Effects of electronic fetal-heart-rate monitoring, as compared with periodic auscultation, on the neurologic development of premature infants

Monitoring the fetus in labor: evidence to support the methods

Electronic fetal monitoring (EFM) was implemented across the United States in the 1970s. By 1998, it was used in 84% of all U.S. births, regardless of whether the primary caregiver was a physician or a midwife. Numerous randomized trials have agreed that continuous EFM in labor increases the operative delivery rate, without clear benefit to the baby. Intermittent auscultation (IA) is safe and effective in low-risk pregnancies and may play a role in helping birth remain normal. Clinicians and educators are encouraged to reconsider the use of IA in the care of healthy childbearing women.

Historical controversy in health technology assessment: the case of electronic fetal monitoring

Electronic fetal monitoring (EFM) was introduced in the late 1950s as an alternative to traditional auscultation by stethoscope or fetoscope in the management of labor and delivery. The new technology was seen as a valuable tool in the prevention of cerebral palsy and other adverse fetal outcomes and diffused rapidly into clinical practice. In the late 1970s, some scepticism began to be voiced about the evidence for the effectiveness of EFM. The authors published a systematic review of the evidence in 1979 that concluded that there was insufficient evidence for the effectiveness of the routine use of EFM and a clear rise in the cesarean delivery rate associated with its use. The analysis was based on a thorough review of approximately 600 books and articles, but focused heavily on the evidence of four randomized clinical trials (RCTs) that had been published. An economic analysis further underscored the importance of this issue. The report was met with harsh ad hominem criticism from clinicians both in public venues and in the medical literature. Subsequently, additional RCTs were conducted and other analyzes were published, and in 1987 the American College of Obstetricians and Gynecologists recommended that auscultation was an acceptable alternative to EFM in routine labor and delivery. Yet, today EFM continues to be the standard of practice, used in 80% of labors in this country. The most important conclusion drawn from this experience is the need to evaluate new technologies before their widespread diffusion into clinical practice.

Measuring outcomes of midwifery care: development of an instrument to assess optimality

Research on the outcomes of midwifery care is hampered by the lack of appropriate instruments that measure both process and outcomes of care in lower risk women. This article describes an effort to adapt an existing measurement instrument focused on the optimal outcomes of care (The Optimality Index-US) to reflect the contemporary style of U.S.-based nurse-midwifery practice. Evidence for content validity of the instrument was derived from literature reports of randomized clinical trials, synthetic reviews, and the clinical consensus of professional reviewers. Eleven perinatal health professionals and consumers, representing disciplines of obstetrics and gynecology, midwifery, epidemiology, and neonatology reviewed the instrument. The instrument was then applied to an existing data set of women who intended to give birth at home (N = 1,286 women) to determine its utility in measuring events in the process and outcome of perinatal health care as managed by nurse-midwives. Results suggest that the tool holds promise for use in outcomes studies of U.S. perinatal care. Further testing of the instrument among diverse multicultural population groups, with various providers, and in diverse birth settings is warranted.

Intermittent auscultation of the fetal heart rate: a review of general principles

Multiple randomized clinical trials have been unsuccessful in providing evidence of efficacy of electronic fetal monitoring; thus, there is renewed interest in intermittent auscultation during labor for women with low-risk pregnancies. Auscultation must be used with palpation or external or internal electronic monitoring of uterine contractions. Auscultation and palpation require education, experience, and competency validation at regular intervals. Institutional policies and standards of care are mandatory for intermittent auscultation. Concerns exist regarding the personnel costs for auscultation; however, these costs may ultimately be shown to be offset by significant benefits in improved outcomes and patient satisfaction.

Defensive medicine during hospital obstetrical care: a byproduct of the technological age

This paper presents an alternative perspective on defensive medicine. Defensive medicine is usually understood as arising from the effect of law on medicine through fear of litigation. Of equal significance, however, is the complementary influence of medicine on law through technological innovation, and, more importantly, the way that medicine and law develop dialectically. Each shapes the other in establishing the standards of care central to both clinical medicine and to actual or potential legal action. Excessive testing owing to fear of litigation indicates that defensive medicine is being practised in a particular setting, but it does not explain why this is so. To understand why defensive medicine occurs and why it is so troubling to clinicians requires an understanding, not only of medical and legal developments, but of a political-economic system and the beliefs and values of a society. Defensive medicine is discussed in relation to hospital obstetrical scenarios commonly associated with fear of litigation: fetal oxygen deprivation ("distress"), which is detected using an electronic fetal monitor, and prolonged labor, known as "dystocia". The material presented is taken from a medical anthropological study of obstetrical care in rural British Columbia, Canada. Litigation fears are shown to result less from rare, albeit often devastating, allegations of malpractice than from doctors adopting a role as "fetal champions", together with the introduction of electronic monitoring technology. The paper concludes by asserting that, rather than being in an adversarial relationship, medical practice and associated litigation primarily work together to reinforce each other, and the social conditions in which defensive medicine occurs.

Can neurological injury be timed?

Our knowledge about the cause of cerebral palsy continues to expand and prenatal events are thought to play an important role. This article reviews laboratory tests, imaging studies and pathologic findings that have been used to identify the timing of neurological injury. Limitations exist for all modalities, however, imaging studies, electroencephalograms and pathologic examination provide the most useful information. Improvements in our ability to time neurological injury will better direct our efforts to prevent cerebral palsy.

Fetal heart rate monitoring: is it salvageable?

Fetal heart rate monitoring was introduced in the 1960s. After a number of randomized controlled trials in the mid 1980s, doubt arose regarding the efficacy of fetal heart rate monitoring in improving fetal outcome. The potential reasons why fetal heart rate monitoring has not been shown to be efficacious are (1) use of an outcome measure that is not related to variant fetal heart rate monitoring patterns, (2) lack of standardized interpretation of fetal heart rate patterns, (3) disagreement regarding algorithms for intervention of specific fetal heart rate patterns, and (4) the inability to demonstrate the reliability, validity, and ability of fetal heart rate monitoring to allow timely intervention. A recent National Institutes of Health committee proposed detailed, quantitative, standardized definitions of fetal heart rate patterns, which can serve as a basis for determining whether fetal heart rate monitoring is reliable and valid. In this article we examine reasons why fetal heart rate monitoring did not live up to its original expectations and why the randomized controlled trials did not demonstrate efficacy, and we make suggestions for determining whether electronic fetal heart rate monitoring should be abandoned.

Electronic fetal heart rate monitoring: early neonatal outcomes associated with normal rate, fetal stress, and fetal distress

OBJECTIVE

The purpose of this study was to test the ability of a clearly defined classification system for electronic fetal heart rate monitoring to predict early neonatal outcome.

STUDY DESIGN

All labors of women with singleton pregnancies > or = 32 weeks' gestation electronically monitored at 2 institutions were examined. Tracings in the final hour before delivery were defined as normal, fetal stress, or fetal distress. After delivery, Apgar scores, cord blood gas values, and admission to the neonatal intensive care unit were examined as measures of early neonatal outcome.

RESULTS

Among the 898 patients who qualified for study, 627 (70%) had tracings classified as normal, 263 (29%) had tracings classified as fetal stress, and 8 (1%) had tracings classified as fetal distress. There was a significant worsening of neonatal outcome across these 3 groups with regard to depressed Apgar scores 1 minute (5.1%, 18.3%, and 75.0%; P <.05), depressed Apgar scores at 5 minutes (1.0%, 3.8%, and 37.5%; P <.05), and admission to the neonatal intensive care unit (5.6%, 10.6%, and 37.5%; P <.05). There was also a progressive worsening of cord blood pH (7.27 +/- 0.06, 7.21 +/- 0.08, and 7.06 +/- 0.14; P <.05), a progressive increase in PCO (2) (53.39 +/- 8.34 mm Hg, 58.51 +/- 10.55 mm Hg, and 78.31 +/- 20.35 mm Hg; P <.05), and a progressive decline in base excess (-3.18 +/- 2.02 mEq/L, -5. 11 +/- 3.11 mEq/L, and -9.07 +/- 4.59 mEq/L; P <.05).

CONCLUSION

This simple classification system for interpreting fetal heart rate tracings accurately predicts normal outcomes for fetuses as well discriminating fetuses in true distress. Further, it identifies an intermediate group of fetuses with a condition labeled fetal stress who might benefit from additional evaluation and possibly from expeditious delivery.

Continuous electronic heart rate monitoring for fetal assessment during labor

BACKGROUND

Electronic fetal monitoring (EFM) has been widely adopted. There is debate about its overall effectiveness as well as the relative merits of routine application versus use for high-risk pregnancies only.

OBJECTIVES

The objective of this review was to assess the effects of routine continuous electronic fetal monitoring during labour compared with intermittent auscultation.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register, Medline (1966 to 1994), and reference list of relevant articles. We also contacted experts in the field.

SELECTION CRITERIA

Randomised trials comparing routine continuous electronic fetal monitoring with intermittent auscultation.

DATA COLLECTION AND ANALYSIS

Data were extracted by one reviewer, and their accuracy was confirmed independently by a second person. A single reviewer assessed study quality based on criteria developed by others for randomised controlled trials. Data reported from similar studies were used to calculate a combined risk estimate for each of eight outcomes.

MAIN RESULTS

Nine studies involving 18,561 women and their 18,695 infants were included. The trials were of variable quality. A statistically significant decrease was associated with routine continuous EFM for neonatal seizures (relative risk (RR) = 0. 51, confidence interval (CI) = 0.32,0.82). The protective effect for neonatal seizures was only evident in studies with high-quality scores. No significant differences were observed in 1-minute Apgar scores below 4, 1-minute Apgar scores below 7, rate of admissions to neonatal intensive care units, and perinatal death. An increase associated with the use of EFM was observed in the rate of cesarean delivery (RR = 1.41, CI = 1.23,1.61) and operative vaginal delivery (RR = 1.20, CI = 1.11,1.30).

REVIEWER'S CONCLUSIONS

The only clinically significant benefit from the use of routine continuous EFM was in the reduction of neonatal seizures. In view of the increase in cesarean and operative vaginal deliveries, the long-term benefit of this reduction must be evaluated in the decision reached jointly by the pregnant woman and her clinician to use continuous EFM or intermittent auscultation during labor.

New developments in fetal monitoring for the anesthesiologist

Assessing fetal wellbeing has evolved from the ancient awareness of 'quickening' to a vast array of biophysical, imaging and biochemical methods. Because the results of these tests influence the urgency of fetal delivery and sometimes the choice of maternal anesthetic technique, it is important for anesthesiologists to understand the fundamentals of fetal monitoring and the changing face of new developments in this field. Noteworthy publications from the past year on this topic include new guidelines for the interpretation of fetal heart monitoring, advances in intrapartum fetal pulse oximetry, thresholds of acidosis associated with fetal injury, and efforts to decrease cerebral palsy through better antenatal biophysical testing.

Issues in promoting health

Policymakers in many countries seek to contain health care costs over the long range by promoting health and more effective health behavior. Such efforts can be directed at entire populations, at members of a health plan, at defined risk groups or single individuals at risk. Many health risks are associated with socio-economic status and social inequalities but these are often difficult to address because of social and political conflicts. Health, also, is often a product of culture and other social circumstances. Health may be promoted through non-health interventions or through more targeted health efforts seeking to effect behavior change. Preventive screening is of growing importance but such efforts often out-pace evidence of efficacy or cost-effectiveness. Many opportunities exist to build on new clinician-patient partnerships to make patients better informed and to effect positive health behavior. New technologies, and particularly the internet, offer new ways to promote health and more constructive illness behaviors.

The incidence of abnormal findings from intrapartum cardiotocogram monitoring in term and preterm labours

A retrospective analysis of 514 consecutive labours delivering 530 babies over a period of 18 months was conducted by a high-risk pregnancy team in a tertiary teaching unit to compare the incidence of abnormal findings from intrapartum monitoring between labours occurring before and at or after 34 weeks' gestation. Those delivered by elective Caesarean section, or Caesarean section at the onset of labour because of contraindications to labour and vaginal delivery, and those with congenitally malformed fetuses were excluded. Tracings were scored using the FIGO 1987 guidelines. Seventy-four labours and 83 babies delivered before 34 weeks, and 440 labours and 447 babies delivered after 34 weeks in the study. There was a slightly higher incidence of suspicious CTG tracings (33.7% versus 19.6%, OR 2.66, 95% CI 1.6-4.4) in the preterm group, due mainly to decreased baseline variability (p<0.001, OR 3.57, 95% CI 1.8-6.9), but the incidence of other pathological patterns did not differ. Using the same set of criteria for interpretation, there was a higher incidence of abnormalities from continuous cardiotocogram monitoring in the preterm group compared to term labours, but the intervention rate for fetal distress was not significantly increased. Appropriate interpretative criteria for intrapartum monitoring of preterm labours should be devised.

Stochastic technology, production organization and costs

Using a model including patients, physicians, insurers and uncertain diagnostic technology, the optimal cesarean rate is derived from preferences, technology and the incidence rate, when the choice of insured patients is constrained only by technology. Uncertain diagnosis produces unnecessary cesareans and unsafe vaginal births. Technical progress can lead to more cesareans and higher costs. Joint production of goods and bads and collective payments require incentive compatible pricing schemes, different from RBRVS. Equilibrium outcomes of HMOs and free-for-service organizations are identical. However, implementable incentive schemes involve additional costs. Efficiency requires insurers, and not providers, to be liable for malpractice claims.

Inappropriate use of new technology: impact on women's health

While medical technology is very useful we need to be aware of its inappropriate use. Examples are given, such as: continuous vs. intermittent electronic fetal monitoring; widespread use of magnetic resonance image technology where simple methods could be as effective; laparoscopically assisted vaginal hysterectomies replacing simple vaginal hysterectomies and increasing the cost; ultrasound to provide the first pictures of the baby or to detect female fetuses for female feticide; use of technology for defensive medicine rather than using it for the patient's welfare, and pecuniary indications. Woe betide the doctor who does not make enough money--he may find that his contract is not renewed. We need to empower patients with information, so that they can judge the technology and its appropriateness as it relates to them. Opinion programs have helped to curb the misuse of unnecessary surgery, and audit and peer review programs also provide a check on the misuse of technology. The provision of consensus statements, e.g. by the National Institutes of Health, USA, have helped to clarify issues and to guide doctors as to the appropriateness of the newer technologies, and practice guidelines formulated by experts are also very helpful. We need to teach medical students and residents how to be critical, how to evaluate claims and study the literature, so that they are not hoodwinked by 'authority' or misled by manufacturer's claims.

Fetal oximetry monitoring: a new wonder or another mirage?

This review provides recent data and clinical opinions on a new technology in assessing fetal well-being during labor, the fetal pulse oximeter. Fetal pulse oximetry is potentially superior to electronic fetal heart rate monitoring because it allows direct assessment of both fetal oxygen status and fetal tissue perfusion. Several studies during recent years have demonstrated that fetal pulse oximetry during labor is feasible and accurate. On the other hand, these very same studies have demonstrated a few potential disadvantages and limitations of fetal oximetry. The main limitation seems to be a wide range of normal values. The correlation of fetal oximetry during labor with perinatal outcome and long-term newborn outcome has not yet been determined. In summary, fetal pulse oximetry during labor merits further randomized prospective studies, especially with regard to improvement of perinatal outcome.

Monitoring technology and the clinical perspective

Currently available technology requires a new look to reduce intervention as well as to improve the detection of the truly at-risk fetus. Iatrogenic causes of so-called fetal distress, in particular the administration of uterotonics without due attention to avoiding hyperstimulation, predominate as a reason for intervention. There needs to be a better definition of the starting point, i.e assessment of the fetal condition and identification of any risk factors, such as oligohydramnios and growth retardation, that might diminish fetal reserve. This will allow 'customization' of surveillance and management according to the needs of each individual fetus. There also needs to be better training and better agreement about the end-point of monitoring. For prospective surveillance, the aim is to avoid rather than to identify damage, and the definition of the appropriate point for intervention needs to come from better consensus on what is and what is not acceptable management based on current knowledge. New technology holds the promise that it can give trended information during labour, allow early recognition of problems and reduce unnecessary intervention. However, there is a need to ensure reliability and reproducibility of the readings before a new method is released. Co-operation with industry is essential, but the roles need to be well defined and the ultimate responsibility for establishing the role of a new technique has to come from the clinicians involved in intrapartum care.

On intrapartum fetal monitoring

The currently advised conduct for intrapartum surveillance of the fetus is either intermittent auscultation of continuous electronic monitoring, depending on the physician's preference. This applies to all, normal or high-risk, conditions. The bases for this recommendation, a number of controlled studies comparing the two methods, showed no better neonatal outcomes and increased cesarean section rates with electronic fetal monitoring. A review of the works pertaining to fetal development of cardiovascular and central nervous systems and their response to various pathophysiologic conditions (in animals and humans) was carried out in an effort to find an explanation for this apparently uncongruous position. It was found that fetal responses to seemingly comparable conditions are radically different depending on age of gestation. Many authors have pointed this out for the human fetus. However, for interpretation of electronic fetal monitoring in labor, various standard, nondescriptive, confusing words are used to imply the need for rapid intervention. The complete lack of uniform interpretation has been shown in studies comparing interobserver and intraobserver variations. This may be the consequence of poor or superficial teaching of a tool that requires much study and hard work for useful application. The inescapable conclusion is unpleasant but inevitable: to use electronic fetal monitoring properly it is necessary to start a new learning of the physiology of the fetus, its changing evolution as pregnancy advances, its different responses under stress or distress, and the various ways these are represented in electronic fetal monitoring tracings. These efforts take dedication and time spent in labor suites collating tracings with neonatal condition. Only by doing this will it be possible to assist the laboring patients with a useful tool that, so far, has not been adequately applied because of insufficient understanding.

Evaluation of a fetal monitoring education program

OBJECTIVE

To evaluate the effectiveness of a fetal monitoring education program in increasing nurses' knowledge and clinical skills.

DESIGN

Multicenter randomized control trial.

SETTING

Twelve hospitals in eastern Ontario, Canada.

PARTICIPANTS

One hundred nine volunteer registered nurses randomly assigned, within each hospital, to an experimental (n = 47) or control (n = 62) group. Ninety-six nurses (40 in the experimental group and 56 in the control group) completed the 6-month follow-up (88% retention).

INTERVENTIONS

The experimental group participated in a 1-day fetal monitoring workshop and a review session 6 months later.

MAIN OUTCOME MEASURES

Performance on a 45-item knowledge test and a 25-item skills checklist. The passing score was at least 75% correct on each test.

RESULTS

The percentage of nurses in the experimental group passing both the knowledge and the clinical skills tests after the workshop was significantly higher (p < 0.01) than that of the nurses in the control group: 68.1% versus 6.5%, respectively. A large difference between the groups remained at the 6-month follow-up (experimental, 45%; control, 6.5%). The performance of the nurses in the experimental group improved to an 85% pass rate after they attended the 6-month review session.

CONCLUSION

This comprehensive, research-based program is effective in increasing fetal monitoring knowledge and clinical skills.

Anthropology, clinical pathology and the electronic fetal monitor: lessons from the heart

Clinical pathology, the social process of applying disease categories and managing disease processes, is defined and its anthropological study described using examples from a study of Electronic Fetal Monitor (EFM) use during hospital obstetrical care in a rural Canadian village. Anthropological work on clinical pathology is shown to have helped doctors and nurses in this village to better understand both the cultural contingencies of their basic science knowledge and the historical contingencies of its application to the care of women during pregnancy and birth. It is argued that cultural anthropologists should study diagnostic and treatment activities, especially those involving sophisticated technology; their methods and theories make them ideally suited to this task.

Why has conventional intrapartum cardiotocography not given the expected results?

It is probable that conventional electronic fetal monitoring (EFM) has reduced the intrapartum death rate, but the expected dramatic reduction in neurological handicap has not occurred. There are two reasons for this: the majority of infants, who develop neurological problems have been harmed before the onset of labor, and the method of EFM has been more difficult to use in daily routine than expected. However, EFM is the best method we have to monitor high risk cases and the results can be improved by better training of the staff.

Syndromes in twins

There is a higher incidence of perinatal mortality and morbidity in twins than in singleton pregnancies. The main reason for this increase is the higher incidence of preterm delivery in twins. There are special conditions unique to twins that also contribute to this increased perinatal morbidity and mortality. These conditions include monoamniotic twins, congenital anomalies unique to twins, ie, conjoined twins and acardia, intrauterine fetal demise, and twin-to-twin transfusion syndrome. These conditions are the subject of this review. The prenatal determination of chorionicity is discussed first, because this assessment is key to the diagnosis and management of many of these conditions.

Asphyxia

The prevention of fetal asphyxia or hypoxia starts with prepregnancy counseling and continues with careful antenatal care and intrapartum fetal surveillance. Further progress in eliminating antepartum and intrapartum deaths will only be made when it is accepted that, even with intense investigation by detailed autopsy, the cause of many deaths remains unknown. Many of these deaths may be ascribed to hypoxia. In the future, with more detailed non-invasive probing with CAT scanning and magnetic resonance imaging, other causes may be determined. The mother at risk of hypoxia requires specialized attention. Such mothers will include those with severe cardiac, pulmonary or circulatory problems. Others will be those with endocrine problems, such as diabetes or thyroid dysfunction. At present, failure of fetal growth is generally ascribed to hypoxia, but undoubtedly, in solution to such problems of possible hypoxia is elective delivery at the appropriate time. What Hensleig said in 1986 (Hensleig et al, 1986) is equally true today: 'Preventative programmes will remain unsuccessful until the causation of cerebral palsy is more understood. What we are presently lacking is an understanding of the underlying conditions responsible for brain injury when asphyxia occurs despite our best efforts. While we have learned much about the causation and prevention of perinatal mortality very little has been established about the causation and prevention of cerebral palsy'. Finally, Hall (1989), in a review of birth asphyxia and cerebral palsy, concludes the following five points. 1. The incidence of cerebral palsy is not falling despite improved obstetrics. 2. The cause of more than 90% of cases of cerebral palsy remains unknown. 3. Asphyxia is hard to define and measure and is rarely the cause of cerebral palsy. 4. Hypoxic ischaemic encephalopathy is the most reliable indicator of asphyxia. 5. Neither traditional clinical signs nor electronic monitoring allow reliable recognition of asphyxia.

How useful is intrapartum electronic fetal heart rate monitoring?

It is essential for an obstetric anesthesiologist to be aware of the fetal status before undertaking care of the laboring mother. In the last 20 years electronic fetal monitoring has been the most widely used technique of evaluating the fetus in labor. Recently however, the ability to predict or improve fetal outcome using traditional interpretation has been questioned. This review presents a summary of the current technology and interpretation of intrapartum electronic fetal monitoring, as well as a discussion of its limitations and some of the developments in this field which may help improve the accuracy of fetal assessment. The new developments in fetal monitoring discussed in this article are computerized assessment of fetal heart tracings, heart rate variability analysis, fetal electrocardiogram waveform analysis, abdominal detection of fetal ECG, fetal scalp oxygen saturation, fetal pH sampling and transcutaneous oxygen and carbon dioxide measurement.

Do concepts of causes and prevention of cerebral palsy require revision?

OBJECTIVE

My purpose was to explore the criteria of The American College of Obstetricians and Gynecologists (Technical Bulletin No. 163) for perinatal asphyxia to be linked to subsequent cerebral palsy.

STUDY DESIGN

Analysis of four cases of intrapartum fetal insults with subsequent cerebral palsy and a literature review are presented.

RESULTS

All of the four cerebral palsy cases had sufficient intrapartum causes of cerebral palsy, yet none fulfilled The American College of Obstetricians and Gynecologists' linkage criteria. Complications in the cerebral palsy cases were as follows: maternal intrapartum cardiac arrest, fetal skull fracture with brain infarct, intrapartum fetal stroke, and a newborn delivered after uterine rupture with only central nervous system defects. There are no well-done laboratory or clinical studies that unequivocally support the "criteria" that umbilical artery pH must be < 7.00 or the requirements of Apgar score < 3, hypoxic-ischemic encephalopathy, and multiple organ dysfunction. Apparent exceptions to these criteria occur.

CONCLUSIONS

The American College of Obstetricians and Gynecologists Technical Bulletin's criteria for cerebral palsy linkage and the role of parturition in cerebral palsy should be reevaluated. A rebirth of obstetric enthusiasm for cerebral palsy research, teaching, and treatment needs to occur.

Perinatal asphyxia: assessing its causal role and timing

Perinatal asphyxia, whether prenatal, intrapartum, or neonatal is thought to be a significant contributor to newborn morbidity and mortality as well as long-term neurological deficits. Development of an intrapartum tool/test that can reliably identify and discriminate between varying degrees of fetal acidemia and suggest whether it is respiratory or metabolic in nature would be highly desirable. This article critically reviews the available experience with the currently available monitoring techniques and the significance of abnormalities of fetal and intrapartum measurements with respect to the predictive value of the observations available to the clinician.

The predictive value of intrapartum fetal heart rate abnormalities in the extremely premature infant

OBJECTIVE

Our purpose was to evaluate the validity of intrapartum fetal heart rate tracings in predicting short- and long-term outcomes of infants delivered between 24 and 26 weeks.

STUDY DESIGN

Fetal heart rate tracings obtained during the last hour before delivery of fetuses delivered at 24 to 26 weeks' gestation were reviewed. Two perinatologists blinded to neonatal outcome evaluated the tracings for the following attributes: baseline rate and variability, presence and severity of decelerations, and overall impression (reassuring, nonreassuring, or ominous). Measured outcomes were cord blood pH; Apgar scores; intraventricular hemorrhage; duration of assisted ventilation; and hospitalization, survival, and developmental status at 1 year.

RESULTS

The fetal heart rate attribute that was found to be predictive of neonatal outcome was the presence of any bradycardia or tachycardia found in any 10-minute window (designated "baseline rate abnormality"). This correlated with neonatal death (p < 0.007). None of the other fetal heart rate attributes were associated with any neonatal outcome. Intraobserver agreement was "fair to good" (kappa 0.5).

CONCLUSION

Fetal baseline rate abnormalities (either tachycardia or bradycardia) were predictive of neonatal death in extremely premature fetuses.

Interobserver variation in the assessment of fetal heart rate recordings

Electronic fetal heart rate monitoring (EFM) has not fulfilled its expectations. To improve its validity various attempts were made to standardize terminology and assessment of fetal heart rate (FHR) recordings. In a multinational study, 21 experienced obstetricians were asked to segment and classify FHR patterns, recorded in 13 obstetric cases. In addition, the referees were asked to give their interpretation of the FHR pattern, to assess the fetal condition and to propose obstetric management. The kappa statistic showed fair agreement among the obstetricians for the classification of accelerations, baseline segments and decelerations. Poor agreement was found when the referees had to classify baseline variability or the type of deceleration. Also, the clinical assessment of fetal condition and proposals for obstetric management showed poor agreement among the referees. We conclude there is still a lack of unequivocal terminology and definitions in the assessment of FHR recordings.

Stuck twin syndrome: outcome in thirty-seven consecutive cases

OBJECTIVE

Our purpose was to further evaluate the role of serial amniocentesis in pregnancies complicated by the "stuck twin" syndrome.

STUDY DESIGN

A cohort of 37 consecutive cases of stuck twin syndrome was followed up from 1986 through 1992. Evaluations included gestational age at diagnosis and at delivery, mean number of amniocenteses, volume of amniotic fluid withdrawn, placentation, perinatal complications, fetal survival, and neonatal follow-up.

RESULTS

Five pregnancies were terminated, five had no intervention, and 27 underwent serial amniocenteses. The mean number of amniocenteses was 3.4 (range 1 to 6), and mean total amniotic fluid volume withdrawn was 5.8 L (range 0.75 to 4.0). In the serial amniocentesis group mean gestational age was 23.1 weeks (range 16 to 30) at diagnosis and 31.5 weeks (range 20 to 38) at delivery. Eighty-two percent had monochorionic placentas, and 36% had marginal or velamentous cord insertions. Infant survival was 39 of 54 (74%) in the serial amniocentesis group compared with four of 10 (40%) in the nonintervention group (relative risk 0.46, 95% confidence interval 0.24 to 0.90).

CONCLUSION

Serial amniocentesis was associated with a 54% reduction in fetal and neonatal death in cases of stuck twin syndrome.

Children and cancer. A perspective from the Cancer Therapy Evaluation Program, National Cancer Institute

The Cancer Therapy Evaluation Program, National Cancer Institute (CTEP, NCI) strongly supports the role of controlled clinical trials in improving the care of children with cancer, and particularly the central role that the pediatric Cooperative Groups play in this process. Trends that threaten the ability to perform these trials include the increasingly limited financial resources available for clinical investigations and the sentiment within some circles that controlled clinical trials may be inappropriate for ethical reasons. The inherent risks of accepting a new therapy without rigorous comparison to existing therapy strongly support the need for randomized trials with adequate accrual to answer important therapeutic questions in a timely and reliable fashion. Retrospective analysis of multiple clinical trials is one method for identifying compelling hypotheses to be tested prospectively. Using this method, we have demonstrated the association between doxorubicin dose intensity and positive response and outcome for patients with Ewing sarcoma and osteosarcoma, thereby providing direction for the selection of important therapeutic questions to be addressed in future clinical trials for these malignancies.

Intrapartum fetal heart rate assessment: monitoring by auscultation or electronic means

OBJECTIVE

Our purpose was to assess the frequency with which auscultation could be used as the primary mode of fetal assessment during labor in a busy labor and delivery suite by means of published criteria.

STUDY DESIGN

During a 3-month period, 862 patients in labor with live fetuses between 24 and 43 weeks of gestation were available for auscultation in the prospective study. Auscultation was initiated during a contraction and extended for 30 seconds after uterine activity ceased. It was repeated every 15 minutes in the first stage and every 5 minutes in the second stage of labor.

RESULTS

In 420 patients this modality was not begun because of inability of the nurses to meet 1:1 staffing requirements. In 19 patients auscultation was not performed because of obesity (12) or patient refusal (7). Of the 423 assessed by auscultation 392 were unable to complete monitoring caused by the frequency requirement (n = 212) or the recording criteria (n = 163). Of the 31 patients where auscultation was successfully completed, there was a 1:1 nurse ratio during the entire labor.

CONCLUSIONS

Auscultation with stringent evaluation and recording frequency is not feasible under normal labor and delivery room conditions unless 1:1 nursing care is always available.

Premature adoption and resolution of medical technology: illustrations from childbirth technology

The first part of this article discusses four forces underlying the emergence, adoption, and routinization of medical technology: key societal values, policies of the federal government, reimbursement policies, and economic incentives. It also addresses a set of impacts resulting from increased reliance on medical technology. The second part of the paper assesses three examples of childbirth technology: electronic fetal monitor, obstetric ultrasound, and cesarean birth. The tendency toward premature and excessive use of technology is especially strong in the area of childbirth and technology.

Fetal heart rate variability and behavioral state: analysis by power spectrum

OBJECTIVE

We attempted to determine the relationship between the fetal heart rate power spectrum and fetal state.

STUDY DESIGN

Interbeat intervals, electrocortical activity, and fetal breathing movements were recorded from five near-term fetal lambs. Interbeat intervals were taken from epochs of low-voltage electrocortical activity with breathing, low-voltage electrocortical activity without breathing, and high-voltage electrocortical activity without breathing. Power spectral techniques were applied to determine the underlying frequencies contributing to fetal heart rate variability. Spectral analysis was also performed on fetal breathing data from three animals.

RESULTS

Significant differences were found between low-voltage electrocortical activity with breathing and high-voltage electrocortical activity without breathing at 0.62 Hz and from 1.09 to 1.56 Hz. There was no clear relationship between the breathing and heart rate spectra.

CONCLUSIONS

Fetal heart rate is mediated by both state and respiratory variables. The respiratory component is not strictly related to respiratory rate.

Identification of neurodevelopmental abnormality at four and eight months by the movement assessment of infants

The predictive validity of infant neuromotor evaluation by the Movement Assessment of Infants (MAI) was investigated in low-birthweight infants. Motor performance at four and eight months was examined in relation to neurodevelopmental outcome at 18 months of age. Correlations were equally strong between total MAI risk scores at four and eight months and performance on the Bayley Scales. Muscle tone observations were more discriminating at four months, and automatic reactions and volitional movement were most predictive at eight months. The MAI was highly sensitive to neurodevelopmental abnormality at four and eight months and more sensitive than the Bayley Motor Scale; both assessment tools had lower specificity at eight months. The high false-positive rate is attributed to transient neuromotor abnormalities and immaturity of motor function in low-birthweight infants with normal outcome.