Electronic fetal heart rate monitoring and its relationship to neonatal and infant mortality in the United States

Assessing the applicability of obstetrical randomized controlled trials in real-world practices

This article examines the applicability of obstetrical randomized controlled trials (RCTs) in the real-world and proposes a classification of the value of these trials based on their potential for achieving sustainable practices. In the context of this discussion, real-world results pertain to the potential impact of the RCT on sustainable interventions and practices, and its implications for healthcare practice or policy, in the country (or countries) that was conducted. While RCTs are generally regarded as the gold standard of medical evidence, their effectiveness in producing meaningful real-world results depends, among various other factors, on the clarity and specificity of the trial definitions used for diagnosis (characteristics of the study group or enrollment criteria) and treatment (intervention). The definitions used for diagnosis and treatment, especially in pragmatic trials, can influence the likelihood for real-world implementation. By analyzing notable obstetrical RCTs, the authors find that trials with well-defined diagnoses and treatments that can be implemented without specialized expertise are more likely to generate results that are relevant to general practice, indicating higher value. In contrast, RCTs with ambiguous or undefined diagnoses and treatments often lead to variations in practice and produce unreliable real-world outcomes and practices suggesting lower value. Recognizing this variability can offer valuable guidance for the design and evaluation of RCTs in obstetrics.

Power-MF: robust fetal QRS detection from non-invasive fetal electrocardiogram recordings

Objective.Perinatal asphyxia poses a significant risk to neonatal health, necessitating accurate fetal heart rate monitoring for effective detection and management. The current gold standard, cardiotocography, has inherent limitations, highlighting the need for alternative approaches. The emerging technology of non-invasive fetal electrocardiography shows promise as a new sensing technology for fetal cardiac activity, offering potential advancements in the detection and management of perinatal asphyxia. Although algorithms for fetal QRS detection have been developed in the past, only a few of them demonstrate accurate performance in the presence of noise and artifacts.Approach.In this work, we proposePower-MF, a new algorithm for fetal QRS detection combining power spectral density and matched filter techniques. We benchmarkPower-MFagainst three open-source algorithms on two recently published datasets (Abdominal and Direct Fetal ECG Database: ADFECG, subsets B1 Pregnancy and B2 Labour; Non-invasive Multimodal Foetal ECG-Doppler Dataset for Antenatal Cardiology Research: NInFEA).Main results.Our results show thatPower-MFoutperforms state-of-the-art algorithms on ADFECG (B1 Pregnancy: 99.5% ± 0.5% F1-score, B2 Labour: 98.0% ± 3.0% F1-score) and on NInFEA in three of six electrode configurations by being more robust against noise.Significance.Through this work, we contribute to improving the accuracy and reliability of fetal cardiac monitoring, an essential step toward early detection of perinatal asphyxia with the long-term goal of reducing costs and making prenatal care more accessible.

A comparative study of CTG monitoring one hour before labor in infants born with and without asphyxia

BACKGROUND AND AIM

Asphyxia is a condition arising when the infant is deprived of oxygen, causing Fetal brain damage or death, which is associated with hypoxia and hypercapnia. Although fetal Cardiotocography (CTG) can show the Fetal health status during labor, some studies have reported cases of fetal asphyxia despite reassuring CTGs. This study hence aimed to compare FHR Monitoring and uterine contractions in the last hour before delivered between two groups of infants born with and without asphyxia.

METHODOLOGY

The study was conducted on 70 pregnant women who delivered Taleghani and Al-Zahra academic teaching hospitals of Tabriz for labor in 2020-2021.

RESULTS

The study data showed no significant difference between mothers of infants with and without asphyxia in terms of demographics (p > 0.05). The prevalence of asphyxia was significantly higher only in mothers with the gravidity of 3 and 4 (p = 0.003). In terms of the methods for labor induction, the use of oxytocin was more common among mothers of infants with asphyxia (74.3%) than in those of infants without asphyxia (p = 0.015). The results also revealed a significant difference between infants with and without asphyxia in the Apgar score (first, fifth, and tenth minutes), need for neonatal resuscitation, umbilical cord artery Acidosis (pH, bicarbonate, and BE), and severity of HIE between two groups of infants with asphyxia and without asphyxia (p < 0.0001). The comparison of fetal CTG 0 to 20 min before the delivery indicated that normal variability was observed in 71.4% of infants born with asphyxia, whereas this figure for infants born without asphyxia was 91.4% (p = 0.031). However, the results showed no significant difference between the two groups of infants in any of the tstudied indicators at 20 and 40 min before the labor(p > 0.05). There was a significant difference between the two groups of infants in terms of deceleration at 40 and 60 min before the labor, as it was observed in 53.6% of infants born with asphyxia and only 11.1% of those born without asphyxia. The results also demonstrated a significant difference between the two groups in the type of deceleration (p = 0.025). Pearson and Spearman correlation coefficients showed a significant and direct relationship between interpretation the CTG of the three Perinatologists(p < 0.0001, r > 0.8).

CONCLUSION

The study results demonstrated a significant difference between infants born with asphyxia and those born without asphyxia in variability at 0 to 20 min before the labor and deceleration at 40 to 60 min before the labor.

The relationship between maternal anemia and electronic fetal monitoring patterns

BACKGROUND

Anemia is a commonly diagnosed comorbidity in pregnancy that is associated with increased risk of maternal and neonatal complications. Recent data demonstrate that maternal anemia is associated with higher umbilical artery and umbilical vein O2 content at the time of delivery.

OBJECTIVE

This study aimed to examine the relationship between maternal anemia and electronic fetal monitoring patterns associated with fetal hypoxia.

STUDY DESIGN

This is a secondary analysis of a prospective cohort study of singleton term deliveries with cord gases and universal complete blood count collected on admission between 2010 and 2014. Maternal anemia was defined as hemoglobin ≤11.0 g/dL on admission. The primary outcome was a composite of high-risk category 2 electronic fetal monitoring features in the last 60 minutes before delivery (recurrent late and/or variable decelerations, minimal variability, tachycardia, or >1 prolonged deceleration); secondary outcomes were total deceleration area and total deceleration area >90th percentile. Of the 8580 patients in the original study, 8196 were included in the analysis. Outcomes were compared between patients with and without anemia. Multivariable logistic regression was used to adjust for potentially confounding factors, including hypertensive disorders of pregnancy and induction of labor.

RESULTS

Of the 8196 patients with complete blood count on admission and fetal monitoring data, 2672 (32.6%; 2672/8196) were anemic and 5524 (67.4%; 5524/8196) were not. Patients with anemia were significantly less likely to have composite high-risk category 2 features on electronic fetal monitoring (34.2% vs 32.0%; adjusted risk ratio, 0.93; 95% confidence interval, 0.86-0.99). Women with anemia also had decreased total deceleration area and were less likely to have total deceleration area >90th percentile (18.7% vs 16.2%; adjusted risk ratio, 0.85; 95% confidence interval, 0.77-0.94).

CONCLUSION

Patients with anemia are less likely to have high-risk category 2 electronic fetal monitoring features associated with fetal hypoxia. This finding is consistent with the association between maternal anemia and increased umbilical cord O2 content, and suggests that maternal anemia may be protective against intrapartum fetal hypoxia.

Three-tiered fetal heart rate interpretation system and adverse neonatal and maternal outcomes: a systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the rate of adverse neonatal or maternal outcomes in parturients with fetal heart rate tracings categorized as I, II or, III within the last 30 to 120 minutes of delivery.

DATA SOURCES

The MEDLINE Ovid, Scopus, Embase, CINAHL, and Clinicaltrials.gov databases were searched electronically up to May 2022, using combinations of the relevant medical subject heading terms, keywords, and word variants that were considered suitable for the topic.

STUDY ELIGIBILITY CRITERIA

Only observational studies of term infants reporting outcomes of interest with category I, II, or III fetal heart rate tracings were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

The coprimary outcome was the rate of either Apgar score <7 at 5 minutes or umbilical artery pH <7.00. Secondary outcomes were divided into neonatal and maternal adverse outcomes. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale. Random-effect meta-analyses of proportions were used to estimate the pooled rates of each categorical outcome in fetal heart rate tracing category I, II, and III patterns, and random-effect head-to-head meta-analyses were used to directly compare fetal heart rate tracings category I vs II and fetal heart rate tracing category II vs III, expressing the results as summary odds ratio or as mean differences with relative 95% confidence intervals.

RESULTS

Of the 671 articles reviewed, 3 publications met the inclusion criteria. Among them were 47,648 singletons at ≥37 weeks' gestation. Fetal heart rate tracings in the last 30 to 120 minutes before delivery were characterized in the following manner: 27.0% of deliveries had category I tracings, 72.9% had category II tracings, and 0.1% had category III tracings. A single study, which was rated to be of poor quality, contributed 82.1% of the data and it did not provide any data for category III fetal heart rate tracings. When compared with category I fetal heart rate tracings (0.74%), the incidence of an Apgar score <7 at 5 minutes were significantly higher among deliveries with category II fetal heart rate tracings (1.51%) (odds ratio, 1.56; 95% confidence interval, 1.23-1.99) and among those with category III tracings (14.63%) (odds ratio, 14.46; 95% confidence interval, 2.77-75.39). When compared with category II tracings, category III tracings also had a significantly higher likelihood of a low Apgar score at 5 minutes (odds ratio, 14.46; 95% confidence interval, 2.77-75.39). The incidence of an umbilical artery pH <7.00 were similar among those with category I and those with category II tracings (0.08% vs 0.24%; odds ratio, 2.85; 95% confidence interval, 0.41-19.55). When compared with category I tracings, the incidence of an umbilical artery pH <7.00 was significantly more common among those with category III tracings (31.04%; odds ratio, 161.56; 95% confidence interval, 25.18-1036.42); likewise, when compared with those with category II tracings, those with category III tracings had a significantly higher likelihood of having an umbilical artery pH <7.00 (odds ratio, 42.29; 95% confidence interval, 14.29-125.10). Hypoxic-ischemic encephalopathy occurred with similar frequency among those with categories I and those with category II tracings (0 vs 0.81%; odds ratio, 5.86; 95% confidence interval, 0.75-45.89) but was significantly more common among those with category III tracings (0 vs 18.97%; odds ratio, 61.43; 95% confidence interval, 7.49-503.50). Cesarean delivery occurred with similar frequency among those with category I (13.41%) and those with category II tracings (11.92%) (odds ratio, 0.87; 95% confidence interval, 0.72-1.05) but was significantly more common among those with with category III tracings (14.28%) (odds ratio, 3.97; 95% confidence interval, 1.62-9.75). When compared with those with category II tracings, cesarean delivery was more common among those with category III tracings (odds ratio, 4.55; 95% confidence interval, 1.88-11.01).

CONCLUSION

Although the incidence of an Apgar score <7 at 5 minutes and umbilical artery pH <7.00 increased significantly with increasing fetal heart rate tracing category, about 98% of newborns with category II tracings do not have these adverse outcomes. The 3-tiered fetal heart rate tracing interpretation system provides an approximate but imprecise measurement of neonatal prognosis.

Intrapartum electronic fetal monitoring features associated with a clinical diagnosis of nonreassuring fetal status

BACKGROUND

Nonreassuring fetal status detected by continuous electronic fetal monitoring accounts for almost 1 in 4 primary cesarean deliveries. However, given the subjective nature of the diagnosis, there is a need to identify the electronic fetal monitoring patterns that are clinically considered nonreassuring.

OBJECTIVE

This study aimed to describe which electronic fetal monitoring features are most commonly associated with first-stage cesarean delivery for nonreassuring fetal status, and to evaluate the risk of neonatal acidemia following cesarean delivery for nonreassuring fetal status.

STUDY DESIGN

This was a nested case-control study in a prospectively collected cohort of patients with singleton pregnancies at ≥37 weeks' gestation, admitted in spontaneous labor or for induction of labor from 2010 to 2014 at a single tertiary care center. Patients with preterm pregnancies, multiple gestations, planned cesarean delivery, or nonreassuring fetal status in the second stage of labor were excluded. Cases were identified as having nonreassuring fetal status on the basis of what was documented in the operative note by the delivering physician. Controls were patients without nonreassuring fetal status within 1 hour of delivery. Cases were matched to controls in a 1:2 ratio by parity, obesity, and history of cesarean delivery. Electronic fetal monitoring data were abstracted by credentialed obstetrical research nurses for the 60 minutes before delivery. The primary exposure of interest was the incidence of high-risk category II electronic fetal monitoring features in the 60 minutes before delivery; in particular, the incidence of minimal variability, recurrent late decelerations, recurrent variable decelerations, tachycardia, and >1 prolonged deceleration were compared between groups. We also compared neonatal outcomes between cases and controls, including fetal acidemia (umbilical artery pH <7.1), other umbilical artery gas analytes, and neonatal and maternal outcomes.

RESULTS

Of the 8580 patients in the parent study, 714 (8.3%) underwent cesarean delivery for nonreassuring fetal status in the first stage of labor. Patients diagnosed with nonreassuring fetal status requiring cesarean delivery were more likely to have recurrent late decelerations, >1 prolonged deceleration, and recurrent variable decelerations compared with controls. More than 1 prolonged deceleration was associated with 6 times increased rate of nonreassuring fetal status diagnosis resulting in cesarean delivery (adjusted odds ratio, 6.73 [95% confidence interval, 2.47-8.33]). Rates of fetal tachycardia were similar between groups. Minimal variability was less common in the nonreassuring fetal status group compared with controls (adjusted odds ratio, 0.36 [95% confidence interval, 0.25-0.54]). Compared with control deliveries, cesarean delivery for nonreassuring fetal status was associated with nearly 7 times higher risk of neonatal acidemia (7.2% vs 1.1%; adjusted odds ratio, 6.93 [95% confidence interval, 3.83-12.54]). Composite neonatal morbidity and composite maternal morbidity were more likely among patients delivered for nonreassuring fetal status in the first stage (3.9% vs 1.1%; adjusted odds ratio, 5.70 [2.60-12.49]; and 13.3% vs 8.0%; adjusted odds ratio, 1.99 [1.41-2.80]).

CONCLUSION

Although multiple category II electronic fetal monitoring features have been traditionally linked to acidemia, the presence of recurrent late decelerations, recurrent variable decelerations, and prolonged decelerations seemed to concern obstetricians enough to surgically intervene for nonreassuring fetal status. A clinical intrapartum diagnosis of nonreassuring fetal status in the setting of these electronic fetal monitoring features is also associated with increased risk of acidemia, suggesting clinical validity to the diagnosis of nonreassuring fetal status.

Evaluation of fetal acidemia during delivery using the conventional 5-tier classification and Rainbow systems

The association between prepartum time-series fetal heart rate pattern changes and cord blood gas data at delivery was examined using the conventional 5-tier classification and the Rainbow system for 229 female patients who delivered vaginally. They were classified into three groups based on the results of umbilical cord blood gas analysis at delivery. The fetal heart rate pattern classifications were based on analysis of measurement taken at 10-min intervals, beginning at 120 min pre-delivery. The relationship between fetal heart rate pattern classification and cord blood pH at delivery changed over time. The 5-tier classification at each interval increased before delivery in the Mild and Severe groups compared with the Normal group. No significant differences were observed between acidemia groups. The Rainbow classification showed a significant differences between the acidemia groups at each interval, particularly during the prepartum period. A relationship between classification and outcome was evident before delivery for both the 5-tier classification and Rainbow system.

Association between marked fetal heart rate variability and neonatal acidosis: A prospective cohort study

OBJECTIVE

To assess the association between marked variability in fetal heart rate (FHR) and neonatal acidosis.

DESIGN

Bicentric prospective cohort study.

SETTING

From January 2019 to December 2019, in two French tertiary care maternity units.

POPULATION

Women in labour at ≥37 weeks of gestation, with continuous FHR monitoring until delivery and with the availability of umbilical arterial pH. Women with intrauterine fetal death or medical termination, multiple pregnancies, non-cephalic presentation or planned caesarean delivery were excluded.

METHODS

The exposure was marked variability in FHR in the 60 minutes before delivery, defined as a variability greater than 25 beats per minute, with a minimum duration of 1 minute. To assess the association between marked variability and neonatal acidosis, we used multivariable modified Poisson regression modelling. We then conducted subgroup analyses according to the US National Institute of Child Health and Human Development (NICHD) category of the associated fetal heart rate.

MAIN OUTCOME MEASURES

Neonatal acidosis, defined as an umbilical artery pH of ≤7.10.

RESULTS

Among the 4394 women included, 177 (4%) had marked variability in fetal heart rate in the 60 minutes before delivery. Acidosis occurred in 6.0% (265/4394) of the neonates. In the multivariable analysis, marked variability was significantly associated with neonatal acidosis (aRR 2.30, 95% CI 1.53-3.44). In subgroup analyses, the association between marked variability and neonatal acidosis remained significant in NICHD category-I and category-II groups.

CONCLUSIONS

Marked variability was associated with a twofold increased risk of neonatal acidosis.

Accuracy of intrapartum cardiotocography in identifying fetal acidemia by umbilical cord blood analysis in low-risk pregnancies

OBJECTIVE

The aim of this study was to evaluate the accuracy of intrapartum cardiotocography in identifying fetal acidemia by umbilical cord blood analysis in low-risk pregnancies.

METHODS

This is a retrospective cohort study of low-risk singleton pregnancies in labor after performing intrapartum cardiotocography categories I, II, and III. The presence of fetal acidemia at birth was identified by analyzing the pH of umbilical cord arterial blood (pH<7.1).

RESULTS

No significant effect of the cardiotocography category on the arterial (p=0.543) and venous (p=0.770) pH of umbilical cord blood was observed. No significant association was observed between the cardiotocography category and the presence of fetal acidemia (p=0.706), 1-min Apgar score <7 (p=0.260), hospitalization in the neonatal intensive care unit (p=0.605), newborn death within the first 48 h, need for neonatal resuscitation (p=0.637), and adverse perinatal outcomes (p=0.373). Sensitivities of 62, 31, and 6.0%; positive predictive values of 11.0, 16.0, and 10.0%; and negative predictive values of 85, 89.0, and 87.0% were observed for cardiotocography categories I, II, and III, respectively.

CONCLUSION

The three categories of intrapartum cardiotocography presented low sensitivities and high negative predictive values to identify fetal acidemia at birth in low-risk pregnancies.

Disquiet concerning cesarean birth

Cesarean birth has increased substantially in many parts of the world over recent decades and concerns have been raised about the propriety of this change in obstetric practice. Sometimes, a cesarean is necessary to preserve fetal and maternal health. But in balancing the risks of surgical intervention the implicit assumption has been that cesarean birth is an equivalent alternative to vaginal birth from the standpoint of the immediate and long-term health of the fetus and neonate. Increasingly, we realize this is not necessarily so. Delivery mode per se may influence short-term and abiding problems with homeostasis in offspring, quite independent of the indications for the delivery and other potentially confounding factors. The probability of developing various disorders, including respiratory compromise, obesity, immune dysfunction, and neurobehavioral disorders has been shown in some studies to be higher among individuals born by cesarean. Moreover, many of these adverse effects are not confined to the neonatal period and may develop over many years. Although the associations between delivery mode and long-term health are persuasive, their pathogenesis and causality remain uncertain. Full exploration and a clear understanding of these relationships is of great importance to the health of offspring.

Pulmonary Resilience: Moderating the Association between Oxygen Exposure and Pulmonary Outcomes in Extremely Preterm Newborns

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of infancy associated with high morbidity and mortality. Although most prevalent following extremely preterm birth, BPD is diagnosed at 36 weeks post-menstrual age, when the disease trajectory is underway, and long-term physiological implications may be irreversible. There is an urgent and unmet need to identify how early exposures can be modified to decrease the risk of developing BPD before disease progression becomes irreversible. Extremely preterm newborns encounter a paradox at birth: oxygen is a life-sustaining component of ex utero life yet is undeniably toxic. Attempts at minimizing supplemental oxygen exposure by targeting lower oxygen saturations appear to decrease BPD but may increase mortality. Given the potential association between lower oxygen saturations and increased mortality, practice guidelines favor targeting higher saturations. This uniformly increases oxygen exposure, prompting a cascade of pathogenic mechanisms implicated in BPD development. In this review, we introduce the concept of pulmonary resilience: a homeostatic process driven by the autonomic nervous system (ANS) as a moderator of physiologic stress that when functional, could inform successful environmental adaptation following extremely preterm birth. We hypothesize that infants with early-life ANS dysfunction require a higher oxygen dose for survival; conversely, oxygen exposure could be safely limited in infants with more robust early-life ANS function, an indicator of pulmonary resilience. Characterizing the pulmonary resilience continuum to guide individualized supplemental oxygen dosing may reduce morbidity and mortality in this growing population of extremely preterm infants at risk for BPD.

Identification of Hypoxia-Ischemia by chemometrics considering systemic changes of the physiology

Perinatal asphyxia represents a major medical disorder and is related to around a fourth of all neonatal deaths worldwide. Specific thresholds for lactate or pH levels define the gold standard for detecting hypoxic-ischemic events as physiological abnormalities. In contrast to current gold standard, we analyze the systemic picture, represented by the whole set of biochemical parameters from blood gas analysis, by multiparametric machine learning algorithms. In a swine model with 22 objects, we investigate the impact of neonatal hypoxic-ischemic encephalopathy on 18 individual physiological parameters. In a first approach, we study the statistical significance of individual parameters by univariate analysis methods. In a second approach, we take the most relevant parameters as input for the development of predictive models by different hybrid and non hybrid classification algorithms. The predictive power of our multiparametric models outperforms by far the limited performance of pH and lactate as reliable indicators, despite strong correlation with hypoxic-ischemic events. We have been able to detect hypoxic-ischemic events even one hour after the episode, with accuracies close to 100% in contrast to pH or lactate-based diagnosis with 62% and 78%, respectively. By all machine learning algorithms, lactate is recognized as the main contributor due to its longer-term evidence of hypoxia-ischemia episodes. However, substantial improvement of the diagnosis is achieved by predictions based on a systemic picture of different physiological parameters. Our results prove the potential applicability of our method as a support tool for decision-making that will allow obstetricians to identify hypoxic ischemic episodes more accurately during labor.

A novel algorithm based on ensemble empirical mode decomposition for non-invasive fetal ECG extraction

Non-invasive fetal electrocardiography appears to be one of the most promising fetal monitoring techniques during pregnancy and delivery nowadays. This method is based on recording electrical potentials produced by the fetal heart from the surface of the maternal abdomen. Unfortunately, in addition to the useful fetal electrocardiographic signal, there are other interference signals in the abdominal recording that need to be filtered. The biggest challenge in designing filtration methods is the suppression of the maternal electrocardiographic signal. This study focuses on the extraction of fetal electrocardiographic signal from abdominal recordings using a combination of independent component analysis, recursive least squares, and ensemble empirical mode decomposition. The method was tested on two databases, the Fetal Electrocardiograms, Direct and Abdominal with Reference Heartbeats Annotations and the PhysioNet Challenge 2013 database. The evaluation was performed by the assessment of the accuracy of fetal QRS complexes detection and the quality of fetal heart rate determination. The effectiveness of the method was measured by means of the statistical parameters as accuracy, sensitivity, positive predictive value, and F1-score. Using the proposed method, when testing on the Fetal Electrocardiograms, Direct and Abdominal with Reference Heartbeats Annotations database, accuracy higher than 80% was achieved for 11 out of 12 recordings with an average value of accuracy 92.75% [95% confidence interval: 91.19-93.88%], sensitivity 95.09% [95% confidence interval: 93.68-96.03%], positive predictive value 96.36% [95% confidence interval: 95.05-97.17%] and F1-score 95.69% [95% confidence interval: 94.83-96.35%]. When testing on the Physionet Challenge 2013 database, accuracy higher than 80% was achieved for 17 out of 25 recordings with an average value of accuracy 78.24% [95% confidence interval: 73.44-81.85%], sensitivity 81.79% [95% confidence interval: 76.59-85.43%], positive predictive value 87.16% [95% confidence interval: 81.95-90.35%] and F1-score 84.08% [95% confidence interval: 80.75-86.64%]. Moreover, the non-invasive ST segment analysis was carried out on the records from the Fetal Electrocardiograms, Direct and Abdominal with Reference Heartbeats Annotations database and achieved high accuracy in 7 from in total of 12 records (mean values μ < 0.1 and values of ±1.96σ < 0.1).

A Machine Learning Approach to Monitor the Emergence of Late Intrauterine Growth Restriction

Late intrauterine growth restriction (IUGR) is a fetal pathological condition characterized by chronic hypoxia secondary to placental insufficiency, resulting in an abnormal rate of fetal growth. This pathology has been associated with increased fetal and neonatal morbidity and mortality. In standard clinical practice, late IUGR diagnosis can only be suspected in the third trimester and ultimately confirmed at birth. This study presents a radial basis function support vector machine (RBF-SVM) classification based on quantitative features extracted from fetal heart rate (FHR) signals acquired using routine cardiotocography (CTG) in a population of 160 healthy and 102 late IUGR fetuses. First, the individual performance of each time, frequency, and nonlinear feature was tested. To improve the unsatisfactory results of univariate analysis we firstly adopted a Recursive Feature Elimination approach to select the best subset of FHR-based parameters contributing to the discrimination of healthy vs. late IUGR fetuses. A fine tuning of the RBF-SVM model parameters resulted in a satisfactory classification performance in the training set (accuracy 0.93, sensitivity 0.93, specificity 0.84). Comparable results were obtained when applying the model on a totally independent testing set. This investigation supports the use of a multivariate approach for the in utero identification of late IUGR condition based on quantitative FHR features encompassing different domains. The proposed model allows describing the relationships among features beyond the traditional linear approaches, thus improving the classification performance. This framework has the potential to be proposed as a screening tool for the identification of late IUGR fetuses.

Impaired validity of the new FIGO and Swedish CTG classification templates to identify fetal acidosis in the first stage of labor

INTRODUCTION

Cardiotocography (CTG) is the main method of intrapartum fetal surveillance. In 2015 a new guideline was introduced by the International Federation of Gynecology and Obstetrics (FIGO), FIGO-15. In Sweden it was adjusted to SWE-17, replacing the previous national template, SWE-09. This study, conducted at one university hospital and one regional hospital in southern Sweden, evaluated the diagnostic validity of these three templates to detect fetal acidosis during the first stage of labor.

MATERIAL AND METHODS

A total of 73 neonates with pH <7.1 in umbilical cord artery or vein at cesarean delivery during the first stage of labor were identified retrospectively. For each acidotic neonate, three non-acidemic neonates, with a pH ≥7.2 in cord artery and vein, and Apgar scores ≥9 at five and ten minutes, in all 219 neonates, were selected. The CTG tracings before birth in acidemic neonates, and tracings at the same cervical dilatation in the non-acidemic neonates, were independently assessed by three professionals from the obstetric staff, blinded to group and clinical data. Based on their categorizations of the included variables (baseline, variability, accelerations, decelerations and contraction rate), each CTG tracing was systematically classified according to the three templates. The sensitivity and specificity to identify acidemia by the classification pathological were determined for each template. Interobserver agreement in the assessments of tracings as pathological or not was analyzed, using free-marginal Kappa index.

RESULTS

The sensitivity for patterns classified as pathological to identify acidemia was similar for FIGO-15 (71%) and SWE-17 (77%, p = .13), and the specificity was 97% for both. SWE-09 had a significantly higher sensitivity (95%, p < .001) albeit with a lower specificity (90%, p < .001) than the other two templates. Among acidemic neonates, the fraction of tracings classified as normal was higher with SWE-17 (9.6%) than with SWE-09 (0%; p = .01) and FIGO-15 (1.4%; p = .06). For tracings from neonates with acidemia, agreement for three independent assessors was strong (κ 0.85) with SWE-09, and weak for FIGO-15 (κ 0.47), and SWE-17 (κ 0.51). For tracings from neonates without acidemia, the agreement was almost perfect for FIGO-15 (κ 0.91), strong withSWE-17 (κ 0.90) and moderate with SWE-09 (κ 0.78).

CONCLUSIONS

The ability of FIGO-15 and SWE-17 to identify fetal acidosis is considered insufficient. The combination of a high sensitivity and a high specificity makes SWE-09 the most discriminatory template during the first stage of labor.

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.

Prolonged Fetal Heart Rate Decelerations in Labor: Can We Reduce Unplanned Primary Cesarean Sections in This Group?

INTRODUCTION

Non-reassuring fetal tracing is the second leading cause of primary cesarean delivery in the United States. Prolonged fetal heart rate decelerations are non-reassuring fetal heart rate characteristics, which do not uniformly predict poor fetal outcome but can prompt obstetricians to proceed with cesarean delivery. The objective of this manuscript is to identify a strategy to reduce the primary cesarean section rate in patients with prolonged fetal heart rate decelerations in labor.

METHODS

This is a retrospective cohort study over a 5-year period at an academic medical center, including patients undergoing primary cesarean section following labor induction, augmentation, or spontaneous labor who were noted to have prolonged fetal heart rate deceleration(s) in the 1 h prior to the time of delivery. Two groups were compared: "crash" cesarean sections versus "emergent" cesarean sections. The primary outcome was if fetal heart tones were rechecked in the operating room prior to cesarean section incision. Secondary outcomes included maternal-fetal monitoring versus Doppler fetal heart tones in the operating room, return to baseline noted in the operating room, fetal outcomes, fetal monitoring characteristics, and anesthesia type between crash versus emergent groups.

RESULTS

Of 1969 term singleton cesarean sections, 119 patients met our inclusion criteria (emergent group n = 80) (crash group n = 39), which accounted for 13.9% of all primary cesarean sections during the study period. The emergent group had a significantly higher rate of reassessment of fetal heart tones in the operating room n = 61 (76.2%) versus the crash group n = 15 (38.4%) (p ≤ 0.0001). There were no statistically significant differences regarding fetal outcomes between the two groups. The crash group had a higher rate of category 1 fetal heart rate tracing prior to the prolonged deceleration, a longer median prolonged deceleration, and a deeper median nadir of the prolonged deceleration; these differences were statistically significant. The prolonged-to-delivery interval was significantly shorter in the crash group (median = 15 min) than tin he emergent group (median = 33 min) (p ≤ 0.0001). The crash group also had a higher rate of general anesthesia (n = 11, 28.2%) than the emergent group (n = 6, 7.5%) (p = 0.002). The crash group was specifically investigated. Of the 15 patients with fetal heart tones rechecked in the crash group, 7 had returned to baseline in the operating room, but underwent cesarean section without fetal monitoring.

CONCLUSION

Our results indicate that the practice of placing patients on fetal monitor upon arrival to the operating room prior to performing crash cesarean delivery could reduce the rate of primary cesarean deliveries performed for prolonged decelerations in labor. When fetal heart tones have returned to baseline upon arrival in the operating room, the decision to proceed with cesarean delivery can be reconsidered. However, many clinical factors must be taken into consideration, and the decision to proceed is ultimately at the discretion of the obstetrics provider.

Evaluation of an external fetal electrocardiogram monitoring system: a randomized controlled trial

OBJECTIVE

The objective of the study was to compare interpretability of 2 intrapartum abdominal fetal heart rate-monitoring strategies. We hypothesized that an external fetal electrocardiography monitoring system, a newer technology using wireless abdominal pads, would generate more interpretable fetal heart rate data compared with standard external Doppler fetal heart rate monitoring (standard external monitoring).

STUDY DESIGN

We conducted a randomized controlled trial at 4 Utah hospitals. Patients were enrolled at labor admission and randomized in blocks based on body mass index to fetal electrocardiography or standard external monitoring. Two reviewers, blinded to study allocation, reviewed each fetal heart rate tracing. The primary outcome was the percentage of interpretable minutes of fetal heart rate tracing. An interpretable minute was defined as >25% fetal heart rate data present and no more than 25% continuous missing fetal heart rate data or artifact present. Secondary outcomes included the percentage of interpretable minutes of fetal heart rate tracing obtained while on study device only, the number of device adjustments required intrapartum, clinical outcomes, and patient/provider device satisfaction. We determined that 100 patients per arm (200 total) would be needed to detect a 5% difference in interpretability with 95% power.

RESULTS

A total of 218 women were randomized, 108 to fetal electrocardiography and 110 to standard external monitoring. Device setup failure occurred more often in the fetal electrocardiography group (7.5% [8 of 107] vs 0% [0 of 109] for standard external monitoring). There were no differences in the percentage of interpretable tracing between the 2 groups. However, fetal electrocardiography produced more interpretable fetal heart rate tracing in subjects with a body mass index ≥30 kg/m². When considering the percentage of interpretable minutes of fetal heart rate tracing while on study device only, fetal electrocardiography outperformed standard external monitoring for all subjects, regardless of maternal body mass index. Maternal demographics and clinical outcomes were similar between arms. In the fetal electrocardiography group, more device changes occurred compared with standard external monitoring (51% vs 39%), but there were fewer nursing device adjustments (2.9 vs 6.2 mean adjustments intrapartum, P < .01). There were no differences in physician device satisfaction scores between groups, but fetal electrocardiography generated higher patient satisfaction scores.

CONCLUSION

Fetal electrocardiography performed similarly to standard external monitoring when considering percentage of interpretable tracing generated in labor. Furthermore, patients reported overall greater satisfaction with fetal electrocardiography in labor. Fetal electrocardiography may be particularly useful in patients with a body mass index ≥30 kg/m².

Evaluation of 3-tier and 5-tier FHR pattern classifications using umbilical blood pH and base excess at delivery

OBJECTIVE

The relevance between time-series fetal heart rate (FHR) pattern changes during labor and outcomes such as arterial blood gas data at delivery has not been studied. Using 3-tier and 5-tier classification systems, we studied the relationship between time-series FHR pattern changes before delivery and umbilical artery blood gas data at delivery.

METHODS

The subjects were 1,909 low-risk women with vaginal delivery (age: 29.1 ± 4.4 years, parity: 1.7 ± 0.8). FHR patterns were classified by a skilled obstetrician based on each 10 min-segment of the last 60 min before delivery from continuous CTG records in an obstetric clinic.

RESULTS

The relationship between each 10 min-segment FHR pattern classification from 60 minutes before delivery and umbilical artery blood pH and base excess (BE) values at delivery changed with time. In the 3-tier classification, mean pH of Category I group in each 10 min-segment was significantly higher than that of Category II group. For Category I groups in each 10-minute segment, its number decreased and its average pH increased as the delivery time approached. In the 5-tier classification, there was the same tendency. About each level group in 10 min-segment, the higher the level, the lower the blood gas values, and mean pH of higher level groups decreased as the delivery time approached.

CONCLUSIONS

The relationship between classifications and outcomes was clear at any time from 60 min before delivery in 3- and 5-tier classifications, and the 5-tier classification was more relevant.

Fetal electrocardiography ST-segment analysis for intrapartum monitoring: a critical appraisal of conflicting evidence and a way forward

BACKGROUND

In the past century, some areas of obstetric including intrapartum care have been slow to benefit from the dramatic advances in technology and medical care. Although fetal heart rate monitoring (cardiotocography) became available a half century ago, its interpretation often differs between institutions and countries, its diagnostic accuracy needs improvement, and a technology to help reduce the unnecessary obstetric interventions that have accompanied the cardiotocography is urgently needed.

STUDY DESIGN

During the second half of the 20th century, key findings in animal experiments captured the close relationship between myocardial glycogenolysis, myocardial workload, and ST changes, thus demonstrating that ST waveform analysis of the fetal electrocardiogram can provide information on oxygenation of the fetal myocardium and establishing the physiological basis for the use of electrocardiogram in intrapartum fetal surveillance.

RESULTS

Six randomized controlled trials, 10 meta-analyses, and more than 20 observational studies have evaluated the technology developed based on this principle. Nonetheless, despite this intensive assessment, differences in study protocols, inclusion criteria, enrollment rates, clinical guidelines, use of fetal blood sampling, and definitions of key outcome parameters, as well as inconsistencies in randomized controlled trial data handling and statistical methodology, have made this voluminous evidence difficult to interpret. Enormous resources spent on randomized controlled trials have failed to guarantee the generalizability of their results to other settings or their ability to reflect everyday clinical practice.

CONCLUSION

The latest meta-analysis used revised data from primary randomized controlled trials and data from the largest randomized controlled trials from the United States to demonstrate a significant reduction of metabolic acidosis rates by 36% (odds ratio, 0.64; 95% confidence interval, 0.46-0.88) and operative vaginal delivery rates by 8% (relative risk, 0.92; 95% confidence interval, 0.86-0.99), compared with cardiotocography alone.

Knowledge levels of midwives regarding the interpretation of cardiotocographs at labour units in KwaZulu-Natal public hospitals

BACKGROUND

The primary purpose of cardiotocography is to detect early signs of intrapartum hypoxia and improve foetal outcomes. Intrapartum hypoxia remains the major cause of perinatal deaths during monitored labours. This is attributed to the midwives' lack of knowledge and skills in the foetal implementation and interpretation of cardiotocographs.

OBJECTIVES

This study aimed to establish midwives' knowledge and interpretive skills of cardiotocography.

METHOD

The study employed a quantitative research approach with an explorative, descriptive, cross-sectional design. A total of 226 purposively selected participants were asked to complete a self-administered, structured questionnaire, of which 125 responded by completing the questionnaire. The study was conducted in labour wards in KwaZulu-Natal public hospitals in 2014. Data analysis was performed by means of descriptive and inferential statistics using analysis of variance.

RESULTS

The findings revealed that the midwives in KwaZulu-Natal public hospitals were found to be clinically lacking in knowledge of cardiotocography.

CONCLUSION

The limited cardiotocographic knowledge of the midwives in KwaZulu-Natal public hospitals was possibly because of a lack of in-service training, as more than half of the participants (70%) indicated a need for this.

Significant reduction in umbilical artery metabolic acidosis after implementation of intrapartum ST waveform analysis of the fetal electrocardiogram

BACKGROUND

Although the evidence regarding the benefit of using ST waveform analysis of the fetal electrocardiogram is conflicting, ST waveform analysis is considered as adjunct to identify fetuses at risk for asphyxia in our center. Most randomized controlled trials and meta-analyses have not shown a significant decrease in umbilical metabolic acidosis, while some observational studies have shown a gradual decrease of this outcome over a longer period of time. Observational studies can give more insight into the effect of implementation of the ST technology in daily clinical practice.

OBJECTIVE

To evaluate the change in frequency of perinatal intervention and adverse neonatal outcome after the implementation of ST waveform analysis of the fetal electrocardiogram from 2000 to 2013.

STUDY DESIGN

This retrospective longitudinal study was conducted in a tertiary referral center. A total of 19,664 medium- and high-risk singleton pregnancies with fetuses in cephalic presentation, a gestational age of ≥36 weeks, and the intention to deliver vaginally were included. ST waveform analysis of the fetal electrocardiogram was implemented in the year 2000 and by 2010 all deliveries were monitored using this technology. Data were collected on the following perinatal outcomes: fetal blood sampling, mode of delivery, umbilical cord blood gases, Apgar scores, neonatal encephalopathy, and perinatal death. Longitudinal trend analysis was used to detect changes over time in all deliveries monitored by cardiotocography either alone or in adjunct to ST waveform analysis of the fetal electrocardiogram. Logistic regression was used to correct for possible confounders.

RESULTS

The umbilical artery metabolic acidosis rate declined from 2.5% (average rate of 2000 + 2001 + 2002) to 0.4% (average of 2011 + 2012 + 2013) (P < .001), which represents an 84% decrease. This decrease largely occurred between 2006 and 2008, during the Dutch randomized trial on fetal electrocardiogram ST waveform analysis. At this time, approximately 20% of deliveries were monitored using this method. Furthermore, there were significant reductions in fetal blood sampling rate (P < .001). Overall cesarean and vaginal instrumental deliveries decreased significantly (P < .001), but not for fetal distress. There were no changes in the Apgar scores. The incidence of neonatal encephalopathy was significantly lower in the second part of the study (odds ratio 0.39, 95% confidence interval 0.17-0.89).

CONCLUSION

There was an 84% decrease in the incidence of umbilical artery metabolic acidosis in all deliveries between 2000 and 2013. The neonatal encephalopathy rate, fetal blood sampling rate, and the total number of cesarean and vaginal instrumental deliveries also decreased.

Impact of continuous electronic fetal monitoring on birth outcomes in low-risk pregnancies

BACKGROUND

Continuous electronic fetal monitoring (CEFM) is a standard of hospital care during the intrapartum period. We investigated its use on childbirth outcomes in low-risk pregnancies, and examined whether outcomes differed by gestational age within a term pregnancy.

METHODS

A retrospective secondary data analysis using birth registry data from two diverse northeastern US states from 1992 to 2014. Chi-square test and the Fisher exact tests were used to examine associations between CEFM and childbirth outcomes. Multivariable Poisson regression models were used to estimate risk ratios of childbirth outcomes related to CEFM use, adjusting for potential confounders.

RESULTS

Use of CEFM was independently associated with a 10% (State 1) and 40% (State 2) increased risk for primary cesarean delivery and an increased risk for assisted vaginal births (14% and 24%, respectively) after adjustment for confounders. CEFM use was not associated with reduced risk for infant mortality (neonatal mortality, 0-27 days, and post-neonatal mortality, 28-364 days) in term births (37-41 weeks' gestation). After stratifying term pregnancies into early term, full term, and late term, use of CEFM was associated with reduced risk for neonatal mortality in early-term births (37 0/7 weeks' to 38 6/7 weeks' gestation) in State 2 (RR 0.44 [95% CI 0.21-0.92]), but not in State 1. There was no association between CEFM use and infant mortality (neonatal and post-neonatal) in full-term or late-term births.

CONCLUSIONS

The study results do not support universal use of CEFM in pregnancies that are low-risk and at term.

Effectiveness of a Novel Continuous Doppler (Moyo) Versus Intermittent Doppler in Intrapartum Detection of Abnormal Foetal Heart Rate: A Randomised Controlled Study in Tanzania

Background: Intrapartum foetal heart rate (FHR) monitoring is crucial for identification of hypoxic foetuses and subsequent interventions. We compared continuous monitoring using a novel nine-crystal FHR monitor (Moyo) versus intermittent single crystal Doppler (Doppler) for the detection of abnormal FHR. Methods: An unmasked randomised controlled study was conducted in a tertiary hospital in Tanzania (ClinicalTrials.gov Identifier: NCT02790554). A total of 2973 low-risk singleton pregnant women in the first stage of labour admitted with normal FHR were randomised to either Moyo (n = 1479) or Doppler (1494) arms. The primary outcome was the proportion of abnormal FHR detection. Secondary outcomes were time intervals in labour, delivery mode, Apgar scores, and perinatal outcomes. Results: Moyo detected abnormal FHR more often (13.3%) compared to Doppler (9.8%) (p = 0.002). Time intervals from admission to detection of abnormal FHR were 15% shorter in Moyo (p = 0.12) and from the detection of abnormal FHR to delivery was 36% longer in Moyo (p = 0.007) compared to the Doppler arm. Time from last FHR to delivery was 12% shorter with Moyo (p = 0.006) compared to Doppler. Caesarean section rates were higher with the Moyo device compared to Doppler (p = 0.001). Low Apgar scores (<7) at the 1st and 5th min were comparable between groups (p = 0.555 and p = 0.800). Perinatal outcomes (fresh stillbirths and 24-h neonatal deaths) were comparable at delivery (p = 0.497) and 24-h post-delivery (p = 0.345). Conclusions: Abnormal FHR detection rates were higher with Moyo compared to Doppler. Moyo detected abnormal FHR earlier than Doppler, but time from detection to delivery was longer. Studies powered to detect differences in perinatal outcomes with timely responses are recommended.

Intrapartum Fetal Heart Rate: A Possible Predictor of Neonatal Acidemia and APGAR Score

Background: Predicting perinatal outcomes based on patterns of fetal heart rate (FHR) remains a challenge. The aim of this study was to evaluate intrapartum FHR variability as predictor for neonatal acidemia and APGAR score.

Methods: This was a retrospective observational study of 552 childbirths. Multivariable linear regression models were used to assess the association between FHR variability and each of the following outcomes: arterial cord blood pH and base deficit, Apgar 1, and 5 scores. Variables used for adjustment were maternal age, comorbidities (gestational diabetes, preeclampsia, maternal fever, and hypertension), parity, gravidity, uterine contractions, and newborn gestational age, and weight at birth.

Results: The following factors were associated with an increased risk of metabolic acidosis and low Apgar scores at birth: increased mean and coefficient of variation (CV) of the FHR, type of delivery and decreased parity. Each 10-beat/min increase in the FHR was associated with an increase of 0.43 mEq/L in the base deficit, and a decrease of 0.01 in the pH, 0.2 in the Apgar 1, and 0.14 in the Apgar 5 scores. Each 10% increase in the CV of the FHR was associated with an increase of 4.05 mEq/L in the base deficit and a decrease of 0.13 in the pH, 1.31 in the Apgar 1, and 0.86 in the Apgar 5 scores.

Conclusion: These data suggest the intrapartum FHR variability is physiologically relevant and can be used for predicting the acidemia and Apgar scores at birth of the newborn infants without severe cases of morbidity and from uncomplicated pregnancies.

Update on Fetal Monitoring: Overview of Approaches and Management of Category II Tracings

Electronic fetal monitoring (EFM) is widely used to assess fetal status in labor. Use of intrapartum continuous EFM is associated with a lower risk of neonatal seizures but a higher risk of cesarean or operative delivery. Category II fetal heart tracings (FHTs) are indeterminate in their ability to predict fetal acidemia. Certain patterns of decelerations and variability within this category may be predictive of neonatal morbidity. Adjunct tests of fetal well-being can be used during labor to further triage patients. Intrauterine resuscitation techniques should target the suspected etiology of intrapartum fetal hypoxia. Clinical factors play a role in the interpretation of EFM.

The importance of the learning process in ST analysis interpretation and its impact in improving clinical and neonatal outcomes

BACKGROUND

Intrapartum fetal heart rate monitoring was introduced with the goal to reduce fetal hypoxia and deaths. However, continuous fetal heart rate monitoring has been shown to have a high sensitivity but also a high false-positive rate. To improve specificity, adjunctive technologies have been developed to identify fetuses at risk for intrapartum asphyxia. Intensive research on the value of ST-segment analysis of the fetal electrocardiogram as an adjunct to standard electronic fetal monitoring in lowering the rates of fetal metabolic acidosis and operative deliveries has been ongoing. The conflicting results in randomized and observational studies may partly be due to differences in study design.

OBJECTIVE

This study aims to determine the significance of the learning process for the introduction of ST analysis into clinical practice and its impact on initial and subsequent obstetric outcomes.

STUDY DESIGN

This was a prospective observational study with the primary objective to evaluate the importance of the learning period on the rates of metabolic acidosis and operative deliveries after the implementation of ST analysis. The study was conducted at the Turku University Hospital, Turku, Finland, with 3400-4200 annual deliveries. The whole study population consisted of all 42,146 deliveries during the study period 2001 through 2011. The ST analysis usage rate was 18%. The data were collected prospectively from labors monitored with ST analysis as an adjunct to conventional intrapartum fetal heart rate monitoring. Primary endpoints were the rates of metabolic acidosis (cord artery pH <7.05 and an extracellular fluid compartment base deficit >12.0 mmol/L), fetal scalp blood sampling, and operative deliveries. Comparisons of these outcomes were made between the initiation period (the first 2 years) and the subsequent usage period (the next 9 years).

RESULTS

In the whole study population the prevalence of cord pH <7.05 decreased from 1.5-0.81% (relative risk, 0.54; 95% confidence interval, 0.43-0.67), the rate of cesarean deliveries from 17.2-14.1% (relative risk, 0.82; 95% confidence interval, 0.89-0.97), and the rate of fetal scalp blood sampling from 1.75-0.82% (relative risk, 0.47; 95% confidence interval, 0.38-0.58) when the 2 study periods were compared. In the ST analysis group, the frequency of cord metabolic acidosis rate was reduced from 1.0-0.25% (relative risk, 0.33; 95% confidence interval, 0.15-0.72).

CONCLUSION

We provide evidence that the results improve over time and there is a learning curve in the introduction of the ST analysis method. This was demonstrated by the lower rates of metabolic acidosis and operative deliveries after the initial implementation period.

A prospective cohort study of fetal heart rate monitoring: deceleration area is predictive of fetal acidemia

BACKGROUND

Intrapartum electronic fetal monitoring is the most commonly used tool in obstetrics in the United States; however, which electronic fetal monitoring patterns predict acidemia remains unclear.

OBJECTIVE

This study was designed to describe the frequency of patterns seen in labor using modern nomenclature, and to test the hypothesis that visually interpreted patterns are associated with acidemia and morbidities in term infants. We further identified patterns prior to delivery, alone or in combination, predictive of acidemia and neonatal morbidity.

STUDY DESIGN

This was a prospective cohort study of 8580 women from 2010 through 2015. Patients were all consecutive women laboring at ≥37 weeks' gestation with a singleton cephalic fetus. Electronic fetal monitoring patterns during the 120 minutes prior to delivery were interpreted in 10-minute epochs. Interpretation included the category system and individual electronic fetal monitoring patterns per the Eunice Kennedy Shriver National Institute of Child Health and Human Development criteria as well as novel patterns. The primary outcome was fetal acidemia (umbilical artery pH ≤7.10); neonatal morbidities were also assessed. Final regression models for acidemia adjusted for nulliparity, pregestational diabetes, and advanced maternal age. Area under the receiver operating characteristic curves were used to assess the test characteristics of individual models for acidemia and neonatal morbidity.

RESULTS

Of 8580 women, 149 (1.7%) delivered acidemic infants. Composite neonatal morbidity was diagnosed in 757 (8.8%) neonates within the total cohort. Persistent category I, and 10-minute period of category III, were significantly associated with normal pH and acidemia, respectively. Total deceleration area was most discriminative of acidemia (area under the receiver operating characteristic curves, 0.76; 95% confidence interval, 0.72-0.80), and deceleration area with any 10 minutes of tachycardia had the greatest discriminative ability for neonatal morbidity (area under the receiver operating characteristic curves, 0.77; 95% confidence interval, 0.75-0.79). Once the threshold of deceleration area is reached the number of cesareans needed-to-be performed to potentially prevent 1 case of acidemia and morbidity is 5 and 6, respectively.

CONCLUSION

Deceleration area is the most predictive electronic fetal monitoring pattern for acidemia, and combined with tachycardia for significant risk of morbidity, from the electronic fetal monitoring patterns studied. It is important to acknowledge that this study was performed in patients delivering ≥37 weeks, which may limit the generalizability to preterm populations. We also did not use computerized analysis of the electronic fetal monitoring patterns because human visual interpretation was the basis for the Eunice Kennedy Shriver National Institute of Child Health and Human Development categories, and importantly, it is how electronic fetal monitoring is used clinically.

Electronic Fetal Monitoring Documentation: Connecting Points for Quality Care and Communication

Contemporaneous, complete, and objective documentation is the foundation for continuity of patient care and facilitates communication between all levels of healthcare clinicians. The impact of electronic fetal monitoring on obstetric safety has become a high priority, with documentation being essential to evaluating care quality. Over several decades, electronic fetal monitoring documentation has reached a higher level of precision because paper is being replaced with health information technology that incorporates system's features such as checklists, drop-down boxes, and decision analysis. The intent of this article is to provide a synopsis of important concepts regarding electronic fetal monitoring documentation and liability-reduction strategies for perinatal nurses.

Intermittent auscultation versus continuous fetal monitoring: exploring factors that influence birthing unit nurses' fetal surveillance practice using theoretical domains framework

BACKGROUND

Intermittent Auscultation (IA) is the recommended method of fetal surveillance for healthy women in labour. However, the majority of women receive continuous electronic monitoring. We used the Theoretical Domains Framework (TDF) to explore the views of Birthing Unit nurses about using IA as their primary method of fetal surveillance for healthy women in labour.

METHODS

Using a semi-structured interview guide, we interviewed a convenience sample of birthing unit nurses throughout Ontario, Canada to elicit their views about fetal surveillance. Interviews were recorded and transcribed verbatim. Transcripts were content analysed using the TDF and themes were framed as belief statements. Domains potentially key to changing fetal surveillance behaviour and informing intervention design were identified by noting the frequencies of beliefs, content, and their reported influence on the use of IA.

RESULTS

We interviewed 12 birthing unit nurses. Seven of the 12 TDF domains were perceived to be key to changing birthing unit nurses' behaviour The nurses reported that competing tasks, time constraints and the necessity to multitask often limit their ability to perform IA (domains Beliefs about capabilities; Environmental context and resources). Some nurses noted the decision to use IA was something that they consciously thought about with every patient while others stated it their default decision as long as there were no risk factors (Memory, attention and decision processes, Nature of behaviour). They identified positive consequences (e.g. avoid unnecessary interventions, mother-centered care) and negative consequences of using IA (e.g. legal concerns) and reported that the negative consequences can often outweigh positive consequences (Beliefs about consequences). Some reported that hospital policies and varying support from care teams inhibited their use of IA (Social influences), and that support from the entire team and hospital management would likely increase their use (Social influences; Behavioural regulation).

CONCLUSION

We identified potential influences on birthing unit nurses' use of IA as their primary method of fetal surveillance. These beliefs suggest potential targets for behaviour change interventions to promote IA use.

Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour

BACKGROUND

Cardiotocography (CTG) records changes in the fetal heart rate and their temporal relationship to uterine contractions. The aim is to identify babies who may be short of oxygen (hypoxic) to guide additional assessments of fetal wellbeing, or determine if the baby needs to be delivered by caesarean section or instrumental vaginal birth. This is an update of a review previously published in 2013, 2006 and 2001.

OBJECTIVES

To evaluate the effectiveness and safety of continuous cardiotocography when used as a method to monitor fetal wellbeing during labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (30 November 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving a comparison of continuous cardiotocography (with and without fetal blood sampling) with no fetal monitoring, intermittent auscultation intermittent cardiotocography.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, quality and extracted data from included studies. Data were checked for accuracy.

MAIN RESULTS

We included 13 trials involving over 37,000 women. No new studies were included in this update.One trial (4044 women) compared continuous CTG with intermittent CTG, all other trials compared continuous CTG with intermittent auscultation. No data were found comparing no fetal monitoring with continuous CTG. Overall, methodological quality was mixed. All included studies were at high risk of performance bias, unclear or high risk of detection bias, and unclear risk of reporting bias. Only two trials were assessed at high methodological quality.Compared with intermittent auscultation, continuous cardiotocography showed no significant improvement in overall perinatal death rate (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.59 to 1.23, N = 33,513, 11 trials, low quality evidence), but was associated with halving neonatal seizure rates (RR 0.50, 95% CI 0.31 to 0.80, N = 32,386, 9 trials, moderate quality evidence). There was no difference in cerebral palsy rates (RR 1.75, 95% CI 0.84 to 3.63, N = 13,252, 2 trials, low quality evidence). There was an increase in caesarean sections associated with continuous CTG (RR 1.63, 95% CI 1.29 to 2.07, N = 18,861, 11 trials, low quality evidence). Women were also more likely to have instrumental vaginal births (RR 1.15, 95% CI 1.01 to 1.33, N = 18,615, 10 trials, low quality evidence). There was no difference in the incidence of cord blood acidosis (RR 0.92, 95% CI 0.27 to 3.11, N = 2494, 2 trials, very low quality evidence) or use of any pharmacological analgesia (RR 0.98, 95% CI 0.88 to 1.09, N = 1677, 3 trials, low quality evidence).Compared with intermittent CTG, continuous CTG made no difference to caesarean section rates (RR 1.29, 95% CI 0.84 to 1.97, N = 4044, 1 trial) or instrumental births (RR 1.16, 95% CI 0.92 to 1.46, N = 4044, 1 trial). Less cord blood acidosis was observed in women who had intermittent CTG, however, this result could have been due to chance (RR 1.43, 95% CI 0.95 to 2.14, N = 4044, 1 trial).Data for low risk, high risk, preterm pregnancy and high-quality trials subgroups were consistent with overall results. Access to fetal blood sampling did not appear to influence differences in neonatal seizures or other outcomes.Evidence was assessed using GRADE. Most outcomes were graded as low quality evidence (rates of perinatal death, cerebral palsy, caesarean section, instrumental vaginal births, and any pharmacological analgesia), and downgraded for limitations in design, inconsistency and imprecision of results. The remaining outcomes were downgraded to moderate quality (neonatal seizures) and very low quality (cord blood acidosis) due to similar concerns over limitations in design, inconsistency and imprecision.

AUTHORS' CONCLUSIONS

CTG during labour is associated with reduced rates of neonatal seizures, but no clear differences in cerebral palsy, infant mortality or other standard measures of neonatal wellbeing. However, continuous CTG was associated with an increase in caesarean sections and instrumental vaginal births. The challenge is how best to convey these results to women to enable them to make an informed decision without compromising the normality of labour.The question remains as to whether future randomised trials should measure efficacy (the intrinsic value of continuous CTG in trying to prevent adverse neonatal outcomes under optimal clinical conditions) or effectiveness (the effect of this technique in routine clinical practice).Along with the need for further investigations into long-term effects of operative births for women and babies, much remains to be learned about the causation and possible links between antenatal or intrapartum events, neonatal seizures and long-term neurodevelopmental outcomes, whilst considering changes in clinical practice over the intervening years (one-to-one-support during labour, caesarean section rates). The large number of babies randomised to the trials in this review have now reached adulthood and could potentially provide a unique opportunity to clarify if a reduction in neonatal seizures is something inconsequential that should not greatly influence women's and clinicians' choices, or if seizure reduction leads to long-term benefits for babies. Defining meaningful neurological and behavioural outcomes that could be measured in large cohorts of young adults poses huge challenges. However, it is important to collect data from these women and babies while medical records still exist, where possible describe women's mobility and positions during labour and birth, and clarify if these might impact on outcomes. Research should also address the possible contribution of the supine position to adverse outcomes for babies, and assess whether the use of mobility and positions can further reduce the low incidence of neonatal seizures and improve psychological outcomes for women.

Electronic Fetal Monitoring and Cesarean Birth: A Scoping Review

BACKGROUND

In many United States hospitals, electronic fetal monitoring (EFM) is used continuously during labor for all patients regardless of risk status. Application of EFM, particularly at labor admission, may trigger a chain of interventions resulting in increased risk for cesarean birth among low-risk women. The goal of this review was to summarize evidence on use of EFM during low-risk labors and identify gaps in research.

METHODS

We conducted a scoping review of studies published in English since 1996 that addressed the relationship between EFM use and cesarean among low-risk women. We screened 57 full-text articles for appropriateness. Seven articles were included in the final review.

RESULTS

The largest study demonstrated an 81 percent increased risk of primary cesarean birth when EFM was used in labor, but did not differentiate between high- and low-risk pregnancies. Four randomized controlled trials examined the association of admission EFM with obstetric outcomes; only one considered cesarean birth as a primary outcome and found a 23 percent increase in operative birth when EFM lasted more than 1 hour. A study examining application of continuous EFM before and after 4 centimeters dilatation found no differences between groups.

CONCLUSIONS

In general, the research on this topic suggests an association between the use of EFM and cesarean birth; however, more well-designed studies are needed to examine benefits of EFM versus auscultation, determine if EFM is associated with use of other technologies that could cumulatively increase risk of cesarean birth, and understand provider motivation to use EFM over auscultation.

Cardiotocography in breech versus vertex delivery: an examiner-blinded, cross-sectional nested case-control study

BACKGROUND

The safety of vaginal breech delivery has been debated for decades. Although it has been shown to predispose infants to immediate depression, several observational studies have also shown that attempting vaginal breech delivery does not increase perinatal morbidity or low Apgar score at the age of five minutes. Cardiotocography monitoring is recommended during vaginal breech delivery, but comparative data describing differences between cardiotocography tracings in breech and vertex deliveries is scarce. This study aims to evaluate differences in intrapartum cardiotocography tracings between breech and vertex deliveries in the final 60 min of delivery. A secondary goal is to identify risk factors for suboptimal neonatal outcome in the study population.

METHODS

One hundred eight breech and 108 vertex singleton, intended vaginal deliveries at term from a tertiary hospital with 5000 annual deliveries were included. Two experienced obstetricians, blinded to fetal presentation, neonatal outcome and actual mode of delivery, evaluated traces recorded 60 min before delivery. They provided a three-tier classification and evaluated different trace features according to FIGO (1987) guidelines. Factors associated with acidemia and low Apgar scores were identified by univariate and multivariable analyses performed with binary logistic regression. Student's T-test and chi-square test were used, as appropriate.

RESULTS

Late decelerations were seen in 13.9 % of breech and 2.8 % of vertex deliveries (p = 0.003) and decreased variability in 26.9 % of breech and 8.3 % of vertex deliveries (p < 0.001). In multivariable analysis complicated variable decelerations and breech presentation were identified as risk factors for neonatal acidemia and low Apgar score at the age of five minutes. Pathological trace and breech presentation were independent risk factors for low Apgar score at the age of one minute.

CONCLUSIONS

Decreased variability and late decelerations were more prevalent in breech compared to vertex deliveries. Pathological trace predicts immediate neonatal depression and especially complicated variable decelerations may signal more severe distress. Further research is needed to create guidelines for safe management of vaginal breech delivery.

Gestational diabetes in the United States: temporal changes in prevalence rates between 1979 and 2010

OBJECTIVE

To examine age-period-cohort effects on trends in gestational diabetes mellitus (GDM) prevalence in the US, and to evaluate how these trends have affected the rates of stillbirth and large for gestational age (LGA)/macrosomia.

DESIGN

Retrospective cohort study.

SETTING

USA, 1979-2010.

POPULATION

Over 125 million pregnancies (3 337 284 GDM cases) associated with hospitalisations.

METHODS

Trends in GDM prevalence were examined via weighted Poisson models to parse out the extent to which GDM trends can be attributed to maternal age, period of delivery, and maternal birth cohort. Multilevel models were used to assess the contribution of population effects to the rate of GDM. Log-linear Poisson regression models were used to estimate the contributions of the increasing GDM rates to changes in the rates of LGA and stillbirth between 1979-81 and 2008-10.

MAIN OUTCOME MEASURES

Rates and rate ratios (RRs).

RESULTS

Compared with 1979-1980 (0.3%), the rate of GDM has increased to 5.8% in 2008-10, indicating a strong period effect. Substantial age and modest cohort effects were evident. The period effect is partly explained by period trends in body mass index (BMI), race, and maternal smoking. The increasing prevalence of GDM is associated with a 184% (95% CI 180-188%) decline in the rate of LGA/macrosomia and a 0.75% (95% CI 0.74-0.76) increase in the rate of stillbirths for 2008-10, compared with 1979-81.

CONCLUSIONS

The temporal increase in GDM can be attributed to period of pregnancy and age. Increasing BMI appears to partially contribute to the GDM increase in the US.

TWEETABLE ABSTRACT

The increasing prevalence of GDM can be attributed to period of delivery and increasing maternal age.

Birth Outcomes, Intervention Frequency, and the Disappearing Midwife-Potential Hazards of Central Fetal Monitoring: A Single Center Review

INTRODUCTION

Many birth units use central fetal monitoring (CFM) under the assumption that greater surveillance improves perinatal outcomes. The unexpected loss of the CFM system at a tertiary unit provided a unique opportunity to evaluate outcomes and staff attitudes toward CFM.

METHODS

This retrospective cohort study compared patient data from 2,855 electronically monitored women delivering over a 12-month period, where CFM was available for the first 6 months but unavailable for the following 6 months. Primary outcomes relating to neonatal morbidity and secondary outcomes relating to intrapartum interventions were examined. Additionally, birth unit staff members were surveyed about aspects of care related to CFM.

RESULTS

There were no significant differences in perinatal outcomes between the cohorts. While unadjusted analysis suggested a lower spontaneous vaginal birth rate (55.4% vs 60.3%) and a higher cesarean delivery rate (25.1% vs 22.0%, p = 0.026), together with higher epidural (53.0% vs 49.2%, p = 0.04) and fetal blood sampling (11.8% vs 9.4%, p = 0.03) rates in the presence of CFM, these differences were lost when adjusted for prostaglandin ripening. Over half of the staff (56.0% of midwives, 54.0% of obstetricians) reported spending more time with the laboring woman in the period without CFM.

CONCLUSIONS

This single institution's experience indicates that in birth units staffed for one-to-one care in labor, central fetal monitoring does not appear to be associated with either a benefit on perinatal outcomes or an increase in cesarean delivery and other interventions. However, it is associated with a reduction in the time a midwife spends with the laboring woman.

The Effect of Adequate Gestational Weight Gain among Adolescents Relative to Adults of Equivalent Body Mass Index and the Risk of Preterm Birth, Cesarean Delivery, and Low Birth Weight

OBJECTIVE

To determine whether similar odds of cesarean delivery (C/S), preterm birth (PTB), and low birth weight (LBW) are observed among adolescents compared with body mass index (BMI)-equivalent adults in cases of adequate gestational weight gain.

STUDY DESIGN

We conducted a retrospective, population-based, cohort study using the Center for Disease Control and Prevention's birth data files from the United States for 2012. We selected from the cohort all singleton, cephalic pregnancies and stratified them according to maternal age, prepregnancy BMI, and gestational weight gain following the 2009 Institute of Medicine (IOM) recommendations. The effect of adequate gestational weight gain among adolescents relative to adults of equivalent BMI on the risk of C/S, PTB, and LBW was estimated using logistic regression analysis, adjusting for relevant confounders.

RESULTS

We analyzed a total of 3,960,796 births, of which 1,036,646 (26.1%) met the inclusion criteria. In adolescents and adults, likelihood of achieving ideal gestational weight gain decreased with greater prepregnancy BMI. Relative to adults, the overall odds of C/S in all adolescents were (adjusted odds ratio [95% confidence interval]) 0.61 (0.58 to 0.63). When comparing equivalent BMI categories, these odds were unchanged (P < .0001). The overall adjusted odds ratio of LBW was 1.15 (1.13 to 1.16). These odds were significantly higher when BMI stratification took place, decreasing with advancing BMI categories, from 1.23 (1.14 to 1.33) among the underweight, to nonsignificant differences in the obese classes (P < .05). Finally, when including only those achieving ideal weight gain, the overall odds of premature delivery (1.17 [1.14 to 1.20]) were higher among nonobese adolescents, while they were not found among the obese.

CONCLUSION

When ideal gestational weight gain is attained, only nonobese adolescents exhibit a greater risk of LBW and preterm birth relative to adults of similar BMI, whereas the risk of C/S remains lower for all adolescents, independent of BMI. This information may be useful in the counseling of adolescent pregnancies.

A three class treatment of the FHR classification problem using latent class analysis labeling

Electronic Fetal Monitoring in the form of cardiotocography is routinely used for fetal assessment both during pregnancy and delivery. However its interpretation requires a high level of expertise and even then the assessment is somewhat subjective as it has been proven by the high inter and intra-observer variability. Therefore the scientific community seeks for more objective methods for its interpretation. Along this path, presented work proposes a classification approach, which is based on a latent class analysis method that attempts to produce more objective labeling of the training cases, a step which is vital in a classification problem. The method is combined with a simple logistic regression approach under two different schemes: a standard multi-class classification formulation and an ordinal classification one. The results are promising suggesting that more effort should be put in this proposed approach.

[Electronic fetal monitoring and its relationship to neonatal and infant mortality in a national database: A sensitivity analysis]

OBJECTIVE

Sensitivity analysis of the association between electronic fetal monitoring and neonatal and infant mortality previously reported from a United States database.

MATERIALS AND METHODS

Retrospective cohort study of 11,916,806 live births linked to neonatal and infant deaths during the years 1997-2002 from the United States Centers for Disease Control's National Center of Health Statistics (NCHS) linked birth and infant death data. Restrictions were performed to exclude deliveries occurring outside of a hospital, precipitous labors, breech deliveries, eleven risk factors of pregnancy, multiple gestations, deliveries before 24 and after 44 weeks, implausible birthweights, repeat cesarean sections, and congenital anomalies. An additional analysis explored the effect of further restrictions to term births, birth weight≥2500 g, absence of maternal fever (>38°C), and absence of labor induction or augmentation. For each year, adjusted relative risks (RR) were estimated with log binomial regression. A six-year pooled association was estimated by the generic inverse variance method using a random effects model.

RESULTS

For the six-year period, there was a significant reduction in risk in the group with electronic fetal monitoring for early neonatal mortality (RR=0.54, 95 % CI: 0.52-0.57), late neonatal mortality (RR=0.84, 95 % CI: 0.78-0.90), post-neonatal mortality (RR=0.86, 95 % CI: 0.83-0.90), and infant mortality from all causes (RR=0.75, 95 % CI: 0.73-0.77), from perinatal causes (RR=0.60, 95 % CI: 0.57-0.63), and from hypoxia (RR=0.67, 95 % CI: 0.54-0.84). In the additional analysis, which only examined the outcome of infant mortality from all causes, there was also a significant reduction in risk (RR=0.91, 95 % CI: 0.85-0.97).

CONCLUSION

Using the NCHS linked birth and infant death data over a 6-year period, electronic fetal monitoring was associated with decreased neonatal and infant mortality as has been previously reported. These results were robust to two levels of restriction applied on potential confounding variables.

Institutional and Cultural Perspectives on Home Birth in Israel

This study exposes doctors' and midwives' perceptions and misperceptions regarding home birth by examining their views on childbirth in general and on risk associated with home births in particular. It relies on an approach of risk communication and an anthropological framework. In a qualitative-constructive study, 19 in-depth interviews were conducted with hospital doctors, hospital midwives, home-birth midwives, and a home-birth obstetrician. Our findings reveal that hospital midwives and doctors suffer from lack of exposure to home births, leading to disagreement regarding norms and risk; it also revealed sexist or patriarchal worldviews. Recommendations include improving communication between home-birth midwives and hospital counterparts; increased exposure of hospital doctors to home birth, creating new protocols in collaboration with home-birth midwives; and establishing a national database of home births.

Correlating multidimensional fetal heart rate variability analysis with acid-base balance at birth

Fetal monitoring during labour currently fails to accurately detect acidemia. We developed a method to assess the multidimensional properties of fetal heart rate variability (fHRV) from trans-abdominal fetal electrocardiogram (fECG) during labour. We aimed to assess this novel bioinformatics approach for correlation between fHRV and neonatal pH or base excess (BE) at birth.We enrolled a prospective pilot cohort of uncomplicated singleton pregnancies at 38-42 weeks' gestation in Milan, Italy, and Liverpool, UK. Fetal monitoring was performed by standard cardiotocography. Simultaneously, with fECG (high sampling frequency) was recorded. To ensure clinician blinding, fECG information was not displayed. Data from the last 60 min preceding onset of second-stage labour were analyzed using clinically validated continuous individualized multiorgan variability analysis (CIMVA) software in 5 min overlapping windows. CIMVA allows simultaneous calculation of 101 fHRV measures across five fHRV signal analysis domains. We validated our mathematical prediction model internally with 80:20 cross-validation split, comparing results to cord pH and BE at birth.The cohort consisted of 60 women with neonatal pH values at birth ranging from 7.44 to 6.99 and BE from -0.3 to -18.7 mmol L(-1). Our model predicted pH from 30 fHRV measures (R(2) = 0.90, P < 0.001) and BE from 21 fHRV measures (R(2) = 0.77, P < 0.001).Novel bioinformatics approach (CIMVA) applied to fHRV derived from trans-abdominal fECG during labor correlated well with acid-base balance at birth. Further refinement and validation in larger cohorts are needed. These new measurements of fHRV might offer a new opportunity to predict fetal acid-base balance at birth.

Changes in the cesarean section rate in Korea (1982-2012) and a review of the associated factors

Although Cesarean section (CS) itself has contributed to the reduction in maternal and perinatal mortality, an undue rise in the CS rate (CSR) has been issued in Korea as well as globally. The CSR in Korea increased over the past two decades, but has remained at approximately 36% since 2006. Contributing factors associated with the CSR in Korea were an improvement in socio-economic status, a higher maternal age, a rise in multiple pregnancies, and maternal obesity. We found that countries with a no-fault compensation system maintained a lower CSR compared to that in countries with civil action, indicating the close relationship between the CSR and the medico-legal system within a country. The Korean government has implemented strategies including an incentive system relating to the CSR or encouraging vaginal birth after Cesarean to decrease CSR, but such strategies have proved ineffective. To optimize the CSR in Korea, efforts on lowering the maternal childbearing age or reducing maternal obesity are needed at individual level. And from a national view point, reforming health care system, which could encourage the experienced obstetricians to be trained properly and be relieved from legal pressure with deliveries is necessary.

Diagnostic accuracy of fetal heart rate monitoring in the identification of neonatal encephalopathy

OBJECTIVE

To estimate the diagnostic accuracy of electronic fetal heart rate abnormalities in the identification of neonates with encephalopathy treated with whole-body hypothermia.

METHODS

Between January 1, 2007, and July 1, 2013, there were 39 neonates born at two hospitals within our system treated with whole-body hypothermia within 6 hours of birth. Neurologically normal control neonates were matched to each case by gestational age and mode of delivery in a two-to-one fashion. The last hour of electronic fetal heart rate monitoring before delivery was evaluated by three obstetricians blinded to outcome.

RESULTS

The differences in tracing category were not significantly different (neonates in the case group 10.3% I, 76.9% II, 12.8% III; neonates in the control group 9.0% I, 89.7% II, 1.3% III; P=.18). Bivariate analysis showed neonates in the case group had significantly increased late decelerations, total deceleration area 30 (debt 30) and 60 minutes (debt 60) before delivery and were more likely to be nonreactive. Multivariable logistic regression showed neonates in the case group had a significant decrease in early decelerations (P=.03) and a significant increase in debt 30 (.01) and debt 60 (P=.005). The area under the receiver operating characteristic curve, sensitivity, and specificity were 0.72, 23.1%, and 94.9% for early decelerations; 0.66, 33.3%, and 87.2% for debt 30, and 0.68, 35.9%, and 89.7% for debt 60, respectively.

CONCLUSION

Abnormalities during the last hour of fetal heart rate monitoring before delivery are poorly predictive of neonatal hypoxic-ischemic encephalopathy qualifying for whole-body hypothermia treatment within 6 hours of birth. LEVEL OF EVIEDENCE: II.

New estimators and guidelines for better use of fetal heart rate estimators with Doppler ultrasound devices

Characterizing fetal wellbeing with a Doppler ultrasound device requires computation of a score based on fetal parameters. In order to analyze the parameters derived from the fetal heart rate correctly, an accuracy of 0.25 beats per minute is needed. Simultaneously with the lowest false negative rate and the highest sensitivity, we investigated whether various Doppler techniques ensure this accuracy. We found that the accuracy was ensured if directional Doppler signals and autocorrelation estimation were used. Our best estimator provided sensitivity of 95.5%, corresponding to an improvement of 14% compared to the standard estimator.