role of hPL radioimmunoassays in screening for fetal assessment in normal and hypertensive pregnancies the results of 148 pregnancies were examined by measuring the specificity and sensitivity of the test for prospectively defined fetal conditions. Values of hPL were considered abnormal if they were below the tenth percentile for the range of values derived from pregnancies with a normal fetal outcome ( less than 3.8 microgram/ml). The specificity of the test was 95% but it would have correctly predicted a normal fetal outcome in only 85% of pregnancies. The test varied in its ability to accurately predict abnormal fetal outcome; the sensitivity for the single stillbirth and for cases of fetal jeopardy was 87%, whereas for IUGR the result was 41%. There was a significant difference between hPL values associated with fetal jeopardy and uncomplicated IUGR (p less than 0.01). The frequency of sampling and the application of these results to the prospective screening of normal and hypertensive pregnancies is discussed and it is concluded that hPL assays have a limited but specific role in antepartum evaluation. Screening should be reserved for pregnancies associated with hypertension to exclude the risk of stillbirth and fetal jeopardy occurring specifically in the IUGR fetus.

Perinatal mortality and antepartum risk scoring

A simplified, numerical form for antepartum risk scoring was introduced as a component of the prenatal record for use in all pregancies in a large geographic area under a variety of collection practices. In a population of approximately 1,000,000 with 16,733 deliveries, 19% of the pregnant population scored greater than or equal to 3 and were designated as high risk on the basis of previous pilot studies. This group with high-risk scores had a perinatal mortality rate of 69/1000 compared to the low-risk group with a perinatal mortality of 7/1000 (P = less than 0.0001). The high-risk group accounted for almost 70% of the total perinatal deaths. The implications of being able to predict the statistical likelihood of perinatal deaths are discussed. It is suggested that the risk scoring system has its greatest potential as a screening process and as a method of recording regional statistical trends rather than in dictating the final management of the pregnancy.