The Limits of Electronic Fetal Heart Rate Monitoring in the Prevention of Neonatal Metabolic Acidemia

Abstract

(Abstracted from Am J Obstet Gynecol 2017;216:163.e1–163.e6) Despite advances in technology and training, averting the neurologic injury causing hypoxia-induced fetal metabolic acidemia has not been demonstrated. By examining fetal heart rate tracings of infants with base deficit of more than 12 and base deficit of less than 8, this study seeks to assess the validity of electronic fetal heart rate monitoring (EFM) in preventing adverse metabolic acidemia–related outcomes and validate a fetal heart rate interpretation algorithm, specifically designed to assist with the management of category II fetal heart rate tracings.

The “Fetal Reserve Index”: Re-Engineering the Interpretation and Responses to Fetal Heart Rate Patterns

“…A few months prior to this publication, Clark's group attempted to optimize EFM performance statistics by using internationally recognized experts to perform the interpretations [15]. These authors have been considered key opinion leaders favoring "traditional" interpretations of EFM including metabolic acidosis as the end point required for labor related HIE (rather than injury per se), and espoused the ACOG category system.…”

“…Earlier recognition of high risk would allow fetal therapeutic measures (intrauterine resuscitation [IR] or expedited delivery) to be instituted with the goal of improving the outcome of fetuses at risk for intrapartum neurological injury. Despite previous attempts to develop a risk stratification model to predict or enhance adverse neonatal outcome (low pH, low Apgar score, and NICU admission in labor) [15,26], to our knowledge this combined scheme has not been attempted previously in demonstrably normal fetuses for whom neurological handicap was reasonably demonstrated to have been acquired during labor.…”

“…Reliability has proven elusive, with deficiencies in identifying material endpoints and no apparent improvement in neurological outcome or reduction in allegations of obstetrical negligence [15][16][17][18]. Concomitantly, there are worldwide, controversial efforts to reduce the cesarean section rate in part by increasing the tolerance for increasing lengths of labor and for abnormal FHR patterns [19][20][21].…”

Computer‐based intrapartum fetal monitoring and beyond: A review of the 2nd Workshop on Signal Processing and Monitoring in Labor (October 2017, Oxford, UK)

“…Evidence has been available for nearly half a century that FHR abnormalities are often not related to fetal acidosis 3,4 . As a result, the rate of unnecessary operative deliveries is high 5,6 with adverse implications for this and/or subsequent pregnancies. Furthermore, even experts disagree with each other when interpreting the intrapartum FHR (for example, Chauhan et al 7 ).…”

Cerebral palsy, cesarean sections, and electronic fetal monitoring: All the light we cannot see

“…Lear’s revelation that EFM is based on the wrong physiologic concepts and the wrong interpretative factors of shape and timing, will undoubtedly be relegated to the same place that mainstream medicine has deposited all similar negative EFM revelations—the denialism closet. EFM’s 50-year history is nothing more than one of continuous denial – of science, 1–5 of ethics, 34 of common sense 1–5,7–9,18–20 —by a majority of birth related care givers throughout the industrialized world who continue to use EFM just as it was used a half century ago—to predict and prevent CP with C-sections—despite overwhelming evidence that CP is not primarily caused by asphyxia, 1–9 EFM has a 99% false positive rate, 35 does not predict CP, neonatal neurologic injury of any kind, stillbirths, acidemia, or neonatal encephalopathy, 1–9,36 and as a test for absence of injury EFM is no better than a coin toss. 7 EFM pattern interpretation by so called experts has always been self-contradictory and even today remains subjective, impossible to standardize, poorly reproducible, and the inter-and-intra-observer contradictions remain biased, subjective, and problematic, 33,37,38 and, after 50 years of EFM research and study, meetings, task forces, and widespread clinical use as well as tens of thousands of just in time C-sections based on EFM pattern interpretation, the incidence of CP and other neonatal maladies are the same today as in 1970 when EFM was first used in clinical practice.…”