Re-engineering the interpretation of electronic fetal monitoring to identify reversible risk for cerebral palsy: a case control series

Development, Validation, and Diagnostic Accuracy of the Fetal Lack of Responsiveness Scale for Diagnosis of Severe Perinatal Hypoxia

Background: There are limitations to predicting perinatal asphyxia, as current tools rely almost entirely on fetal cardiotocography (CTG). The fetal lack of responsiveness scale (FLORS) is a new diagnostic alternative based on the physiological phenomena associated with fetal hypoxia. Objectives: The objective of this study was to develop, validate, and assess the diagnostic accuracy of the FLORS for predicting severe perinatal hypoxia (SPH). Study Design: A two-phase retrospective observational cross-sectional analytical study was conducted. Phase 1 involved the formulation and retrospective validation of the FLORS. A total of 366 fetal CTG records were evaluated twice by seven readers. Phase 2 was a collaborative, retrospective, multicenter diagnostic test study that included 37 SPH and 366 non-SPH cases. Results: Phase 1: A numeric, physiology-based scale was developed and refined based on expert opinions. The median time to apply the scale per reading was 38 s. Cronbach's alpha, which is a reliability measure, was significant (p = 0.784). The kappa index for test-retest agreement was moderate to reasonable, with a median value of 0.642. For interobserver agreement, the kappa index per variable was as follows: baseline, 0.669; accelerations, 0.658; variability, 0.467; late/variable decelerations, 0.638; slow response decelerations, 0.617; and trend to change, 0.423. Phase 2, including 37 SPH and 366 non-SPH cases, showed a sensitivity of 62.2% and specificity of 75.4% for the 2-point score, whereas the 3-point score had a sensitivity of 35.1% and specificity of 89.9%. The area under the curve (AUC) was significant at 0.73 (CI 0.645-0.818). Conclusions: FLORS demonstrated significant internal consistency and observer agreement, with a promising sensitivity-specificity balance and significant AUC. Further research is needed to assess its impact on perinatal hypoxia and cesarean delivery.

Etiology and Ontogeny of Cerebral Palsy: Implications for Practice and Research

Cerebral palsy (CP) has been recognized as a group of neurologic disorders with varying etiologies and ontogenies. While a percentage of CP cases arises during labor, the expanded use of electronic fetal monitoring (EFM) to include prevention of CP has resulted in decades of vastly increased interventions that have not significantly reduced the incidence of CP for infants born at term in the USA. Litigation alleging that poor obstetrical practice caused CP in most of these affected children has led to contentious arguments regarding the actual etiologies of this condition and often resulted in substantial monetary awards for plaintiffs. Recent advances in genetic testing using whole exome sequencing have revealed that at least one-third of CP cases in term infants are genetic in origin and therefore not labor-related. Here, we will present and discuss previous attempts to sort out contributing etiologies and ontogenies of CP, and how these newer diagnostic techniques are rapidly improving our ability to better detect and understand such cases. In light of these developments, we present our vision for an overarching spectrum for proper categorization of CP cases into that the following groups: (1) those begun at conception from genetic causes (nonpreventable); (2) those stemming from adverse antenatal/pre-labor events (possibly preventable with heightened antepartum assessment); (3) Those arising from intrapartum events (potentially preventable by earlier interventions); (4) Those occurring shortly after birth (possibly preventable with closer neonatal monitoring); (5) Those that appear later in the postnatal period from non-labor-related causes such as untreated infections or postnatal intracranial hemorrhages.

Study on the clinical value of the wearable foetal electrocardiogram monitoring system

BACKGROUND

Electronic foetal monitoring (EFM), a method to monitor foetal intrauterine conditions and foetal reserve capacity, is the most extensively used intrauterine monitoring technology in obstetrics.

OBJECTIVE

This study aims to compare the Thoth wearable foetal electrocardiogram (foetal ECG [FECG]) monitoring system with a traditional Doppler foetal heart monitoring system before labour to investigate their respective values in clinical application.

METHODS

A total of 393 pregnant women admitted to our hospital between 2020 and 2022 participated in this study. They were recruited using the convenience sampling method. We employed a paired design to assess the confusion rate, trend overlap, and foetal heart rate/ECG monitoring consistency, whereas a completely randomised design was used to measure pregnancy outcome indicators. The participants were divided into two groups using a random number table: the Thoth group (n= 196) and the traditional Doppler group (n= 197). Each group was monitored using the corresponding system.

RESULTS

The Thoth monitor demonstrated a lower confusion rate compared with the traditional Doppler monitor (0.25% vs 2.04%; χ2= 5.508, P= 0.019). The trend overlap in foetal heart rates was consistently 100%, with 91.2% of readings showing a consistency rate of ⩾ 95%. Additionally, the Thoth monitor recorded a higher cumulative interruption time in the foetal heart rate curve (12.13 ± 2.22 vs 21.02 ± 2.34; t= 18.471, P< 0.001) and more abnormal ECGs (21.21 ± 4.32 vs 18.21 ± 2.91; t= 7.582, P< 0.001) than the traditional Doppler system.

CONCLUSION

The Thoth wearable FECG monitor offers several advantages over the traditional Doppler foetal heart monitoring system. These include a reduced confusion rate, more accurate data collection, a lower rate of clinical misjudgement, reduced workload for medical staff, and enhanced comfort during vaginal delivery. The rates of emergency caesarean sections and neonatal asphyxia in the Thoth group were marginally lower than those in the Doppler group, which may be attributed to issues such as ECG disconnection or interference from the maternal heart rate.

The Impact of Total Deceleration Area and Fetal Growth on Neonatal Acidemia in Vacuum Extraction Deliveries

We aimed to investigate the correlation between total deceleration area (TDA), neonatal birthweight and neonatal acidemia in vacuum extractions (VEs). This is a retrospective study in a tertiary hospital, including VE performed due to non-reassuring fetal heart rate (NRFHR). Electronic fetal monitoring during the 120 min preceding delivery was interpreted by two obstetricians who were blinded to neonatal outcomes. TDA was calculated as the sum of the area under the curve for each deceleration. Neonatal birthweights were classified as low (<2500 g), normal (2500-3999 g) or macrosomic (>4000 g). A total of 85 VEs were analyzed. Multivariable linear regression, adjusted for gestational age, nulliparity and diabetes mellitus, revealed a negative correlation between TDA in the 60 min preceding delivery and umbilical cord pH. For every 10 K increase in TDA, the cord pH decreased by 0.02 (p = 0.038; 95%CI, -0.05-0.00). The use of the Ventouse-Mityvac cup was associated with a 0.08 decrease in cord pH as compared to the Kiwi OmniCup (95%CI, -0.16-0.00; p = 0.049). Low birthweights, compared to normal birthweights, were not associated with a change in cord pH. To conclude, a significant correlation was found between TDA during the 60 min preceding delivery and cord pH in VE performed due to NRFHR.

Abnormal fetal heart rate patterns caused by pathophysiologic processes other than fetal acidemia

Fetal acidemia is a common final pathway to fetal death, and in many cases, to fetal central nervous system injury. However, certain fetal pathophysiological processes are associated with significant category II or category III fetal heart rate changes before the development of or in the absence of fetal acidemia. The most frequent of these processes include fetal infection and/or inflammation, anemia, fetal congenital heart disease, and fetal central nervous system injury. In the presence of significant category II or category III fetal heart rate patterns, clinicians should consider the possibility of the aforementioned fetal processes depending on the clinical circumstances. The common characteristic of these pathophysiological processes is that their associated fetal heart rate patterns are linked to increased adverse neonatal outcomes despite the absence of acidemia at birth. Therefore, in these cases, the fetal heart rate patterns may provide more insight about the fetal condition and pathophysiology than the acid-base status at birth. In addition, as successful timing of intrapartum interventions on the basis of evolution of fetal heart rate patterns aims to prevent fetal acidemia, it may not be logical to continue to use the fetal acid-base status at birth as the gold standard outcome to determine the predictive ability of category II or III fetal heart rate patterns. A more reasonable approach may be to use the umbilical cord blood acid-base status at birth as the gold standard for determining the appropriateness of the timing of our interventions.

Resistance to Change

Advances in medical technology do not follow a smooth process and are highly variable. Implementation can occasionally be rapid, but often faces varying degrees of resistance resulting at the very least in delayed implementation. Using qualitative comparative analysis, we have evaluated numerous technological advances from the perspective of how they were introduced, implemented, and opposed. Resistance varies from benign - often happening because of inertia or lack of resources to more active forms, including outright opposition using both appropriate and inappropriate methods to resist/delay changes in care. Today, even public health has become politicized, having nothing to do with the underlying science, but having catastrophic results. Two other corroding influences are marketing pressure from the private sector and vested interests in favor of one outcome or another. This also applies to governmental agencies. There are a number of ways in which papers have been buried including putting the thumb on the scale where reviewers can sabotage new ideas. Unless we learn to harness new technologies earlier in their life course and understand how to maneuver around the pillars of obstruction to their implementation, we will not be able to provide medical care at the forefront of technological capabilities.

Improving the interpretation of electronic fetal monitoring: the fetal reserve index

Electronic fetal monitoring, particularly in the form of cardiotocography, forms the centerpiece of labor management. Initially successfully designed for stillbirth prevention, there was hope to also include prediction and prevention of fetal acidosis and its sequelae. With the routine use of electronic fetal monitoring, the cesarean delivery rate increased from <5% in the 1970s to >30% at present. Most at-risk cases produced healthy babies, resulting in part from considerable confusion as to the differences between diagnostic and screening tests. Electronic fetal monitoring is clearly a screening test. Multiple attempts have aimed at enhancing its ability to accurately distinguish babies at risk of in utero injury from those who are not and to do this in a timely manner so that appropriate intervention can be performed. Even key electronic fetal monitoring opinion leaders admit that this goal has yet to be achieved. Our group has developed a modified approach called the "Fetal Reserve Index" that contextualizes the findings of electronic fetal monitoring by formally including the presence of maternal, fetal, and obstetrical risk factors and increased uterine contraction frequencies and breaking up the tracing into 4 quantifiable components (heart rate, variability, decelerations, and accelerations). The result is a quantitative 8-point metric, with each variable being weighted equally in version 1.0. In multiple previously published refereed papers, we have shown that in head-to-head studies comparing the fetal reserve index with the American College of Obstetricians and Gynecologists' fetal heart rate categories, the fetal reserve index more accurately identifies babies born with cerebral palsy and could also reduce the rates of emergency cesarean delivery and vaginal operative deliveries. We found that the fetal reserve index scores and fetal pH and base excess actually begin to fall earlier in the first stage of labor than was commonly appreciated, and the fetal reserve index provides a good surrogate for pH and base excess values. Finally, the last fetal reserve index score before delivery combined with early analysis of neonatal heart rate and acid/base balance shows that the period of risk for neonatal neurologic impairment can continue for the first 30 minutes of life and requires much closer neonatal observation than is currently being done.

Comparison of the predictive ability for perinatal acidemia in neonates between the NICHD 3-tier FHR system combined with clinical risk factors and the fetal reserve index

BACKGROUND

Electronic fetal monitoring alone is a poor screening test for detecting fetuses at risk of acidemia or asphyxia. We aimed to evaluation of predictive ability of the National Institute of Child Health and Human Development (NICHD) 3-tier fetal heart rate (FHR) system combined with the maternal, obstetric, and fetal risk factors for predicting perinatal acidemia, and to compare this with the predictive of the NICHD 3-tier system alone, and the Fetal Reserve Index (FRI).

METHODS

A retrospective cohort study was conducted among singleton term pregnant women. Fetal heart rate tracings of the last two hours before delivery were interpreted into the NICHD 3-tier FHR classification system by two experienced obstetricians. Demographic data were compared using the χ2 or Fisher's exact test for categorical variables and the Student's t test for continuous variables. Logistic regression model was used to identify factors associated with perinatal acidemia in neonates. The Odds ratios (OR) and probabilities with 95% confidence intervals (CI) were calculated.

RESULTS

A total of 674 pregnant women were enrolled in this study. Using the NICHD 3-tier FHR categories I and II combined with the selected risk factors (AUC 0.62) had a better performance for perinatal acidemia prediction than the NICHD 3-tier FHR alone (AUC 0.55) and the FRI (AUC 0.52), (P<0.01). Improvement of predicting perinatal acidemia was found when NICHD category I was combined with preeclampsia or arrest disorders of labor (OR 3.2, 95% CI 1.30‒7.82) or combined with abnormal second stage of labor (OR 6.19, 95% CI 1.07‒36.06) and when NICHD category II was combined with meconium-stained amniotic fluid (OR 4.73, 95% CI 2.17‒10.31).

CONCLUSIONS

The NICHD 3-tier FHR categories I or II combined with selected risk factors can improve the predictive ability of perinatal acidemia in neonates compared with the NICHD 3-tier system alone or the FRI.

Approaches to Preventing Intrapartum Fetal Injury

Electronic fetal monitoring (EFM) was introduced into obstetric practice in 1970 as a test to identify early deterioration of fetal acid-base balance in the expectation that prompt intervention ("rescue") would reduce neonatal morbidity and mortality. Clinical trials using a variety of visual or computer-based classifications and algorithms for intervention have failed repeatedly to demonstrate improved immediate or long-term outcomes with this technique, which has, however, contributed to an increased rate of operative deliveries (deemed "unnecessary"). In this review, we discuss the limitations of current classifications of FHR patterns and management guidelines based on them. We argue that these clinical and computer-based formulations pay too much attention to the detection of systemic fetal acidosis/hypoxia and too little attention not only to the pathophysiology of FHR patterns but to the provenance of fetal neurological injury and to the relationship of intrapartum injury to the condition of the newborn. Although they do not reliably predict fetal acidosis, FHR patterns, properly interpreted in the context of the clinical circumstances, do reliably identify fetal neurological integrity (behavior) and are a biomarker of fetal neurological injury (separate from asphyxia). They provide insight into the mechanisms and trajectory (evolution) of any hypoxic or ischemic threat to the fetus and have particular promise in signaling preventive measures (1) to enhance the outcome, (2) to reduce the frequency of "abnormal" FHR patterns that require urgent intervention, and (3) to inform the decision to provide neuroprotection to the newborn.

Associations between fetal heart rate variability and umbilical cord occlusions-induced neural injury: An experimental study in a fetal sheep model

INTRODUCTION

This study evaluated the association between fetal heart rate variability (HRV) and the occurrence of hypoxic-ischemic encephalopathy in a fetal sheep model.

MATERIAL AND METHODS

The experimental protocol created a hypoxic condition with repeated cord occlusions in three phases (A, B, C) to achieve acidosis to pH <7.00. Hemodynamic, gasometric and HRV parameters were analyzed during the protocol, and the fetal brain, brainstem and spinal cord were assessed histopathologically 48 h later. Associations between the various parameters and neural injury were compared between phases A, B and C using Spearman's rho test.

RESULTS

Acute anoxic-ischemic brain lesions in all regions was present in 7/9 fetuses, and specific neural injury was observed in 3/9 fetuses. The number of brainstem lesions correlated significantly and inversely with the HRV fetal stress index (r = -0.784; p = 0.021) in phase C and with HRV long-term variability (r = -0.677; p = 0.045) and short-term variability (r = -0.837; p = 0.005) in phase B. The number of neurological lesions did not correlate significantly with other markers of HRV.

CONCLUSIONS

Neural injury caused by severe hypoxia was associated with HRV changes; in particular, brainstem damage was associated with changes in fetal-specific HRV markers.

Changing Perspectives of Electronic Fetal Monitoring

The delivery of healthy babies is the primary goal of obstetric care. Many technologies have been developed to reduce both maternal and fetal risks for poor outcomes. For 50 years, electronic fetal monitoring (EFM) has been used extensively in labor attempting to prevent a large proportion of neonatal encephalopathy and cerebral palsy. However, even key opinion leaders admit that EFM has mostly failed to achieve this goal. We believe this situation emanates from a fundamental misunderstanding of differences between screening and diagnostic tests, considerable subjectivity and inter-observer variability in EFM interpretation, failure to address the pathophysiology of fetal compromise, and a tunnel vision focus. To address these suboptimal results, several iterations of increasingly sophisticated analyses have intended to improve the situation. We believe that part of the continuing problem is that the focus of EFM has been too narrow ignoring important contextual issues such as maternal, fetal, and obstetrical risk factors, and increased uterine contraction frequency. All of these can significantly impact the application of EFM to intrapartum care. We have recently developed a new clinical approach, the Fetal Reserve Index (FRI), contextualizing EFM interpretation. Our data suggest the FRI is capable of providing higher accuracy and earlier detection of emerging fetal compromise. Over time, artificial intelligence/machine learning approaches will likely improve measurements and interpretation of FHR characteristics and other relevant variables. Such future developments will allow us to develop more comprehensive models that increase the interpretability and utility of interfaces for clinical decision making during the intrapartum period.

Correlation between total deceleration area and fetal cord blood pH in neonates complicated with meconium-stained amniotic fluid at term

OBJECTIVE

To assess the correlation between total area under the Curve (AUC) of decelerations and accelerations and neonatal acidemia in pregnancies complicated with meconium-stained amniotic fluid (MSAF).

METHODS

A retrospective cohort study was conducted among women who delivered with a diagnosis of MSAF. Electronic fetal monitoring (EFM) patterns 120 min before delivery were interpreted by a researcher blinded to fetal outcomes. The primary outcome was fetal acidemia, defined as umbilical artery pH below 7.10. The correlation was tested using the Spearman correlation coefficient.

RESULTS

A total of 102 women were included; 24 delivered infants with cord blood pH < 7.20, and only five delivered infants with cord blood pH < 7.10. A significant correlation was demonstrated between total AUC of decelerations and accelerations and cord blood pH (P = 0.02). A sub-analysis according to gestational age at delivery (up to and beyond 40 weeks) was conducted. A significant correlation was demonstrated (P = 0.02) only in the term group(n = 37).

CONCLUSION

A correlation was demonstrated between total AUC of decelerations and accelerations and cord blood pH in neonates with MSAF. This correlation was significant for neonates delivered before 40 weeks of gestation, but not for those delivered after 40 weeks of gestation.

Relationship Between Deceleration Morphology and Phase Rectified Signal Averaging-Based Parameters During Labor

During labor, uterine contractions trigger the response of the autonomic nervous system (ANS) of the fetus, producing sawtooth-like decelerations in the fetal heart rate (FHR) series. Under chronic hypoxia, ANS is known to regulate FHR differently with respect to healthy fetuses. In this study, we hypothesized that such different ANS regulation might also lead to a change in the FHR deceleration morphology. The hypothesis was tested in an animal model comprising nine normoxic and five chronically hypoxic fetuses that underwent a protocol of umbilical cord occlusions (UCOs). Deceleration morphologies in the fetal inter-beat time interval (FRR) series were modeled using a trapezoid with four parameters, i.e., baseline b, deceleration depth a, UCO response time τ u and recovery time τ r . Comparing normoxic and hypoxic sheep, we found a clear difference for τ u (24.8±9.4 vs. 39.8±9.7 s; p < 0.05), a (268.1±109.5 vs. 373.0±46.0 ms; p < 0.1) and Δτ = τ u - τ r (13.2±6.9 vs. 23.9±7.5 s; p < 0.05). Therefore, the animal model supported the hypothesis that hypoxic fetuses have a longer response time τ u and larger asymmetry Δτ as a response to UCOs. Assessing these morphological parameters during labor is challenging due to non-stationarity, phase desynchronization and noise. For this reason, in the second part of the study, we quantified whether acceleration capacity (AC), deceleration capacity (DC), and deceleration reserve (DR), computed through Phase-Rectified Signal Averaging (PRSA, known to be robust to noise), were correlated with the morphological parameters. DC, AC and DR were correlated with τ u , τ r and Δτ for a wide range of the PRSA parameter T (Pearson's correlation ρ > 0.8, p < 0.05). In conclusion, deceleration morphologies have been found to differ between normoxic and hypoxic sheep fetuses during UCOs. The same difference can be assessed through PRSA based parameters, further motivating future investigations on the translational potential of this methodology on human data.

Uterine contraction frequency in the last hour of labor: how many contractions are too many?

OBJECTIVE

Increased frequency of uterine contractions is a component in the cluster of causal conditions that can lead to fetal hypoxia and acidosis and increase the risk for neonatal neurologic injury. For most international obstetrical societies, 5 contractions per 10 min averaged over 30 min is considered as the upper limit of normal uterine activity. We hypothesize that it might be safer to adopt an upper limit of 4 contractions per 10 min.

METHODS

We reviewed our 1970's research database containing 475 patients with closely monitored and well-documented labor and neonatal assessments that included cord blood (CB) pH, base excess (BE), and continuous recording of neonatal heart rate (NHR). Using data segregated by the proportion of the last hour before delivery when uterine contraction frequency (UCF) exceeded 4 and 5 contractions per 10 min respectively, we evaluated outcomes (CB BE, pH, Apgar scores at 1 min, the status of NHR at 16 min after birth, and the proportion of births that did not the result from normal spontaneous vaginal deliveries (NSVDs). ANOVA established relationships between UCF cutoffs and these outcomes. Our sample size is sufficiently large to provide the ability of UCF, per se, to accurately detect an alpha region of .05 88% of the time with an effect size of .15.

RESULTS

During the last hour prior to delivery, a UCF cutoff at 4 contractions per 10 min performed better than a UCF cutoff at 5 contractions per 10 min to enable the earlier identification of risks for abnormal outcomes. The longer UCF was increased, the worse were the outcomes that were measured, and the region >4 but ≤5 contractions identifies the beginnings of worsening conditions in a variety of measures of poor outcomes.

CONCLUSION

Lowering the recommended threshold for UCF from 5 to 4 contractions per 10-minute period as averaged over 30 min facilitates earlier detection of potentially compromised fetuses and is also an important contributor to a multicomponent contextualized approach to risk assessment.

Timing intrapartum management based on the evolution and duration of fetal heart rate patterns

One of the most important challenges in obstetrics is to determine the appropriate time to deliver the fetus without exposing the mother to unnecessary operative interventions. The use of continuous cardiotocography (cCTG) during labor has resulted in dramatic reductions in intrapartum fetal deaths, but fetal central nervous system (CNS) injury and cerebral palsy (CP) rates have remain relatively unchanged as related to the use of cCTG . In our view, this is due to continuing inability to recognize progressive fetal deterioration and intervene promptly prior to the development of fetal CNS injury. Although the 2008 NICHD workshop proposed a 3-tier classification system, most fetuses born with severe (pathologic) acidemia (cord artery pH < 7.00), as well as those who eventually develop CP, will never reach the stage of NICHD Category III fetal heart rate (FHR) pattern. In the present "Clinical Opinion," we promote a concept derived from observations, that the evolution of the FHR changes of the deteriorating fetus can be visually defined by three color "zones" that are clinically recognizable and, therefore, are actionable. In addition, we will review information regarding how long the fetus may be able to tolerate an abnormal FHR pattern before it suffers an adverse perinatal outcome, an area of investigation that has been rarely addressed before. Based on the available evidence, Category III FHR patterns should not be used as screening criteria because of low sensitivity for either fetal CNS injury (45%) or severe (pathologic) fetal acidemia (36-44%). In addition, the duration of the Category III pattern required for the development of severe fetal acidemia is extremely short to allow for a timely preventative operative intervention. On the contrary, the use of our proposed "red" zone, which includes the most advanced stages in the progressive deterioration of Category II patterns and Category III, will identify the overwhelming majority of fetuses who develop severe (pathologic) acidemia (96%) and/or CNS injury during labor (100%); moreover, the detection of fetal jeopardy by the use of the "red" zone occurs much earlier, as compared to using Category III, thus allowing reasonable amount of time for a timely obstetrical intervention. Further research is needed to determine the false positive rate and positive predictive value for a pre-determined period of time in the red zone.

Total intrapartum fetal reperfusion time (fetal resilience) and neonatal acidemia

OBJECTIVE

The main objective is to study the predictive capacity of intrapartum total fetal reperfusion (fetal resilience) by itself or in combination with other parameters as a predictor of neonatal acidemia.

STUDY DESIGN

A retrospective case-control study was carried out at the Miguel Servet University Hospital (Zaragoza, Spain) on a cohort of 5694 pregnant women between June 2017 and October 2018. Maternal, perinatal, and cardiotocographic records were collected. Two reviewers blindly described the monitors with the American College of Obstetricians and Gynecologists (ACOG) categorizations and parameters and the non-ACOG parameters. Neonatal acidemia was defined as pH <7.10. The parameters analyzed to predict acidemia were evaluated using the sensitivity for specificity 90% value, and the area under the receiver operating characteristic curve.

RESULTS

We recorded 192 infants with acidemia, corresponding to a global acidemia rate of 3.4%. Of these, 72 were excluded for lack of criteria, leaving 120 patients with arterial acidemia included in the study and 258 in the control group. The sensitivity (specificity 90%) of detection of acidemia was 42% for the ACOG III categorization (AUC, 0.524: 95% CI, 0.470-0.578), 24% for fetal reperfusion (AUC, 0.704: 95% CI, 0.649-0.759), 27% for total area of decelerations (AUC, 0.717: 95% CI, 0.664-0.771) and 50% for the multivariate model built from total reperfusion time (AUC, 0.826: 95% CI, 0.783-0.869). The total reperfusion time corresponding to a false negative rate of 10% is 23.75 min, with 28% of fetuses above this time. The AUC and sensitivity for a false negative rate of 10% are equivalent for deceleration area and time of reperfusion (p = .504).

CONCLUSION

The total reperfusion time (fetal resilience) and total deceleration area are non-ACOG parameters with a good predictive ability for neonatal acidemia, higher than the ACOG III classification and without statistical differences between them. The discrimination ability of total reperfusion time can be improved using a multivariate model. As a cutoff for its use we suggest 23.75 min in 30 min corresponding to an acidemic classification rate of 90%. New parameters in combination with other maternal, obstetrics, or fetal variables, are required for the interpretation of fetal well-being.

Prediction of severe adverse neonatal outcomes at the second stage of labour using machine learning: a retrospective cohort study

OBJECTIVE

To create a personalised machine learning model for prediction of severe adverse neonatal outcomes (SANO) during the second stage of labour.

DESIGN

Retrospective Electronic-Medical-Record (EMR) -based study.

POPULATION

A cohort of 73 868 singleton, term deliveries that reached the second stage of labour, including 1346 (1.8%) deliveries with SANO.

METHODS

A gradient boosting model was created, analysing 21 million data points from antepartum features (e.g. gravidity and parity) gathered at admission to the delivery unit, and intrapartum data (e.g. cervical dilatation and effacement) gathered during the first stage of labour. Deliveries were allocated to high-risk and low-risk groups based on the Youden index to maximise sensitivity and specificity.

MAIN OUTCOME MEASURES

SANO was defined as either umbilical cord pH levels ≤7.1 or 1-minute or 5-minute Apgar score ≤7.

RESULTS

The model for prediction of SANO yielded an area under the receiver operating curve (AUC) of 0.761 (95% CI 0.748-0.774). A third of the cohort (33.5%, n = 24 721) were allocated to a high-risk group for SANO, which captured up to 72.1% of these cases (odds ratio 5.3, 95% CI 4.7-6.0; high-risk versus low-risk groups).

CONCLUSIONS

Data acquired throughout the first stage of labour can be used to predict SANO during the second stage of labour using a machine learning model. Stratifying parturients at the beginning of the second stage of labour in a 'time out' session, can direct a personalised approach to management of this challenging aspect of labour, as well as improve allocation of staff and resources.

TWEETABLE ABSTRACT

Personalised prediction score for severe adverse neonatal outcomes in labour using machine learning model.

Mid forceps did not cause "compromised babies" - "compromise" caused forceps: an approach toward safely lowering the cesarean delivery rate

OBJECTIVE

Over 5 decades, Cesarean Delivery rates (CDR) have risen 6-fold while vaginal operative deliveries [VODs] decreased from >20% to ∼3%. Poor outcomes (HIE and cerebral palsy) haven't improved. Potentiating the virtual abandonment of forceps (F), particularly midforceps (Mid), were allegations about various poor neonatal outcomes. Here, we evaluate VOD and CDR outcomes controlling for prior fetal risk metrics (PR) ascertained an hour before birth.

METHODS

Our 45-year-old database from a labor research unit of moderate/high risk laboring patients (288 NSVDs, 120 Lows, 30 Mids, and 32 CDs) had multiple fetal scalp samples for base excess (BE), pH, cord blood gases (CB), and umbilical artery bloods. ANOVA established relationships between birth methods and outcomes (Cord blood BE and pH and 1 and 5 min Apgar scores); correlations, and two-step multiple regression assessed PR for delivery method and neonatal outcomes. The main outcome measures were correlations of outcome measures with fetal scalp sample BE and pH up to an hour before delivery and fetal reserve index scores scored concurrently.

RESULTS

NSVDs had the best immediate neonatal outcomes with significantly higher CB pH and BE as compared to forceps and CDs. However, controlling for PR revealed: (1) PR at 1 h before delivery correlated with delivery mode, i.e. the decrements in outcomes were already present before the delivery was performed; and (2) The presumed deleterious effects of interventional deliveries, per se, were significantly reduced, and (3) Fetal Reserve Index predicted neonatal outcomes better than fetal scalp sample BE, pH, or delivery mode.

CONCLUSION

The historical belief that MF deliveries caused poorer outcomes than NSVDs seems mostly backwards. Appreciating PR's impact on delivery routes, and when appropriate, properly performing VODs could safely reduce CDR. If our approach lowered CDR by only ∼2%, in the United States about 80,000 CDs might be avoided, saving ∼$750 Million yearly. In the post pandemic world, safely apportioning medical expenses will be even more critical than previously.

Earlier and improved screening for impending fetal compromise

OBJECTIVE

The use of pH and base excess (FSSPHBE) from fetal scalp sampling (FSS) was abandoned when cardiotocography (CTG) was believed to be sufficiently accurate to direct patient management. We sought to understand the fetus' tolerance to stress in the 1st stage of labor and to develop a better and earlier screening test for its risk for developing acidosis. To do so, we investigated sequential changes in fetal pH and BE obtained from FSS in the 1st stage of labor as part of a research protocol from the 1970s. We then examined the utility of multiple of the median (MoM's) conversion of BE and pH values, and the capacity of Fetal Reserve Index (FRI) scores to be a proxy for such changes. We then sought to examine the predictive capacity of 1st stage FRI and its change over the course of the first stage of labor for the subsequent development of acidosis risk in the 2nd stage of labor.

METHODS

Using a retrospective research database evaluation, we evaluated FSSPHBE data from 475 high-risk parturients monitored in labor and their neonates for 1 h postpartum. We categorized specimens according to cervical dilatation (CxD) at the time of FSSPHBE and developed non-parametric, multiples of the median (MOMs) assessments. FRI scores and their change over time were used as predictors of FSSPHBE. Our main outcome measures were the changes in BE and pH at different cervical dilatations (CxD) and acidosis risk in the early 2nd stage of labor.

RESULTS

FSSPHBE worsens over the course of the 1st stage. The implications of any given BE are very different depending upon CxD. At 9 cm, -8 Mmol/L is 1.1 MOM; at 3 cm, it would be 2.0 MOM. The FRI level and its trajectory provide a 1st stage screening tool for acidosis risk in the second stage.

CONCLUSIONS

Fetal acid-base balance ("reserve") deteriorates beginning early in the 1st stage of labor, irrespective of whether the fetus reaches a critical threshold of concern for actual acidosis. The use of MoM's logic improves appreciation of such information. The FRI and its trajectory reasonably approximate the trajectory of the FSSPHBE and appears to be a suitable screening test for early deterioration and for earlier interventions to keep the fetus out of trouble rather than wait until high risk status develops.

Combined prenatal and postnatal prediction of early neonatal compromise risk

OBJECTIVE

Electronic fetal monitoring/cardiotocography (EFM) is nearly ubiquitous, but almost everyone acknowledges there is room for improvement. We have contextualized monitoring by breaking it down into quantifiable components and adding to that, other factors that have not been formally used: i.e. the assessment of uterine contractions, and the presence of maternal, fetal, and obstetrical risk factors. We have created an algorithm, the Fetal Reserve Index (FRI) that significantly improves the detection of at-risk cases. We hypothesized that extending our approach of monitoring to include the immediate newborn period could help us better understand the physiology and pathophysiology of the decrease in fetal reserve during labor and the transition from fetal to neonatal homeostasis, thereby further honing the prediction of outcomes. Such improved and earlier understanding could then potentiate earlier, and more targeted use of neuroprotective attempts during labor treating decreased fetal reserve and improving the fetus' transition from fetal to neonatal life minimizing risk of neurologic injury.

STUDY DESIGN

We have analyzed a 45-year-old research database of closely monitored labors, deliveries, and an additional hour of continuous neonatal surveillance. We applied the FRI prenatally and created a new metric, the INCHON index that combines the last FRI with umbilical cord blood and 4-minute umbilical artery blood parameters to predict later neonatal acid/base balance. Using the last FRI scores, we created 3 neonatal groups. Umbilical cord and catheterized umbilical artery bloods at 4, 8, 16, 32, and 64 minutes were measured for base excess, pH, and PO₂. Continuous neonatal heart rate was scored for rate, variability, and reactivity.

RESULTS

Neonates commonly do not make a smooth transition from fetal to postnatal physiology. Even in low risk babies, 85% exhibited worsening pH and base excess during the first 4 minutes; 34% of neonates reached levels considered at high risk for metabolic acidosis (≤-12 mmol/L) and neurologic injury. Neonatal heart rate commonly exhibited sustained, significant tachycardia with loss of reactivity and variability. One quarter of all cases would be considered Category III if part of the fetal tracing. Our developed metrics (FRI and INCHON) clearly discriminated and predicted low, medium, and high-risk neonatal physiology.

CONCLUSIONS

The immediate neonatal period often imposes generally unrecognized risks for the newborn. INCHON improves identification of decreased fetal reserve and babies at risk, thereby permitting earlier intervention during labor (intrauterine resuscitation) or potentially postnatally (brain cooling) to prevent neurologic injury. We believe that perinatal management would be improved by routine, continuous neonatal monitoring - at least until heart rate reactivity is restored. FRI and INCHON can help identify problems much earlier and more accurately than currently and keep fetuses and babies in better metabolic shape.

Risk management and provider liabilities in infantile cerebral palsy based on malpractice litigation cases

AIM

Infantile cerebral palsy (CP) severely affects the survival and quality of life of infants. CP is typically caused by multiple factors, leading to causal uncertainty of the role of medical errors in CP and resulting in frequent medical disputes. No relevant research exists on risk management and malpractice liabilities in CP, including in China.

METHOD

A retrospective analysis of 400 CP malpractice litigation cases from 18th June 1999 to 23rd November 2017, collected from China Judgments Online, included basic case information, CP risk factors, medical errors, medical malpractice liability determination, and compensation.

RESULTS

Up to 63.5% of infants with CP were affected by asphyxia, followed by hypoxic-ischemic encephalopathy (63.3%), neonatal infection (52.3%) and intracranial hemorrhage (36.0%). Most (89.1%) of civil judgments resulted in liability for medical errors, with the highest proportion of ultimate liability. The three most frequent medical errors were failure of completing delivery in time (30.2%), incomplete assessment of birth process detection (28.8%), and nonstandard medical records (25.3%). Each case involved 2.5 medical errors on average. No difference in the distribution of medical errors between premature and full-term CP infants (P > 0.05) was found. Compensation for damage was awarded in 91.4% of claims, and the mean value of compensation was $73,506. The mean value of the total actual loss of the family was $128,198.

INTERPRETATION

Contradictions between the doctors and patients were prominent in malpractice CP litigation cases, with a total loss of $3.97 billion attributable to new CP cases in China in 2017. Asphyxia was the most frequent risk factor for CP since it may easily draw the attention of the sufferer's family. Medical service providers did not pay attention to risk management in preterm infants. The importance of fetal monitoring and standardized medical record writing should be emphasized.

Refining the Prediction and Prevention of Emergency Operative Deliveries with the Fetal Reserve Index

Electronic fetal monitoring (EFM) is a poor predictor of outcomes attributable to delivery problems. Contextualizing EFM by adding maternal, obstetrical, and fetal risk-related information to create an index called the Fetal Reserve Index (FRI) improves the predictive capacity and facilitates the timing of interventions. Here, we test critical assumptions of FRI as a clinical tool. Our conceptualization implies that the earlier one reaches the red zone (FRI ≤25) and the longer one spends in the red zone, the greater the likelihood of emergency operative deliveries (EOD).

METHODS

We analyzed 1,402 patients using logistic regression predicting the probability of EOD and employed qualitative methodology techniques to refine predictive capabilities.

RESULTS

Reaching the red zone early and staying there > 1 h increases the probability of EOD. When these risk factors are paired with intrauterine resuscitation (IR) in Stage 1, the reduction of EOD is substantial.

CONCLUSION

FRI is a capable predictor of EOD because it accurately identifies the level of malleable risk. FRI analysis increases the risk of using IR in Stage 1. Matching risk and resources dramatically reduces the chances of EOD. Earlier IR improves the outcomes if the calculated risk is high.

Safely lowering the emergency Cesarean and operative vaginal delivery rates using the Fetal Reserve Index

Objective: The cardiotocograph (CTG) or electronic fetal monitoring (EFM) was developed to prevent fetal asphyxia and subsequent neurological injury. From a public health perspective, it has failed these objectives while increasing emergency operative deliveries (emergency operative deliveries (EODs) - emergency cesarean delivery or operative vaginal delivery) for newborns, who in retrospect, actually did not require the assistance. EODs increase the risks of complications and stress for patients, families, and medical personnel. A safe reduction in the need for EOD will likely reduce both the overall Cesarean section rate as well as the risk of fetal neurological injury during labor to which it is related. We have developed the fetal reserve index (FRI), which is more comprehensive than CTG as a new screening method for early identification of the fetus at-risk of both neurological harm and the need to "rescue" by means of an EOD. Here, we compare prospectively the need for EOD in two groups of parturients undergoing a trial of labor at term. One group was managed conventionally, the other by the principles of the FRI.Study design: We compared the need for EOD of 800 parturients with singleton cases undergoing a trial of labor at term entering with normal CTG patterns (ACOG category 1). Patients were either treated routinely (400 - "early cases") or in a second group seen later actively managed using the principles of the FRI (400 - "late cases"). The FRI includes measurements of five components of the CTG: rate, variability, decelerations, accelerations, and abnormal uterine activity combined with the presence of medical, obstetrical, and fetal risk factors. The 8-point metric categorizes cases as "green", "yellow", and "red" with the latter being at risk.Results: All 800 patients delivered babies, who were discharged in the usual time course with no untoward outcomes noted. The incidence of red zone scores was comparable in the two groups (≈25%), but the use of intrauterine resuscitation (IR) when reaching the red zone in the late group (47%) was more than double the incidence in the early group (20%) (p < .001). Despite (or because of) this, EODs were significantly reduced in the late group, from 17.3 to 4.0% (p < .001). Further, the late group spent less time in the red zone without increasing overall time in labor. Overall, EOD cases averaged >1 h in the red zone versus 0.5 h for non-EODs.Conclusions: The FRI may provide a metric to reduce EODs and by extension also reduce the risks of both cesarean delivery and adverse fetal/neonatal outcomes. The safe avoidance of EOD would seem to be an important metric to assess the quality of intrapartum management. This study represents the first attempt to apply the principles of the FRI "live" for the concurrent management of patients during labor. These promising results, if confirmed, in larger sample sizes, set the stage for our computerization of the FRI for widespread study. Benefits appear to come from identification and early, conservative management of fetal deterioration before the need to "rescue" the fetus by EOD.