Vol. 54 No. 5

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Understanding Fetal Monitoring Evidence

When a failure to act on electronic fetal monitoring warning signs results in infant injuries, some medical professionals point to overbroad guidelines to defend their decisions. Learn how research can help rebut this.

Jesse M. Reiter, Emily G. Thomas May 2018

When an infant suffers fetal brain injury due to a lack of oxygen during labor and delivery, medical practitioners often cite electronic fetal monitoring (EFM) guidelines to try to justify their failure to intervene and safely deliver before a fetus suffers brain injury from hypoxia (oxygen deprivation). But medical professionals can and should be held accountable for not responding to EFM tracings that suggest a fetus is at risk. The lack of firm interventional recommendations makes existing guidelines insufficient, and plaintiff attorneys can use research to discover the point at which non-reassuring EFM tracings should have prompted medical professionals to intervene.1

Using EFM during pregnancy, labor, and delivery helps determine whether a fetus is well-oxygenated, reducing the risk of complications related to oxygen deprivation such as neonatal seizures and fetal death.2 It enables medical practitioners to detect fetal acidemia—low blood pH, a marker of oxygen deprivation—earlier and more accurately, allowing them to perform timely ­interventions and deliver the fetus when necessary to prevent injury.3 Numerous studies have corroborated EFM’s value as a useful diagnostic tool4 for preventing fetal asphyxia (oxygen deprivation).5

The Three-Category System

The American College of Obstetricians and Gynecologists (ACOG), the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), and the Society for Maternal-Fetal Medicine developed a three-category system for classifying fetal heart rate (FHR) tracings.6 The system included Category I (FHR tracings considered “normal”), Category II (FHR tracings considered “indeterminate”), and Category III (FHR tracings considered “abnormal”).7

Guidelines were produced for each category, but they do not provide firm recommendations regarding clinical protocols for managing each tracing type—and they do not include specific actionable­ guidelines for intervention and management.

For example, Category I tracings indicate a low level of risk of fetal hypoxia, but a Category III tracing represents a point at which fetal brain injury from oxygen deprivation may have already occurred. Although the guidelines define the characteristics of Category I and Category III ­tracings, Category II is a catch-all for any tracing that is not clearly Category I or III.

Most tracings are classified as Category II, and researchers have found that this group encompasses a wide variety of differences in fetal risk for hypoxic injury, further impeding progress toward developing management guidelines for these tracings.8

Category II Tracings

The standard of care requires doctors to continuously assess the feasibility of safely delivering a healthy baby. But the guidelines do not make recommendations for when to proceed to delivery with a Category II strip,9 and that is the problem with the three-category system. Defendants often claim that the standard of care only requires providers to deliver when fetal monitoring deteriorates to a Category III pattern.

In response, plaintiffs can provide a wealth of medical literature that demonstrates the prudence of intervening to deliver during Category II tracings—before a Category III tracing indicates that fetal brain injury may have already occurred.10

This literature challenges the defense position that continued labor with a Category II tracing is a safe plan when early warning signs are evident.11 There are risks anytime a cesarean section is performed or a baby is delivered prematurely, but these risks may be outweighed by doctors’ ethical and legal obligations to deliver if the tracing indicates a fetus may be at risk of brain damage.

Monitoring for fetal deterioration. According to ACOG, EFM tracings in a patient without complications such as uterine rupture or umbilical cord prolapse should be reviewed approximately every 30 minutes in the first stage of labor and every 15 minutes during the second stage.12 However, research suggests that tracings should be read continuously, allowing medical practitioners to catch the progressive development of hypoxia leading to asphyxia.13

Progressive fetal hypoxia may occur quickly with uterine rupture, umbilical cord prolapse, or placental abruption, or it may occur gradually, accompanied by early changes in FHR. If the EFM ­tracings are not read continuously, medical professionals could overlook changes in FHR, resulting in a missed opportunity for intervention.14

Some fetuses have a predictable progression of deterioration:15

  • FHR decelerations (a gradual decrease in FHR with return to baseline heart rate; these may occur in response to contractions)
  • no accelerations (no increases in FHR above the baseline)
  • significant decelerations (decelerations in FHR that occur spontaneously or before contractions and do not return quickly to baseline)
  • rise in FHR baseline with frequent episodes of tachycardia (fast heart rate) or continuous tachycardia
  • minimal baseline variability (minimal change in FHR from ­baseline, defined as fewer than five beats change from baseline per minute during a 10-minute period)
  • worsening variability
  • absent variability during decelerations
  • prolonged/preterminal bradycardia (abnormally low heart rate compromising oxygen and blood flow). 

When EFM shows the fetus is experiencing one of the above, providers must act to rule out hypoxia and ischemia (inadequate oxygen and blood supply) to help ensure that the fetus is safe. Failing to rule out if the fetus is hypoxic or ischemic is a breach of the standard of care. A Category II tracing indicating hypoxia and ischemia is a warning sign that a fetus is not handling the stress of labor and is likely to deteriorate further as labor progresses.

Early warning signs of hypoxia and ischemia in a Category II tracing are predictive of later acidemia. Therefore, appropriate management of a Category II tracing can require providers to analyze whether a fetus is likely to develop significant acidemia—if so, then they should deliver before the fetus develops damaging degrees of hypoxia and ischemia.16

Researchers stress that the most appropriate time to intervene is when fetuses show signs of tachycardia with decelerations and worsening variability or—if there is no prior tachycardia— when a Category I pattern suddenly develops bradycardia and converts to a Category II or III during the second stage of labor regardless of variability.17

Some fetuses may have fewer oxygen reserves to draw on, which means they may deteriorate more quickly during labor and require more aggressive intervention to prevent injury. This can occur, among other instances, with placental insufficiency, umbilical cord compression, fetal growth restriction, preeclampsia, and chorioamnionitis.18

A number of characteristics—including, among others, tachycardia, bradycardia, late or prolonged decelerations, and terminal decelerations (a decrease in FHR without recovery to the ­baseline heart rate)—are also associated with greater risk of adverse outcomes in the presence of Category II tracings.19

When these characteristics and patterns—which may jeopardize fetal well-being—are evident, providers should proceed to delivery urgently. Evidence that a provider failed to act appropriately can include the delivery of a depressed baby who is acidotic (has a low blood pH), has low Apgar scores, shows signs of seizure activity, or has head imaging after birth consistent with a hypoxic ischemic insult at or near the time of birth.

Building Your Case

As described above, the defense argument that only Category III tracings require intervention and delivery is flawed. The standard of care is to facilitate safe delivery before a baby suffers a hypoxic ischemic injury. When providers see fetuses that present on Category II tracings with the warning signs described above, they should respond to these indications of a lack of oxygen and blood flow and proceed to delivery.


First and foremost, you should be able to read fetal monitor strips.


Be able to interpret EFM. First and foremost, you should be able to read fetal monitor strips. Nurses, nurse midwives, obstetricians, and maternal-fetal doctors read and interpret fetal monitor strips clinically. Obtaining expert reviews from these providers can help you interpret fetal monitoring in your case. There are also many textbooks and nursing training courses that can help you learn how to read tracings.

Understand what information EFM provides. Some defense experts will try to undercut EFM findings by arguing that EFM techniques have a 99 percent false-positive rate. This, however, incorrectly assumes that EFM’s purpose is to predict a single specific outcome. Many of the studies cited to undercut EFM also use measures such as neonatal intensive care unit admissions­ and general neonatal morbidity and mortality that can have causes other than the oxygen deprivation-related injuries that result in abnormal EFM tracings.20

These studies also did not use duration and type of abnormal FHR tracings as common variables, even though certain heart rate patterns—such as absent variability and recurrent late decelerations—are strongly associated with adverse outcomes.21 Defendants also may cite ACOG’s position that use of fetal monitoring has not been proven to decrease cerebral palsy rates.22

Respond by pointing out that all U.S. hospitals use fetal monitoring because it works—as intended—to predict fetal hypoxia and acidemia.23 Since EFM was introduced, survival of neonates has increased at all gestational ages, including among preterm infants.24 Researchers have linked the use of EFM to long-term improvements, including significant decreases in early neonatal and infant mortality.25

Obtain admissions about EFM’s benefits from defense and plaintiff experts. Start with admissions that EFM is used to assess the well-being of the baby; EFM demonstrates the fetus’s ability to recover from hypoxia and the available oxygen reserve; and EFM showing a normal baseline rate with FHR accelerations or moderate variability predicts the absence of fetal acidemia. Bradycardia, absence of variability and accelerations, and the presence of recurrent late or variable decelerations may predict current or impending fetal asphyxia.

When the defense points to the three-category system and its imprecise guidelines, respond by asking questions such as: “Despite ominous fetal tracing findings that predict fetal acidemia, you felt that waiting to deliver was a safe plan to deliver a healthy baby?”

Clarify the existing limitations. Familiarize yourself with criticisms of the three-category system26 and of the existence of proposed alternative models that attempt to address these inadequacies and recommend specific medical interventions.27 Research has shown that in addition to being ­overbroad, existing guidelines are inadequate because they fail to consider other factors that are predictive of fetal acidemia, such as total deceleration.28

Be prepared to have obstetric experts on both sides highlight problems with the three-category system in depositions and trial testimony. Your arguments should emphasize how the standard of care requires providers to ensure a safe delivery that protects the health and well-being of mother and baby. Prepare your tracing evidence to combat any defense arguments that providers could watch and wait rather than intervene.

Intervention and delivery must occur before fetal deterioration can lead to severe injury or death. Medical providers who fail to act should not be able to hide behind inadequate ­guidelines.


Jesse M. Reiter is the founder and Emily G. Thomas is an attorney at Reiter & Walsh in ­Bloomfield Hills, Mich. They can be reached at jreiter@abclawcenters.com and ethomas@abclawcenters.com.


Notes

  1. Non-reassuring EFM tracings suggest that the fetus is not getting enough oxygen.
  2. ACOG Practice Bulletin No. 70: Intrapartum Fetal Heart Rate Monitoring, 106 Obstetrics & Gynecology 1453 (2005); see also ACOG Practice Bulletin No. 106: Intrapartum Fetal Heart Rate Monitoring: Nomenclature, Interpretation, and General Management Principles, Am. Coll. of Obstetricians & Gynecologists (July 2009), https://tinyurl.com/y9yofvg3
  3. See Han-Yang Chen et al., Electronic Fetal Heart Rate Monitoring and Its Relationship to Neonatal and Infant Mortality in the United States, 204 Am. J. Obstetrics & Gynecology 491.e1 (2011).
  4. EFM is not a predictive mechanism for a specific diagnosis. See Håkan Norén et al., Fetal Electrocardiography in Labor and Neonatal Outcome: Data from the Swedish Randomized Controlled Trial on Intrapartum Fetal Monitoring, 188 Am. J. Obstetrics & Gynecology 183 (2003).
  5. See Mariarosaria Di Tommaso et al., Comparison of Five Classification Systems for Interpreting Electronic Fetal Monitoring in Predicting Neonatal Status at Birth, 26 J. Maternal-Fetal & Neonatal Med. 487 (2013); see also James A. Low et al., The Prediction and Prevention of Intrapartum Fetal Asphyxia in Preterm Pregnancies, 186 Am. J. Obstetrics & Gynecology 279 (2002). 
  6. Alternative systems addressing inadequacies in the three-category system have been proposed. See Julian T. Parer & Tomoaki Ikeda, A Framework for Standardized Management of Intrapartum Fetal Heart Rate Patterns, 197 Am. J. Obstetrics & Gynecology 26.e1 (2007), http://www.ajog.org/article/S0002-9378(07)00404-8/pdf; see also Steven L. Clark et al., Intrapartum Management of Category II Fetal Heart Rate Tracings: Towards Standardization of Care, 209 Am. J. Obstetrics & Gynecology 89 (2013); Jaclyn Coletta et al., The 5-Tier System of Assessing Fetal Heart Rate Tracings Is Superior to the 3-Tier System in Identifying Fetal Acidemia, 206 Am. J. Obstetrics & Gynecology 226.e1 (2012); Atsuko Sadaka et al., Observation on Validity of the Five-Tier System for Fetal Heart Rate Pattern Interpretation Proposed by Japan Society of Obstetricians and Gynecologists, 24 J. Maternal-Fetal & Neonatal Med. 1465 (2011), https://tinyurl.com/yazltbuc; Emanuele Soncini et al., Intrapartum Fetal Heart Rate Monitoring: Evaluation of a Standardized System of Interpretation for Prediction of Metabolic Acidosis at Delivery and Neonatal Neurological Morbidity, 27 J. Maternal-Fetal & Neonatal Med. 1465 (2013).
  7. See George A. Macones et al., The 2008 National Institute of Child Health and Human Development Workshop Report on Electronic Fetal Monitoring: Update on Definitions, Interpretation, and Research Guidelines, Am. Coll. of Obstetricians and Gynecologists (2008), https://tinyurl.com/y77jfem3
  8. See Julian Parer et al., Current Commentary: The 2008 National Institute of Child Health and Human Development Report on Fetal Heart Rate Monitoring, 114 Obstetrics & Gynecology 136 (2009).
  9. See Macones, supra note 7. 
  10. See Michelle Murray et al., On NIH Workshop Report, 38 J. Obstetrics Gynecology & Neonatal Nursing 4 (2009), https://tinyurl.com/ybuhnrxb.
  11. See Clark, supra note 6.
  12. ACOG Practice Bulletin No. 106, supra note 1.
  13. See Low, supra note 5.
  14. See Anthony M. Vintzileos & John C. Smulian, Decelerations, Tachycardia, and Decreased Variability: Have We Overlooked the Significance of Longitudinal Fetal Heart Rate Changes for Detecting Intrapartum Fetal Hypoxia?, 215 Am. J. Obstetrics & Gynecology 261 (2016).
  15. See id. 
  16. See id. 
  17. See id. 
  18. See Yinka Oyelese, Operative Obstetrics: Intrapartum Fetal Monitoring 223–39 (Joseph J. Apuzzio et al. eds., CRC Press, 3d ed. 2006). For more explanation of these pregnancy complications, see Medical Encyclopedia, U.S. Nat’l Library of Med. (2018), https://medlineplus.gov/encyclopedia.html.
  19. See Joel D. Larma et al., Intrapartum Electronic Fetal Heart Rate Monitoring and the Identification of Metabolic Acidosis and Hypoxic-Ischemic Encephalopathy, 197 Am. J. Obstetrics & Gynecology 301.e1 (2007); see also S. K. Agrawal et al., Intrapartum Computerized Fetal Heart Rate Parameters and Metabolic Acidosis at Birth, 102 Obstetrics & Gynecology 731 (2003); L.C. Gilstrap III et al., Second-Stage Fetal Heart Rate Abnormalities and Type of Neonatal Acidemia, 70 Obstetrics & Gynecology 191 (1987); Hiroshi Sameshima et al., Unselected Low-Risk Pregnancies and the Effect of Continuous Intrapartum Fetal Heart Rate Monitoring on Umbilical Blood Gases and Cerebral Palsy, 190 Am. J. Obstetrics & Gynecology 118 (2004); Keith P. Williams & France Galerneau, Fetal Heart Rate Parameters Predictive of Neonatal Outcome in the Presence of a Prolonged Deceleration, 100 Obstetrics & Gynecology 951 (2002); Keith P. Williams & France Galerneau, Intrapartum Fetal Heart Rate Patterns in the Prediction of Neonatal Acidemia, 188 Am. J. Obstetrics & Gynecology 820 (2003); Alison Cahill et al., What Intrapartum Electronic Fetal Monitoring (EFM) Patterns Are Associated With Respiratory Morbidity in Term Infants?, 2010 Am. J. Obstetrics & Gynecology S116 (2014); see also Alison G. Cahill et al., Terminal Fetal Heart Decelerations and Neonatal Outcomes, 122 Obstetrics & Gynecology 1070 (2013). 
  20. See, e.g., Lisa Heelan, Fetal Monitoring: Creating a Culture of Safety with Informed Choice, 22 J. Perinatal Educ. 156–65 (2013).
  21. See Am. Coll. Obstetricians & Gynecologists, Task Force on Neonatal Encephalopathy. Neonatal Encephalopathy and Neurologic Outcome (2d ed. 2014); see also Max Wiznitzer, Electronic Fetal Monitoring: Are We Asking the Correct Questions?, 32 J. Child Neurology 344 (2016).
  22. ACOG Practice Bulletin No. 106, supra note 1.
  23. See, e.g., Low, supra note 5; Macones, supra note 7; Parer, supra note 6. 
  24. See Han-Yang Chen et al., Electronic Fetal Heart Rate Monitoring and Its Relationship to Neonatal and Infant Mortality in the United States, 204 Am. J. Obstetrics & Gynecology 491.e1 (2011).
  25. See id
  26. See, e.g., Clark, supra note 6, Coletta supra note 6; Sadaka, supra note 6. 
  27. See, e.g., Parer, supra note 6.
  28. See Alison G. Cahill & Janine Spain., Intrapartum Fetal Monitoring, 58 Clinical Obstetrics & Gynecology 263 (2015).