Fetal assessment based on fetal biophysical profile scoring. VIII. The incidence of cerebral palsy in tested and untested perinates

OBJECTIVE

The intent of this comparative clinical study was fourfold: (1) to determine the incidence of cerebral palsy in a large obstetric population, (2) to compare the incidence of cerebral palsy in patients at high risk referred for and managed according to the fetal biophysical profile score result with the incidence among unreferred and untested patients, (3) to determine the relationship, if any, between the last fetal biophysical profile score and the incidence of cerebral palsy, and (4) to categorize cases of cerebral palsy according to the clinical parameters and the probable time and nature of the damaging insult.

STUDY DESIGN

In this retrospective 5-year comparative study (1987 to 1991) the incidence of cerebral palsy was determined by analysis of International Classification of Diseases, Ninth Revision, -coded related medical services. The clinical records were then sought and reviewed in index cases and obstetric, neonatal, and postnatal clinical data were abstracted. Cross-correlation with partial registries was done to confirm completeness of capture of index cases. The population of referred high-risk patients who received serial fetal biophysical profile scoring and were managed according to test results was determined by review of a prospective computer-stored database and by review of patient log books. The population of untested patients was calculated as the residual of total cases minus tested cases. The rate of cerebral palsy for all patients and for the tested and untested population was calculated and compared. The tested and untested perinates were compared for birth age, weight, and assigned timing or etiology of cerebral palsy. In the tested population the distribution of test results by last recorded biophysical profile score was determined and the relationship between the last test result and cerebral palsy and predictive accuracy parameters of the fetal biophysical profile score were calculated.

RESULTS

The incidence of cerebral palsy among the 84,947 live births was 3.68 per 1000 live births (313 cases). The rate of cerebral palsy in the 26,290 referred high-risk tested patients was 1.33 per 1000 (35 cases) compared with a rate of 4.74 per 1000 live births in the 58,657 untested mixed low-risk/high-risk patients (278 cases). These differences were highly significant. A significant declining trend in the annual incidence of cerebral palsy was observed in the total population and the untested population, whereas the rate in the tested population remained relatively constant over the 5-year study interval. The differences in the cerebral palsy rate between the tested and untested population were not related to differences in gestational age, birth weight, or assigned timing or etiology category. In the tested population the relationship between the incidence of cerebral palsy and the last test fetal biophysical profile score was inverse, exponential, and highly significant.

CONCLUSIONS

Antepartum assessment by fetal biophysical profile scoring is associated with a significant reduction in the incidence of cerebral palsy compared with untested patients. The relationship between the last test score and the incidence of cerebral palsy is inverse and exponential, suggesting that antenatal asphyxia is an important and potentially avoidable cause of cerebral palsy.

Fetal assessment based on the fetal biophysical profile score: relationship of last BPS result to subsequent cerebral palsy

OBJECTIVE

The prime intent of this study was to determine the relationship if any between the last fetal biophysical profile score and the risk of cerebral palsy at age 3 years. The secondary objective was to examine the clinical characteristics of infants with cerebral palsy whose obstetric management included serial fetal biophysical profile scores.

STUDY DESIGN

The incidence of a high risk pregnant population whose antenatal assessment was by serial fetal biophysical profile scoring was determined by cross-referencing two discrete data bases. The completeness and reliability of the data bases was confirmed by secondary audit. Obstetrical, neonatal and post-natal clinical records of index cases of cerebral palsy were subsequently reviewed, categorized and analyzed.

RESULTS

Fetal biophysical profile scores (BPS) were recorded in 22,336 high risk pregnancies: 27 patients delivered an infant subsequently identified as having cerebral palsy (rate 1.21 per 1000). The relationship between last BPS result and cerebral palsy was inverse, exponential and highly significant (R2 = 0.987; p < 0.001). Affected infants with a last abnormal BPS result were significantly more likely to exhibit fetal distress (88.8%), acidosis (77.7%), and have neonatal seizures (88.8%). Antenatal asphyxia was the apparent cause of cerebral damage in 29.6% of cases.

CONCLUSION

The last fetal biophysical profile score is a predictor of the risk of cerebral palsy.

A computer simulation of the transmission dynamics and the effects of duration of immunity and survival of persistently infected animals on the spread of bovine viral diarrhoea virus in dairy cattle

This paper describes a computer model that mimics the spread of bovine viral diarrhoea virus (BVDV) infection through a closed herd. The model is able to simulate the spread of infection when a persistently infected (PI) animal is introduced into an infection-free herd, and it is used to investigate the role of persistently infected animals, seroconverting animals, loss of PI calves and duration of immunity on the level of infection within the herd. Under typical management conditions one persistently infected animal poses a real threat to a herd, and the prospect of the herd becoming infection free in a 10-year period without intervention is remote. Seroconverting animals are found to be an important source of infection in herds with few immune animals. The increased loss of PI calves is likely to restrict the numbers of PI animals in a herd, and loss of immunity is important since it increases the possibility of a PI calf being born.

The use of a mass-action model to validate the output from a stochastic simulation model of bovine viral diarrhoea virus spread in a closed dairy herd

The spread of bovine virus diarrhoea virus (BVDV) in a closed dairy herd maintained under typical management conditions is studied using two approaches. In the first instance a stochastic computer model is used to simulate the month-to-month changes in the infection status of each animal. These results are contrasted with the results of a mass-action model which uses three differential equations. A comparison of the two approaches indicates that the results are in broad agreement. The stochastic approach has the benefit of providing an estimate of the probability of the infection becoming extinct and the herd becoming BVDV-free for different herd sizes.

Complete resolution of CMV-associated acute hydramnios by single large volume reduction amniocentesis and maternal indomethacin. A case report

Acute hydramnios is a rare complication of pregnancy, usually of idiopathic etiology and associated with a very poor perinatal prognosis. In this single case report, acute hydramnios at 21 weeks' gestation, associated with fetal CMV infection, was treated by a single large volume reduction amniocentesis combined with maternal indomethacin therapy and result in delivery of a near term survivor.

Perinatal outcome in relation to second-stage duration

OBJECTIVE

The second stage of labor has been thought of as a time of particular asphyxial risk for the fetus. This perceived risk has been invoked to justify arbitrary time limits and high rates of operative vaginal delivery. The purpose of this study was to determine whether perinatal outcome worsened as the second stage lengthened.

STUDY DESIGN

Over a 5-year period at one university teaching hospital, 6041 nulliparous women reached the second stage of labor with a live singleton cephalic fetus with birth weight > or = 2500 gm. A retrospective review of perinatal morbidity and mortality was performed and the results related to the duration of the second stage.

RESULTS

The second stage lasted > 3 hours in 11% of nulliparous women and > 5 hours in 2.7%. There were no perinatals death unrelated to anomaly. There was no significant relationship between second-stage duration and low 5-minute Apgar score, neonatal seizures, or admission to the neonatal intensive care unit.

CONCLUSION

Operative intervention in the second stage is not warranted merely because some set number of hours has elapsed.

Expression of reducing sugar accumulation in interspecific somatic hybrids of potato

A somatic hybridisation programme was undertaken to evaluate the expression of reducing sugar accumulation in potato. Interspecific hybrids created between the Solanum tuberosum cultivar Record and the diploid species Solanum phureja were evaluated at the morphological and molecular levels. These analyses indicated that the protoplast regenerants were partial (asymmetric) hybrids which had undergone elimination of S. phureja chromosomes. Tubers of the parents exhibited significant differences for reducing sugar accumulation during cold storage with S. phureja having lower levels of glucose and fructose than Record. The somatic hybrids resembled the S. phureja parent in terms of reducing sugar accumulation demonstrating that low reducing sugar accumulation is dominant to high reducing sugar accumulation in these particular genotypes. These results are discussed in relation to the exploitation of asymmetric hybridisation for the production of potato genotypes for the potato processing industry.

Fetal biophysical profile score. VI. Correlation with antepartum umbilical venous fetal pH

OBJECTIVE

Our objective was to determine the relationship, if any, between the fetal biophysical profile score and antepartum umbilical venous pH.

STUDY DESIGN

This was a prospective observational study conducted concurrently in two centers and involving two discrete high-risk groups of fetuses. Fetal biophysical profile scores were compared with umbilical venous pH values measured in blood obtained by immediate cordocentesis. A total of 493 paired observations of biophysical profile score and pH were made; 104 observations were of fetuses with intrauterine growth retardation and 389 observations were of fetuses with alloimmune anemia.

RESULTS

In both data sets there was a highly significant linear correlation between biophysical profile score and umbilical venous pH. Poor biophysical profile score performance (a score of 0 of 10) was always associated with a pH < 7.20, whereas the pH was always > 7.20 when the biophysical profile score was 10 of 10. Sequenced sensitivity of short-term biophysical variables in the detection of acidemia was observed.

CONCLUSION

The fetal biophysical profile score accurately predicts antepartum umbilical venous pH.

Physicians' perspectives on caring for patients in the United States, Canada, and West Germany

BACKGROUND

The United States is considering enacting a national health plan and global health care budget similar to those in other countries. There are few data on the effects of such policies on physicians and patients.

METHODS

We conducted a telephone survey of 602 physicians in the United States, 507 physicians in Canada, and 519 physicians in the former West Germany from February through May 1991; the response rates were 44 percent, 49 percent, and 41 percent, respectively. Among other topics, the questionnaire included measures of satisfaction with the health care system and with medical practice.

RESULTS

In the United States, 23 percent of the physicians surveyed thought the health care system worked well, as compared with 33 percent in Canada and 48 percent in West Germany. Seventy-three percent of U.S. physicians reported that patients' inability to afford necessary treatment was a serious problem, as compared with 25 percent in Canada and 15 percent in West Germany. Seventy-seven percent of West Germany physicians, 56 percent of Canadian physicians, and 54 percent of U.S. physicians said the shortage of competent nurses was a serious problem. In Canada, 50 percent of the respondents cited the lack of well-equipped medical facilities as a problem, as compared with 14 percent in the United States and 20 percent in West Germany.

CONCLUSIONS

Programs of universal coverage and cost containment necessitate important trade-offs. In Canada and West Germany, physicians do not report serious problems of access to care for the poor and uninsured. In the United States, doctors do not face the limited access to sophisticated forms of medical technology that was reported in Canada or the diminished quality of some services reported in West Germany.

Observations of intrapartum fetal activities

OBJECTIVE

The objective of this observational study was to document the frequency of biophysical activities such as breathing and body movements during spontaneous labor in the low-risk, term fetus.

STUDY DESIGN

The fetuses of truly low-risk patients without medication during labor were observed serially with real-time ultrasonography for fetal breathing or body movements for a maximum scanning time of 1 hour. Fetal breathing movements, hiccups, and fetal body movements were recorded, as were cervical dilatation, status of the fetal membranes, and Apgar scores.

RESULTS

Fetal breathing activity was recorded in 76% of fetuses in early labor and 90% in advanced labor. Fetal body movements were present during 85% of the observations. All babies had 5-minute Apgar scores > 7.

CONCLUSION

Ultrasonographic evaluation of fetal breathing and body movements during spontaneous labor was associated with normal birth outcome in this low-risk population. The clinical utility of this noninvasive method in determining intrapartum fetal health remains to be tested in an unselected population.

Health reform lessons learned from physicians in three nations

To explore the concerns of practicing physicians as a way to inform the health reform debate, the authors conducted a survey of physicians in the United States, Canada, and Germany. Survey results indicate that U.S. physicians are most likely to view affordability as the greatest barrier to access to care for their patients. However, unavailability of services and long waiting times were cited most often by Canadian physicians. German physicians did not cite access problems as frequently as Canadian physicians did; other measures of satisfaction were closer to U.S. levels, suggesting fewer trade-offs if the United States were to adopt aspects of the German health care system.

Maximum possible impact of tocolytics in preventing preterm birth: a retrospective assessment

Although tocolytic drugs are widely used to try to stop preterm labor, their actual contribution to preventing preterm deliveries is unknown. Since tocolytic drugs are not used at the University of Manitoba, it was possible to estimate the proportion of preterm deliveries that might have been eligible for tocolytic drug therapy. Of 364 consecutive preterm deliveries between 24 and 35 weeks, only 9% would have been eligible for, let alone prevented by, tocolytic drug therapy, and even a smaller percentage of babies would actually have benefitted from their use. The use of tocolytic drugs can, at best, benefit only a very small percentage of babies born preterm. Whether the risks of treatment justify this small benefit is arguable.

Must macrosomic fetuses be delivered by a caesarean section? A review of outcome for 786 babies greater than or equal to 4,500 g

Because difficult vaginal delivery is more frequent with macrosomic fetuses, some writers recommend routine Caesarean section for the delivery of fetuses greater than or equal to 4,500 g. The purpose of this study was to evaluate the appropriateness of this recommendation. A retrospective review was undertaken to determine how many fetuses born in our hospital weighing greater than or equal to 4,500 g died or were permanently damaged as a consequence of mechanical difficulties at delivery. During a 10-year period, 590 (75%) of 786 cephalic babies weighing greater than or equal to 4,500 g and alive at the start of labour were born vaginally. No baby died or was permanently damaged as a consequence of mechanical difficulties at delivery. Routine Caesarean section for macrosomic fetuses to prevent death or damage from difficult delivery is not warranted by our results.

Virtual optical nonlinearity in GaAs-AlAs superlattices

We report a full-scale calculation of the third-order susceptibility, X((3)), in GaAs-AlAs superlattices. We present the frequency dependence of X((3)) and find a favorable figure of merit for near-resonant enhancement of X((3)).

Assessment of fetal well-being with ultrasound

The practice of medicine is undergoing marked changes fueled by the infusion of vast amounts of new information concerning the etiology, the progressive pathophysiology, and the complexity of host response to disease states. It is only recently that we have begun to examine the present extent of fetal disease and to determine the characteristics of its advancements. This information now permits new and rational approaches to the management of fetal disease. Clinical significance, both real and potential, of this new wealth of information in reducing perinatal mortality and morbidity is difficult to overestimate. Cumulative experience with fetal biophysical scoring as a method for antepartum fetal risk assessment is now extensive. The cumulative data indicate that the method is sensitive for recognizing both the normal and the compromised fetus. Moreover, the method appears to offer the advantage of grading various degrees of fetal compromise. The additional information gained by real-time ultrasound scanning (gestational age determination, fetal morphometrics, and fetal anomaly screening), although not an integral part of the fetal biophysical profile score, nevertheless remains a critical aspect of antepartum fetal assessment. These data are collected simultaneously with fetal biophysical profile scoring. It is impossible to separate cleanly the advantage of fetal biophysical profile scoring in isolation of this additional information. It would, however, seem that such attempt at separation is artificial because the data in combination provide the key information that the physician needs to guide fetal management. It seems more reasonable to expect that continued modification and improvement of the existing fetal biophysical profile scoring method with inclusion of new testing techniques will be the steps that will occur to improve testing accuracy (Fig. 3). In medical schools in the 1960s, it was generally taught that the concept of "irreducible" perinatal mortality existed and that this figure was usually set at a perinatal mortality of around 8 per 1000. Now in the 1990s that perinatal mortality has already fallen below this irreducible level and continues to fall. We now observe perinatal mortality among tested fetuses of less than 7 per 1000 and corrected perinatal mortalities of less than 2 per 1000. These remarkable results strongly underscore the advantages obtained by ultrasound assessment of the fetus.

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.