An evaluation of fetal heart rate characteristics associated with neonatal encephalopathy: a case-control study

Labor management and neonatal outcomes in cardiotocography categories II and III (Review)

The safe care of both mothers and fetuses during labor is a primary goal of all health professionals. The assessment of fetal oxygenation and well-being is a key aspect of perinatal care provided. Fetal heart rate (FHR) auscultation became part of daily obstetric practice in a number of countries during the 20th century and remains a key method of fetal monitoring, particularly in low-risk pregnancies. Cardiotocography (CTG) is the continuous monitoring and recording of the FHR and uterine myometrial activity, making it possible to assess the fetal condition. It therefore plays a critical role in the detection of fetal hypoxia during labor, a condition directly related to short- and long-term complications in the newborn. Herein, particular reference is made to the management of CTG category II and III standards, as well as to the handling of childbirth. In addition, specific FHR patterns are associated with immediate neonatal outcomes based on updated studies conducted worldwide. Finally, the prognostic significance of CTG and its potential as a prospective avenue for further investigation are also highlighted herein. Given that the misinterpretation of CTG findings is the most common cause of medical-legal responsibility, this knowledge field requires more emphasis and attention. The aim of the present review was to further deepen the knowledge on issues that mainly concern the safety and monitoring of pregnant women and fetuses during childbirth.

Cardiotocography use for fetal assessment during labor in low- and middle-income countries: A scoping review

BACKGROUND

The use of cardiotocography (CTG) to improve neonatal outcomes is controversial. The medical settings, subjects, utilizations, and interpretation guidelines of CTG are unclear for low- and middle-income countries (LMICs).

OBJECTIVES

To assess and review CTG use for studies identified in LMICs and provide insights on the potential for effective use of CTG to improve maternal and neonatal outcomes.

SEARCH STRATEGY

The databases Medline, CINAHL, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for published and unpublished literature through September 2023.

SELECTION CRITERIA

Publications were identified which were conducted in LMICs, based on the World Bank list of economies for 2019; targeting pregnant women in childbirth; and focusing on the utilization of CTG and neonatal outcomes.

DATA COLLECTION AND ANALYSIS

Publications were screened, and duplicates were removed. A scoping review was conducted using PRISMA-ScR guidelines.

RESULTS

The searches generated 1157 hits, of which 67 studies were included in the review. In the studies there was considerable variation and ambiguity regarding the study settings, target populations, utilizations, timing, frequency, and duration of CTG. While cesarean section rates were extensively investigated as an outcome of studies of CTG itself and the effect of additional techniques on CTG, other clinically significant outcomes, including neonatal mortality, were not well reported.

CONCLUSIONS

Variations and ambiguities were found in the use of CTG in LMICs. Due to the limited amount of evidence, studies are needed to examine CTG availability in the context of LMICs.

Fetal monitoring technologies for the detection of intrapartum hypoxia - challenges and opportunities

Intrapartum fetal hypoxia is related to long-term morbidity and mortality of the fetus and the mother. Fetal surveillance is extremely important to minimize the adverse outcomes arising from fetal hypoxia during labour. Several methods have been used in current clinical practice to monitor fetal well-being. For instance, biophysical technologies including cardiotocography, ST-analysis adjunct to cardiotocography, and Doppler ultrasound are used for intrapartum fetal monitoring. However, these technologies result in a high false-positive rate and increased obstetric interventions during labour. Alternatively, biochemical-based technologies including fetal scalp blood sampling and fetal pulse oximetry are used to identify metabolic acidosis and oxygen deprivation resulting from fetal hypoxia. These technologies neither improve clinical outcomes nor reduce unnecessary interventions during labour. Also, there is a need to link the physiological changes during fetal hypoxia to fetal monitoring technologies. The objective of this article is to assess the clinical background of fetal hypoxia and to review existing monitoring technologies for the detection and monitoring of fetal hypoxia. A comprehensive review has been made to predict fetal hypoxia using computational and machine-learning algorithms. The detection of more specific biomarkers or new sensing technologies is also reviewed which may help in the enhancement of the reliability of continuous fetal monitoring and may result in the accurate detection of intrapartum fetal hypoxia.

Increased variability of fetal heart rate during labour: a review of preclinical and clinical studies

Increased fetal heart rate variability (FHRV) in intrapartum cardiotocographic recording has been variably defined and poorly understood, limiting its clinical utility. Both preclinical (animal) and clinical (human) evidence support that increased FHRV is observed in the early stage of intrapartum fetal hypoxaemia but can also be observed in a subset of fetuses during the preterminal stage of repeated hypoxaemia. This review of available evidence provides data and expert opinion on the pathophysiology of increased FHRV, its clinical significance and a stepwise approach regarding the management of this pattern, and propose recommendations for standardisation of related terminology.

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.

Appraisal of trimester-specific fetal heart rate and its role in gestational age prediction

INTRODUCTION

The aim of this study was to evaluate and report normal sonographic FHR values among low-risk singleton women across the three trimesters of pregnancy and determine FHR role in gestational age prediction.

METHOD

A prospective cross-sectional study of 2727 low-risk singleton pregnant women was undertaken. FHR measurements were obtained by a consultant radiologist and three experienced sonographers using transabdominal approach from January 2019 to December 2020. Two FHR measurements were taken for each participant. The fetal lie and presentation were also documented in the first trimester. Data were analysed using SPSS version 24 (IBM, Armonk, NY, USA).

RESULT

The maternal mean ± SD age was 25.8 ± 6.5 years and mean FHR for first, second and third trimesters were 151 ± 16, 145 ± 6 and 125±6 bpm respectively. The mean ± SD gestational age were 10 ± 2, 19 ± 3 and 34 ± 2 weeks for the first, second and third trimester respectively. Using ANOVA, there were statistically significant differences in FHR across the three trimesters (p ≤ 0.05). A positive correlation existed between maternal age and FHR (r = 0.57, p ≤ 0.05).

CONCLUSION

This study has established normal values for FHR in first, second and third trimester respectively. Referring physicians, radiologists, sonographers, obstetricians and gynaecologists may consider FHR of (135-167) bpm (139-151) bpm and (119-131) bpm as normal FHR ranges for the first, second and third trimester respectively. This study has also revealed the possibility of gestational age prediction using FHR with the equation [Gestational Age = 87.8 - (0.47) FHR].

IMPLICATIONS FOR PRACTICE

This paper provides the most up-to-date sonographic FHR recommendations for fetal management. More importantly, findings from this study also suggests that ultrasound practitioners can use FHR measurements as a reliable alternative for fetal dating.

Fetal heart rate patterns in labor and the risk of neonatal encephalopathy: A case control study

OBJECTIVE

To describe the accuracy of intrapartum fetal heart rate abnormalities as defined by National Institute of Health and Care Excellence guidelines to predict moderate-severe neonatal encephalopathy of apparent hypoxic-ischemic etiology.

STUDY DESIGN

A case-control study of HIE risk factors was conducted. Eligible babies were born in a single maternity hospital in Dublin, Ireland between September 2006, and November 2017 at ≥35 + 0 weeks' gestational age. Cases were eligible babies with moderate-severe neonatal encephalopathy of definite or apparent hypoxic-ischemic etiology. Controls were eligible babies born before and after each case with normal Apgar scores. The included subjects who had intrapartum fetal heart rate recordings were identified. Pattern features (baseline rate, variability, accelerations, decelerations [early, late, variable, prolonged], bradycardia, sinusoidal pattern) were manually identified blind to all clinical details by one of the authors. Each 15-minute segment was then algorithmically categorized (uninterpretable, normal, suspicious, pathological).

RESULTS

Of 88 cases and 176 controls, 71 cases (81%) and 146 controls (83%) were admitted to the delivery suite in labor. From that group, intrapartum FHR traces longer than 15 min were available for 52 (73%) cases and 118 (83%) controls. The FHR pattern feature with the largest area under the receiver operating characteristic curve was the maximum number of consecutive segments in which the baseline was >160 bpm (0.71 [95% confidence interval: 0.62-0.80]). The category variable with the highest area under the curve was the number of suspicious segments (0.76 [95% confidence interval: 0.67-0.84]). A tri-variate logistic regression model incorporating the total number of segments, the number of "suspicious" segments classed, and the number of "pathological" segments achieved an area under the curve of 0.78 (95% confidence interval: 0.70-0.86). With 95% specificity, this model correctly identified 17 cases (33%) at a median time before delivery of 2 h and 18 min (interquartile range: 01:19-04:40).

CONCLUSIONS

The power of fetal heart rate analysis to predict neonatal encephalopathy is hampered by poor specificity given the rarity of the outcome. When analyzing a suspicious trace, it is beneficial to consider the overall duration of the suspicious pattern.

MANUAL FETAL STIMULATION DURING INTRAPARTUM FETAL SURVEILLANCE: A RANDOMISED CONTROLLED TRIAL: CharacteristicMaternal outcome

BACKGROUND

Manual fetal stimulation, either by mechanical manipulation or by stimulation of the fetal scalp is known to evoke a fetal heart response in a normal fetus.

OBJECTIVES

To assess the clinical effectiveness of manual fetal stimulation in assessment of fetal well-being during labor compared with no stimulation among women with a singleton pregnancy. To study the maternal and neonatal outcomes in the two groups.

STUDY DESIGN

A randomized controlled trial undertaken in the department of Obstetrics and Gynecology at a tertiary care teaching hospital between 2014 and 2016.

INCLUSION CRITERIA

Women with a singleton pregnancy at or after 37 weeks of gestation with cephalic presentation in labor having one of the following abnormalities on fetal heart tracing - fetal heart rate less than 110 beats per minute or more than 160 beats per minute, variable decelerations, late decelerations, minimal or absent beat to beat variability.

EXCLUSION CRITERIA

women requiring an immediate cesarean section; conditions which would preclude a vaginal delivery; intrauterine fetal demise or a major fetal congenital abnormality. The women were followed in labor and randomised to either the manual stimulation group or the no stimulation group when one of the CTG abnormalities were present. In the manual stimulation group the fetus was stimulated, abdominally by holding the head in the palm of one hand when the cervical dilatation was less than 3cm or vaginally by pinching the scalp of the fetus when the cervical dilatation was ≥3cm. After delivery, cord blood sample was collected and pH estimated. Mother and baby were followed up until discharge and mode of delivery, cord blood pH at birth, Apgar score at 1 and 5 minutes, neonatal intensive care unit admissions and duration of stay were the outcomes studied. Data was entered and compiled as frequency and percent for categorical variables. For continuous variables, data was calculated using mean and standard deviation. Chi-square test was used for assessing the association between the intervention and fetal and maternal outcomes.

RESULTS

A total of 327 women were included in the trial, of whom 164 were in the manual fetal stimulation group (group 1) and 163 were in the 'no stimulation' group (group 2). The Cesarean section rates were 25.61% in group 1 and 30.67% in group 2 (p=0.308). The mean cord blood pH at birth was 7.267±0.027 in group 1 and 7.265±0.024 in group 2 (p=0.479)and Apgar score at 1 min and 5 min (p=0.169 and p=0.423 respectively between the two groups) were not found to be statistically different among the two groups.

CONCLUSION

There is no significant change in feto-maternal outcomes with manual fetal stimulation in women having non-reassuring cardiotocographic changes in labor.

Relationship Between Umbilical Cord Gas Values and Neonatal Outcomes: Implications for Electronic Fetal Heart Rate Monitoring

OBJECTIVE

To evaluate the relationship between umbilical artery cord gas values and fetal tolerance of labor, as reflected by Apgar score. We hypothesized the existence of wide biological variability in fetal tolerance of metabolic acidemia, which, if present, would weaken one fundamental assumption underlying the use of electronic fetal heart rate (FHR) monitoring.

METHODS

We conducted a retrospective cohort study of term, singleton, nonanomalous fetuses delivered in our institution between March 2012 and July 2020. Universally obtained umbilical cord gas values and Apgar scores were extracted. We calculated Spearman correlation coefficients and receiver operating characteristic curves for various levels of umbilical artery pH, base excess, and Apgar scores.

RESULTS

We analyzed data from 29,787 deliveries. The statistical correlation between umbilical artery pH and base excess and both 1- and 5-minute Apgar scores was weak or nonexistent in all pH range subgroups (range 0.064-0.213). Receiver operating characteristic curve analysis suggested umbilical artery pH value of 7.22 yields the best discrimination for prediction of a severely depressed newborn (5-minute Apgar score less than 4), but sensitivity and specificity for this predictive value remains poor to moderate.

CONCLUSION

The use of electronic FHR monitoring is predicated on a documented relationship between FHR patterns and umbilical artery pH, and an assumed correlation between pH and fetal outcomes, reflecting fetal tolerance of labor and delivery. Our data demonstrate a weak-to-absent correlation between metabolic acidemia and even short-term fetal condition, thus significantly weakening this latter assumption. No amount of future modification of FHR pattern interpretation to better predict newborn pH is likely to lead to improved newborn outcomes, given this weakness in a fundamental assumption on which FHR monitoring is based.

Fetal Heart Rate Tracing Category II: A Broad Category in Need of Stratification

Fetal heart rate (FHR) tracings are classified into 3 categories per the National Institute of Child Health and Human Development guidelines. There exists broad consensus on the recognition and management of categories I and III. However, a category II FHR tracing is considered "indeterminate" and cannot be classified as either reassuring or non-reassuring. Absence of variability and high frequency and increased depth of decelerations are the key determining factors that make a category II tracing non-reassuring and are associated with fetal metabolic acidosis. Periodic category II tracing is present in the majority of normal laboring patients. In the setting of a category II tracing, an initial attempt should be made for in utero resuscitation of the fetus. If the tracing fails to improve over a period of 1 to 2 hours, or the fetal tracing gradually deteriorates, a decision should be made for operative vaginal or cesarean delivery. Category II tracing management algorithms can aid in decision-making in this uncertain clinical scenario. Team training and simulation may improve team performance and have a positive impact on neonatal outcomes.

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.

Factors associated with intrapartum ZigZag pattern of fetal heart rate: A retrospective one-year cohort study of 5150 singleton childbirths

OBJECTIVES

Recent studies suggest that intrapartum ZigZag pattern of fetal heart rate (FHR) is significantly associated with cord blood acidaemia and neonatal complications. For the clinical significance of this pattern, it is mandatory that ZigZag episodes in cardiotocographic (CTG) recording are correctly identified. The aim of the present study was to examine maternal, fetal and delivery-related factors that could explain the occurrence of ZigZag pattern of FHR during the last 2 h of labour in a large obstetric cohort.

STUDY DESIGN

CTG recordings from 5150 singleton childbirths at ≥33 weeks of gestation during one year were evaluated retrospectively and blinded to pregnancy and neonatal outcomes in a university hospital in Helsinki, Finland. All women in the cohort were in the active phase of labour with regular uterine contractions. ZigZag FHR pattern was defined as FHR baseline amplitude changes of >25 bpm with a duration of 2-30 min. The following maternal, fetal and labour/delivery-related variables were determined: maternal age, obesity (prepregnancy BMI ≥ 30.0 kg/m²), parity, preeclampsia, maternal fever ≥38.0 °C, smoking, gestational age at delivery, fetal sex, birth weight z-score, mode of delivery, and type of onset of labour.

RESULTS

ZigZag pattern occurred in 582/5150 (11.3 %) cases, and only in childbirths after 37 weeks of gestation. Fetal male gender (OR 3.29; 95 % CI 2.70-4.02), nulliparous pregnancy (OR 2.60; 95 % CI 2.15-3.15) and post-term gestational age (≥42 weeks) (OR 1.92; 95 % CI 1.47-2.48) were independently associated with the occurrence of ZigZag pattern. Among the three significant risk factors, clustering of two or three factors was associated with an increase of the ZigZag pattern occurrence risk to 5.0-16.4-fold (95 % CI 3.16-31.60).

CONCLUSIONS

ZigZag pattern occurred in term pregnancies after 37 weeks of gestation only. Fetal male gender, nulliparity and post-term pregnancy are significantly associated with ZigZag FHR pattern during the last two hours of labour. Identification of maternal, fetal and delivery-related variables are imperative in order to interpret correctly the findings of CTG and to prevent adverse neonatal outcome.

The effect of intrapartum oxygen supplementation on category II fetal monitoring

BACKGROUND

Maternal oxygen administration is a widely used intrauterine resuscitation technique for fetuses with category II electronic fetal monitoring patterns, despite a paucity of evidence on its ability to improve electronic fetal monitoring patterns.

OBJECTIVE

This study investigated the effect of intrapartum oxygen administration on Category II electronic fetal monitoring patterns.

STUDY DESIGN

This is a secondary analysis of a randomized trial conducted in 2016-2017, in which patients with fetuses at ≥37 weeks' gestation in active labor with category II electronic fetal monitoring patterns were assigned to 10 L/min of oxygen by face mask or room air until delivery. Trained obstetrical research nurses blinded to allocation extracted electronic fetal monitoring data. The primary outcome was a composite of high-risk category II features including recurrent variable decelerations, recurrent late decelerations, prolonged decelerations, tachycardia, or minimal variability 60 minutes after randomization to room air or oxygen. Secondary outcomes included individual components of the composite high-risk category II features, resolution of recurrent decelerations within 60 minutes of randomization, and total deceleration area. The outcomes between the room air and oxygen groups were compared using univariable statistics. Time-to-event analysis was used to compare time to resolution of recurrent decelerations between the groups. Paired analysis was used to compare the pre- and postrandomization outcomes within each group.

RESULTS

All 114 randomized patients (57 room air and 57 oxygen) were included in this analysis. There was no difference in resolution of recurrent decelerations within 60 minutes between the oxygen and room air groups (75.4% vs 86.0%; P=.15). The room air and oxygen groups had similar rates of composite high-risk category II features including recurrent variable decelerations, recurrent late decelerations, prolonged decelerations, tachycardia, and minimal variability 60 minutes after randomization. Time to resolution of recurrent decelerations and total deceleration area were similar between the room air and oxygen groups. Among patients who received oxygen, there was no difference in the electronic fetal monitoring patterns pre- and postrandomization. Similar findings were observed in the electronic fetal monitoring patterns pre- and postrandomization in room air patients.

CONCLUSION

Intrapartum maternal oxygen administration for category II electronic fetal monitoring patterns did not resolve high-risk category II features or hasten the resolution of recurrent decelerations. These results suggest that oxygen administration has no impact on improving category II electronic fetal monitoring patterns.

What's new in obstetric anesthesia in 2018?

The Gerard W. Ostheimer Lecture presented at the annual meeting of the Society of Obstetric Anesthesia and Perinatology (SOAP) is a one-year summary of the literature published in domains of interest to anesthesiologists who manage and care for obstetric patients. One individual is asked to review the literature and present the lecture. This manuscript summarizes aspects of the Gerard W. Ostheimer Lecture presented at the 2019 SOAP meeting; the relevant literature from 2018 was summarized. The topics included in this review are maternal morbidity, antibiotic prophylaxis, anaphylaxis, the Lancet series on increasing cesarean delivery rates, the Robson Ten-Group Classification System, pelvic floor disorders, timing of delivery in nulliparous women, placenta accreta disorders, anesthesia for cesarean delivery, labor analgesia (including parturients with thrombocytopenia and tattoos, and epidural maintenance with the programmed intermittent epidural bolus technique), ultrasound use in obstetric anesthesia, and drugs in pregnancy.

Response to category II tracings: Does anything help?

Electronic fetal monitoring (EFM) is the most commonly used tool to screen for intrapartum fetal hypoxia. Category II EFM is present in over 80% of laboring patients and poses a unique challenge to management given the breadth of EFM features that fall within this category. Certain Category II patterns, such as recurrent late or recurrent variable decelerations, are more predictive of neonatal acidemia than others. A key feature among many published algorithms for Category II management is the use of intrauterine fetal resuscitation techniques including maternal oxygen administration, amnioinfusion, intravenous fluid bolus, discontinuation of oxytocin, and tocolytic administration. The goal of intrauterine resuscitation is to prevent or reverse fetal hypoxia. This is most likely to be successful if the etiology of the Category II EFM pattern is identified and targeted resuscitative measures are performed.

Randomized Controlled Simulation Trial to Compare Transfer Procedures for Emergency Cesarean

OBJECTIVE

To test the hypothesis that capping intravenous and epidural lines would reduce time to transfer women in labor to the operating room and time to readiness for general anesthesia for emergency cesarean. The secondary purpose was to identify latent threats to patient safety.

DESIGN

Mixed methods analysis of a randomized, controlled, in situ simulation trial.

SETTING

Labor and delivery unit at high-risk referral center.

PARTICIPANTS

Fifteen interprofessional teams that included labor and delivery nurses and anesthesiology residents.

METHODS

Immediately before simulation, we randomized bedside nurses and anesthesiology residents to one of two groups: usual transfer or the cap and run procedure. Simulation scenarios started with fetal heart rate decelerations that necessitated position changes followed by emergency cesarean. An embedded simulated obstetrician announced the decision for cesarean; completion of an OR checklist confirmed team readiness to induce general anesthesia. Postsimulation debriefing was focused on teamwork and opportunities to improve safety, and we used qualitative analysis to synthesize results.

RESULTS

We found no statistically significant difference in the overall time from decision for cesarean to readiness for general anesthesia between the two groups (usual transfer median = 445 seconds [interquartile range, 425-465] vs. cap and run 390 seconds [interquartile range, 383-443], p = .12). The time in the operating room was less in the cap and run group than in the usual transfer group (median = 300 seconds vs. 250 seconds, p = .038). Qualitative analysis of the debriefing data indicated advantages of the capping procedure, including better bed maneuverability and fewer tangled lines.

CONCLUSION

We found no evidence of decreased overall time from decision for cesarean to readiness for general anesthesia based on whether the nurse capped the intravenous and epidural lines or pushed the intravenous pole alongside the bed. However, nurses perceived improved patient safety with the cap and run procedure.

Saltatory Pattern of Fetal Heart Rate during Labor Is a Sign of Fetal Hypoxia

BACKGROUND

While late decelerations and major bradycardia episodes in intrapartum cardiotocography (CTG) recordings are known to correlate with fetal distress,little is known of the importance of the saltatory pattern.

OBJECTIVE

The aim of the study was to examine whether the fetal heart rate (FHR) saltatory pattern in intrapartum CTG registration is associated with fetal hypoxia during the last 2 h of labor.

DESIGN

The study group consisted of CTG recordings from 194 births with a 1-min Apgar score of <8 (birth weight 3,614 ± 512 g; gestational age 40.6 ± 0.7 weeks). The comparison group included 51 infants with a 1-min Apgar score of ≥9 (birth weight 3,624 ± 400 g; gestational age 40.5 ± 0.4 weeks). FHR patterns were evaluated blindly by 2 experienced perinatologists. The pH, base excess (BE), pO2 and erythropoietin (EPO) were measured from umbilical cord blood at birth as outcome variables.

RESULTS

Saltatory pattern occurred in 31/194 (16.0%) of the study group and in 1/51 (2.0%) of the comparison group. Umbilical artery pH, BE, and pO2 were lower and umbilical vein (UV) EPO higher in the study group than in the comparison group. In the study group, UV EPO level was significantly higher in cases where the saltatory pattern was present (median 241 mU/mL, 95% CI 39.4-16,484), than in those without the saltatory pattern (median 39.4 mU/mL, 95% CI 11-282) (p < 0.0001, for difference). In the study group, no differences in EPO levels were found in cases where episodes of bradycardia, tachycardia, reduced variability, or uterine tachysystole were present or absent. In the study group, saltatory pattern preceded late decelerations in 82.8%.

CONCLUSION

Saltatory pattern in an intrapartum FHR recording is an early sign of fetal hypoxia.

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.

The Fetal Reserve Index Significantly Outperforms ACOG Category System in Predicting Cord Blood Base Excess and pH: A Methodological Failure of the Category System

OBJECTIVE

Electronic fetal monitoring (EFM) has been used extensively for almost 50 years but performs poorly in predicting and preventing adverse neonatal outcome. In recent years, the current "enhanced" classification of patterns (category I-III system [CAT]) were introduced into routine practice without corroborative studies, which has resulted in even EFM experts lamenting its value. Since abnormalities of arterial cord blood parameters correlate reasonably well with risk of fetal injury, here we compare the statistical performance of EFM using the current CAT system with the Fetal Reserve Index (FRI) for predicting derangements in base excess (BE), pH, and pO₂ in arterial cord blood.

METHODS

We utilized a research database of labor data, including umbilical cord blood measurements to assess patients by both worst CAT and last FRI classifications. We compared these approaches for their ability to predict BE, pH, and pO₂ in cord blood.

RESULTS

The FRI showed a clear correlation with cord blood BE and pH with BE being more highly correlated than pH. The CAT was much less predictive than FRI (P < .05). The CAT II cases had FRI scores across the spectrum of severity of FRI designations and as such provide little clinical discrimination. The PO₂ was not discriminatory, in part, because of neonatal interventions.

CONCLUSIONS

The Fetal Reserve Index (FRI) provides superior performance over CAT classification of FHR patterns in predicting the BE and pH in umbilical cord blood. Furthermore, the CAT system fails to satisfy multiple fundamental principles required for successful screening programs. Limitations of CAT are further compounded by assumptions about physiology that are not consistent with clinical observations.