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.

Comparison of the incidence of fetal prolonged deceleration after induction of labor analgesia between dural puncture epidural and combined spinal epidural technique: a pilot study.

BACKGROUND: Abnormal cardiotocogram (CTG) tracing may appear after induction of neuraxial labor analgesia. Non-reassuring fetal status (NRFS) indicated by severely abnormal tracings, such as prolonged deceleration (PD) or bradycardia, can necessitate immediate operative delivery. Combined spinal epidural analgesia (CSEA) is known to result in more frequent abnormal tracings than epidural analgesia (EA); however, the corresponding data related to dural puncture epidural (DPE) are unclear. We aimed to evaluate the rates of incidence of severe abnormal CTG after induction of DPE and CSEA. METHODS: In this study of nulliparous women with full-term pregnancy, data for the DPE intervention group were prospectively collected, while those for the CSEA control group were obtained from medical records. Neuraxial analgesia was performed with cervical dilation ≤ 5 cm, administering initial epidural dosing of 15 mL of 0.125% levobupivacaine with fentanyl 2.5µg/mL for DPE, and intrathecal 0.5% bupivacaine 2.5 mg (0.5ml), fentanyl 10 µg (0.2ml), and 1.3 mL of saline for CSEA. The primary outcome was the incidence of PD, defined as a fetal heart rate reduction ≥ 15 bpm below the baseline and with a lowest value < 80 bpm, and lasting for ≥ 2 min but < 10 min (fetal heart rate < 80 bpm does not have to last for ≥ 2 min), within 90 min after induction of neuraxial labor analgesia. RESULTS: A total of 302 patients were analyzed, with 151 in each group. The incidence of PD after DPE induction was significantly lower than that after CSEA induction (4.0% vs. 14.6%, P = 0.0015, odds ratio = 0.243, 95% confidence interval = 0.095-0.617). CONCLUSION: DPE appears to be a safer method compared to CSEA for neuraxial labor analgesia in the early stages of labor for nulliparous women. TRIAL REGISTRATION: UMIN-CTR: UMIN000035153 . Date registered: 01/01/2019.

Feasibility of a mobile cardiotocogram device for fetal heart rate self-monitoring in low-risk singleton pregnant women.

AIM: This study aimed to clarify the feasibility of a mobile cardiotocogram (CTG) device for self-monitoring fetal heart rate (FHR) in low-risk singleton pregnant women. METHODS: This study was conducted at six university hospitals and seven maternity clinics in Japan. Using a mobile cardiotocogram device (iCTG, Melody International Ltd., Kagawa, Japan), participants of more than 34 gestational weeks measured the FHR by themselves at least once a week until hospitalization for delivery. We evaluated the acquisition rate of evaluable FHR recordings and the frequency of abnormal FHR patterns according to the CTG classification system of the Japan Society of Obstetrics and Gynecology (JSOG). The participants also underwent a questionnaire survey after delivery to evaluate their satisfaction level of self-monitoring FHR using the mobile CTG device. RESULTS: A total of 1278 FHR recordings from 101 women were analyzed. Among them, 1276 (99.8%) were readable for more than 10 min continuously, and the median percentage of the total readable period in each recording was 98.9% (range, 51.4-100). According to the JSOG classification system, 1245 (97.6%), 9 (0.7%), 18 (1.4%), and four (0.3%) FHR patterns were classified as levels 1, 2, 3, and 4, respectively. The questionnaire survey revealed high participant satisfaction with FHR self-monitoring using the iCTG. CONCLUSION: The mobile CTG device is a feasible tool for self-monitoring FHR, with a high participant satisfaction level.

Non-invasive fetal electrocardiography, electrohysterography and speckle-tracking echocardiography in the second trimester: study protocol of a longitudinal prospective cohort study (BEATS-study).

BACKGROUND: Worldwide, hypertensive disorders of pregnancy (HDP), fetal growth restriction (FGR) and preterm birth remain the leading causes of maternal and fetal pregnancy-related mortality and (long-term) morbidity. Fetal cardiac deformation changes can be the first sign of placental dysfunction, which is associated with HDP, FGR and preterm birth. In addition, preterm birth is likely associated with changes in electrical activity across the uterine muscle. Therefore, fetal cardiac function and uterine activity can be used for the early detection of these complications in pregnancy. Fetal cardiac function and uterine activity can be assessed by two-dimensional speckle-tracking echocardiography (2D-STE), non-invasive fetal electrocardiography (NI-fECG), and electrohysterography (EHG). This study aims to generate reference values for 2D-STE, NI-fECG and EHG parameters during the second trimester of pregnancy and to investigate the diagnostic potential of these parameters in the early detection of HDP, FGR and preterm birth. METHODS: In this longitudinal prospective cohort study, eligible women will be recruited from a tertiary care hospital and a primary midwifery practice. In total, 594 initially healthy pregnant women with an uncomplicated singleton pregnancy will be included. Recordings of NI-fECG and EHG will be made weekly from 22 until 28 weeks of gestation and 2D-STE measurements will be performed 4-weekly at 16, 20, 24 and 28 weeks gestational age. Retrospectively, pregnancies complicated with pregnancy-related diseases will be excluded from the cohort. Reference values for 2D-STE, NI-fECG and EHG parameters will be assessed in uncomplicated pregnancies. After, 2D-STE, NI-fCG and EHG parameters measured during gestation in complicated pregnancies will be compared with these reference values. DISCUSSION: This will be the a large prospective study investigating new technologies that could potentially have a high impact on antepartum fetal monitoring. TRIAL REGISTRATION: Registered on 26 March 2020 in the Dutch Trial Register (NL8769) via https://www.trialregister.nl/trials and registered on 21 October 2020 to the Central Committee on Research Involving Human Subjects (NL73607.015.20) via https://www.toetsingonline.nl/to/ccmo_search.nsf/Searchform?OpenForm .

Accuracy of predicting neonatal distress using a five-level classification of fetal heart rate monitoring.

AIM: To assess the accuracy of neonatal distress prediction using the five-level classification of fetal heart rate (FHR) and management protocol of the Japan Society of Obstetrics and Gynecology (JSOG). METHODS: A case-control study was conducted. Vertex singleton pregnant women who delivered after 37 weeks' gestation from 2013 to 2015 were enrolled. The participants were categorized into two groups; controls were levels 1-3 (n = 1184), whereas cases were levels 4-5 (n = 117) group. Neonatal distress was defined as Apgar score < 8 points at 5 min or umbilical cord artery pH < 7.1. RESULTS: There were 117 cases (9.0%). The frequency of the neonatal distress was observed in 1.3% controls and 6.8% cases (P < 0.01). Diagnostic accuracy of neonatal distress for cases showed a 6.8% positive-predictive value, 34.8% sensitivity, 91.5% specificity and 98.7% negative-predictive value. Among various obstetrical conditions, high sensitivity (100%) for prediction of neonatal distress was observed in women with chromosome abnormalities, placental abruption, umbilical cord abnormalities and excessive labor pain. Conversely, relatively low specificity (<50%) was observed in cases with oligohydramnios and excessive labor pain. CONCLUSION: The five-level classification scheme was efficient for neonatal distress prediction. However, depending on the obstetric condition, the FHR findings and neonatal condition might be independent.

Measuring the impact of cardiotocograph decision support software on neonatal outcomes: A propensity score-matched observational study.

BACKGROUND: This study follows the 2017 UK INFANT Collaborative Group RCT, which compared neonatal outcomes with and without the use of the INFANT cardiotocograph decision support system for over 46 000 patients in labour. The original trial failed to demonstrate a significant improvement to neonatal outcomes; however, the study design was subject to methodological critique. AIMS: This Australian retrospective cohort study aimed to report perinatal outcomes before and after the introduction of INFANT decision support software for cardiotocograph use in labour. MATERIALS AND METHODS: The study cohort was divided into two equivalent 18-month epochs, before and after the introduction of INFANT-Guardian® CTG decision support system. Propensity score matching analysis was undertaken to balance pre- and post-implementation groups by baseline covariates. The matched cohort included 11 154 public-funded women between November 2016 and 2019, with a singleton live fetus ≥34 + 0 weeks, being induced or in spontaneous labour. The main outcome measures were: a composite measure of serious adverse neonatal outcome comprising of one or more of: admission to intensive care nursery >48 h, Apgar <4 at 5 min, cord arterial pH <7.0, hypoxic ischaemic encephalopathy grade 2 or 3, therapeutic hypothermia, neonatal death. RESULTS: The incidence of the composite primary outcome was significantly lower following implementation of INFANT (0.57% vs. 1.00%; OR 0.57, 95%CI 0.37-0.88; P = 0.01). A significant reduction in nursery admission >48 h was also observed (0.05% vs. 0.30%; OR 0.18, 95%CI 0.05-0.60; P = 0.002). CONCLUSIONS: INFANT software is associated with a reduction in serious adverse neonatal outcomes, without increasing the rate of operative delivery.

Prediction of Hypoxic Acidemia in Last 2 Hours of Labour in Low-Risk Women.

OBJECTIVE: Prediction of hypoxic acidemia in neonates using cardiotocogram (CTG) features continues to be challenging. The objective of this study was to explore the association between contraction frequency and fetal heart rate characteristics with hypoxic acidemia in low-risk women in labour. METHODS: Cases were singleton, vertex, in labour with umbilical artery pH ≤7.05. Controls were the next consecutive birth with pH ≥7.15, matched for gestational age, maternal age, and parity. Obstetrical complications and maternal comorbidities were excluded. CTG features were tabulated for the last 2 hours of labour. "Cut-off points" above which acidemia is more likely were calculated for significant variables (Canadian Task Force Classification II-2). RESULTS: A total of 190 case-control pairs were included. Among cases we observed greater marked variability, tachycardia, variable and late decelerations, and fewer accelerations and early decelerations. A conditional logistic regression model included tachycardia, accelerations, total decelerations, and contractions. Tachycardia and total decelerations (variable, late) were significant. Tachycardia was most specific in predicting neonatal acidemia, whereas total (variable, late) decelerations were most sensitive. Late decelerations alone and total (variable, late) decelerations were similarly predictive for detecting neonatal acidemia using receiver-operating characteristic analysis; tachycardia was least discriminatory. Acidemic neonates were more likely to have CTGs with ≥11 late decelerations, ≥15 total decelerations (variable, late), and at least 80 minutes of tachycardia in the last 2 hours of labour. CONCLUSION: Tachycardia, late decelerations, and total (variable, late) decelerations were associated with acidosis in our population. Identifying "cut-off" points for the frequency of significant CTG features should be explored as a potential screening tool for neonatal acidemia.

Simplifying the language of fetal monitoring.

BACKGROUND: Health professionals in Australia and New Zealand have used various intrapartum fetal surveillance (IFS) guidelines, with clear differences in how these guidelines present information. Based on clinician feedback, the 2015 Queensland Clinical Guideline on IFS structured the prose-based Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) IFS Guidelines as a traffic-light matrix and represented the categorical terms of unlikely, maybe, possible and likely fetal compromise, as the colours GREEN, BLUE, AMBER, and RED, respectively. AIMS: To determine whether the interpretation of the RANZCOG IFS Guidelines in Table Format is more accurate and quicker compared to the current presentation of the RANZCOG Guideline in prose format. MATERIALS AND METHOD: Twenty-nine clinicians, naïve to the use of the RANZCOG IFS Guidelines, interpreted ten cardiotocographs (CTGs) using one format and then the alternative format (totalling 580 CTG interpretations). Accuracy and time to decision were recorded as well as a participant questionnaire. A repeated measures analysis of variance was used to compare differences. RESULTS: Compared to prose format, clinicians interpreted CTGs quicker using the table format (P < 0.01), especially CTGs representative of unlikely and maybe fetal compromise. There was a trend toward more accurate interpretation for table format for all clinicians, with significance among medical officers (P = 0.02). Participants responded more favourably to the table format regarding questions about ease of use, determining actions required, and desire to use the system in the future (P < 0.01). CONCLUSIONS: Presenting the RANZCOG IFS Guideline in table format as opposed to prose format improved the speed and accuracy of CTG interpretation and is preferred by clinicians.

Results from the National Perinatal Patient Safety Program in Sweden: the challenge of evaluation.

INTRODUCTION: We studied the effects of the national Perinatal Patient Safety Program in Sweden, addressing local improvement measures, changes in the proportion of low Apgar score and the number of settled injury claims due to asphyxia. MATERIAL AND METHODS: Final reports on achieved improvements from all Swedish obstetric units were analyzed and categories of the improvement measures taken in perinatal risk areas were established. Data on all term newborns during 2006-12 were obtained from the Medical Birth Registry. Incidence of 5-min Apgar score <7 was analyzed before, during and after the intervention. The odds ratio for low Apgar score in period ÍII vs. period I was calculated. Patient injury claims from The Swedish National Patient Insurance Company (LÖF) were analyzed. RESULTS: Numerous local improvement initiatives were reported. The incidence of 5-min Apgar score <7 on a national level remained unchanged during the study periods. The units with the highest rate of Apgar score <7 showed a significant decrease in Apgar score of 4-6 after the intervention, whereas units with the lowest rate of Apgar score <7 showed a significant increase in Apgar score <7 after the intervention. A decline in settled claims due to substandard care was observed (7.5%, 2012-14; p for trend 0.049). CONCLUSION: The national incidence of low Apgar score remained unchanged but a reduction of settled claims of severely asphyxiated neonates was observed. The study highlights the need for robust designs when evaluating large-scale initiatives for improving patient safety at delivery, along with the difficulties in performing them.

Decreased baseline variability on fetal heart rate pattern in a fetus with heterotaxy syndrome.

In a fetus with suspected heterotaxy syndrome, a decreased/absent baseline variability of fetal heart rate pattern developed at gestational week 36(+5) and continued for 5 days until birth at gestational week 37(+2), while repeat biophysical profile scorings with ultrasound were consistently unremarkable. This neonate weighing 2404 g with Apgar scores of 7 (1-min) and 8 (5-min) and umbilical arterial cord blood pH of 7.28 with base deficit of 3.9 mmol/L, showed a heart rate of 120 b.p.m. for 3 h after birth, but subsequently developed sinus bradycardia (84 b.p.m.) unresponsive to crying. Isoproterenol initiated 9 h after birth was effective in the increase of heart rate to 120 b.p.m. in this neonate. Brain magnetic resonance imaging at 16 days of age was unremarkable. The decreased/absent baseline variability of fetal heart rate pattern was speculated to have been caused by sinus node dysfunction, and not by reduced fetal oxygenation in this case.

Artificial intelligence based cardiotocogram assessment during labor.

OBJECTIVE: To assess whether artificial intelligence, inspired by clinical decision-making procedures in delivery rooms, can correctly interpret cardiotocographic tracings and distinguish between normal and pathological events. STUDY DESIGN: A method based on artificial intelligence was developed to determine whether a cardiotocogram shows a normal response of the fetal heart rate to uterine activity (UA). For a given fetus and given the UA and previous FHR, the method predicts a fetal heart rate response, under the assumption that the fetus is still in good condition and based on how that specific fetus has responded so far. We hypothesize that this method, when having only learned from fetuses born in good condition, is incapable of predicting the response of a compromised fetus or an episode of transient fetal distress. The (in)capability of the method to predict the fetal heart rate response would then yield a method that can help to assess fetal condition when the obstetrician is in doubt. Cardiotocographic data of 678 deliveries during labor were selected based on a healthy outcome just after birth. The method was trained on the cardiotocographic data of 548 fetuses of this group to learn their heart rate response. Subsequently it was evaluated on 87 fetuses, by assessing whether the method was able to predict their heart rate responses. The remaining 43 cardiotocograms were segment-by-segment annotated by three experienced gynecologists, indicating normal, suspicious, and pathological segments, while having access to the full recording and neonatal outcome. This future knowledge makes the expert annotations of a quality that is unachievable during live interpretation. RESULTS: The comparison between abnormalities detected by the method (only using past and present input) and the annotated CTG segments by gynecologists (also looking at future input) yields an area under the curve of 0.96 for the distinction between normal and pathological events in majority-voted annotations. CONCLUSION: The developed method can distinguish between normal and pathological events in near real-time, with a performance close to the agreement between three gynecologists with access to the entire CTG tracing and fetal outcome. The method has a strong potential to support clinicians in assessing fetal condition in clinical practice.

Prediction of intrapartum fetal compromise at the end of pregnancy; is Doppler, and not weight, that matters.

Despite the fact that labor depends on too many interacting factors and no parameter can fully predict its outcome, fetal cerebral Doppler has emerged as the most reliable tool for prediction, in contrast with fetal weight, which performs significantly worse in the last weeks of pregnancy. The importance of the cerebral Doppler follows the inverse pathway of fetal weight increasing its performance in the last weeks of pregnancy and reaching its highest ability prior to labor. A combination of cerebral flow, fetal weight, and selected clinical information may obtain moderate predictions of labor outcome, provided the interval to labor is not long.

Acute fetal asphyxia after gastric rupture in a pregnant patient with a gastric band.

We report a 37-year-old primigravida with a gastric band who developed the clinical picture of abdominal pain, vomiting and regurgitation coexistent with a cardiotocogram with severe variable decelerations with absent variability at 33 weeks' gestation. After partial improvement with gastric band enlargement, new aggravation of symptoms and recurrence of a pathological cardiotocogram led to an emergency cesarean section. Intraoperatively, hemoperitoneum from gastric rupture was verified and partial gastrectomy was performed. After bariatric surgery, pregnant women are at increased risk of gastrointestinal complications, which may need prompt and multidisciplinary diagnosis and management in order to avoid maternal-fetal morbidity and mortality.

Use of Deep Learning to Detect the Maternal Heart Rate and False Signals on Fetal Heart Rate Recordings.

We have developed deep learning models for automatic identification of the maternal heart rate (MHR) and, more generally, false signals (FSs) on fetal heart rate (FHR) recordings. The models can be used to preprocess FHR data prior to automated analysis or as a clinical alert system to assist the practitioner. Three models were developed and used to detect (i) FSs on the MHR channel (the FSMHR model), (ii) the MHR and FSs on the Doppler FHR sensor (the FSDop model), and (iii) FSs on the scalp ECG channel (the FSScalp model). The FSDop model was the most useful because FSs are far more frequent on the Doppler FHR channel. All three models were based on a multilayer, symmetric, GRU, and were trained on data recorded during the first and second stages of delivery. The FSMHR and FSDop models were also trained on antepartum recordings. The training dataset contained 1030 expert-annotated periods (mean duration: 36 min) from 635 recordings. In an initial evaluation of routine clinical practice, 30 fully annotated recordings for each sensor type (mean duration: 5 h for MHR and Doppler sensors, and 3 h for the scalp ECG sensor) were analyzed. The sensitivity, positive predictive value (PPV) and accuracy were respectively 62.20%, 87.1% and 99.90% for the FSMHR model, 93.1%, 95.6% and 99.68% for the FSDop model, and 44.6%, 87.2% and 99.93% for the FSScalp model. We built a second test dataset with a more solid ground truth by selecting 45 periods (lasting 20 min, on average) on which the Doppler FHR and scalp ECG signals were recorded simultaneously. Using scalp ECG data, the experts estimated the true FHR value more reliably and thus annotated the Doppler FHR channel more precisely. The models achieved a sensitivity of 53.3%, a PPV of 62.4%, and an accuracy of 97.29%. In comparison, two experts (blinded to the scalp ECG data) respectively achieved a sensitivity of 15.7%, a PPV of 74.3%, and an accuracy of 96.91% and a sensitivity of 60.7%, a PPV of 83.5% and an accuracy of 98.24%. Hence, the models performed at expert level (better than one expert and worse than the other), although a well-trained expert with good knowledge of FSs could probably do better in some cases. The models and datasets have been included in the Fetal Heart Rate Morphological Analysis open-source MATLAB toolbox and can be used freely for research purposes.

Intrapartum cardiotocogram monitoring between obstetricians and computer analysis.

Purpose: To investigate the accuracy of computer analysis and its features to be used as a fu fetal heart rate (FHR) interpretation method in clinical settings.Methods: The Trium CTG Online® was used as the computer analysis software. Twenty-six cases of intrapartum FHR tracings (total time, 6900 min) were randomly selected from third-trimester pregnancies. Three obstetricians blinded to the patients' clinical information traced the decelerations, variability, and baseline cardiotocogram (CTG) data. Three obstetrician observer individually interpreted the data and only the waveforms they interpreted were adopted. The agreement between the deceleration and baseline, variability, and level of five-tier system was estimated. Weighted kappa (κ) statistics were used to assess reliability.Results: Based on the observers and Trium's classification, κ was 0.78 and the strength of agreement level was substantial. The obstetricians and Trium mostly agreed on the variability and baseline data. However, κ of each deceleration was approximately 0.65 (0.63-0.66), with substantial strength of agreement.Conclusion: Based on the obstetricians and Trium's interpretation, the latter was found to be excellent for FHR interpretation. However, it was difficult for Trium to interpret specific waveform patterns. Therefore, clinical staff should understand these characteristics to more sensitively evaluate the fetal well-being.

Characteristics of fetal and maternal heart rate tracings during labor: A prospective observational study.

BACKGROUND: Fetal well-being is assured during labor and delivery with the employment of electronic fetal heart monitoring (EFHM). In uncommon instances, maternal heart rate (MHR) instead of fetal heart rate (FHR) can be the source of signals on monitors (signal ambiguity) leading to erroneous interpretation and management. Information about MHR characteristics are comparatively inadequate. We aim to analyze and compare MHR and FHR characteristics during the first and second stages of labor. METHODS: A prospective cohort study was conducted in a single tertiary care center during a one year period. Fifty one healthy full term women with singleton pregnancies during labor were enrolled. Uterine contractions, MHR and FHR were recorded simultaneously during both stages of labor by monitors designed for twin gestation. RESULTS: When compared to FHR, MHR had significantly lower baseline rate during 1st and 2nd stages (p < 0.0001). It demonstrated also more marked beat-to-beat variability during both stages (p < 0.0001). MHR showed significantly more accelerations (p = 0.03 and p = 0.008) and less decelerations (p < 0.0001 and p = 0.021) during 1st and 2nd stages respectively. CONCLUSIONS: All characteristic parameters and patterns produced by FHR could be mimicked by MHR as well, though, at different frequencies. Understanding EFHM patterns suspected to be MHR artefacts and the employment of modern monitors that simultaneously obtain and display FHR and MHR can unmask ambiguity and avert related misinterpretation problems. Similar studies should be conducted in high-risk groups where the potential for fetal hypoxia/acidosis is increased.

Intrauterine resuscitation during the second stage of term labour by maternal hyperoxygenation versus conventional care: study protocol for a randomised controlled trial (INTEREST O2).

BACKGROUND: Perinatal asphyxia is, even in developed countries, one the major causes of neonatal morbidity and mortality. Therefore, if foetal distress during labour is suspected, one should try to restore foetal oxygen levels or aim for immediate delivery. However, studies on the effect of intrauterine resuscitation during labour are scarce. We designed a randomised controlled trial to investigate the effect of maternal hyperoxygenation on the foetal condition. In this study, maternal hyperoxygenation is induced for the treatment of foetal distress during the second stage of term labour. METHODS/DESIGN: This study is a single-centre randomised controlled trial being performed in a tertiary hospital in The Netherlands. From among cases of a suboptimal or abnormal foetal heart rate pattern during the second stage of term labour, a total of 116 patients will be randomised to the control group, where normal care is provided, or to the intervention group, where before normal care 100% oxygen is supplied to the mother by a non-rebreathing mask until delivery. The primary outcome is change in foetal heart rate pattern. Secondary outcomes are Apgar score, mode of delivery, admission to the neonatal intensive care unit and maternal side effects. In addition, blood gas values and malondialdehyde are determined in umbilical cord blood. DISCUSSION: This study will be the first randomised controlled trial to investigate the effect of maternal hyperoxygenation for foetal distress during labour. This intervention should be recommended only as a treatment for intrapartum foetal distress, when improvement of the foetal condition is likely and outweighs maternal and neonatal side effects. TRIAL REGISTRATION: EudraCT, 2015-001654-15; registered on 3 April 2015. Dutch Trial Register, NTR5461; registered on 20 October 2015.

The temporal effect of Category II fetal monitoring on neonatal outcomes.

OBJECTIVE: To correlate the duration of Category II cardiotocograms (CTG) with adverse neonatal outcomes associated with perinatal asphyxia and determine the duration before fetal compromise. STUDY DESIGN: This retrospective, observational study used electronic medical record data from a cohort of 271 patients, delivered by C-section due to non-reassuring fetal heart rate, at a tertiary medical center, from 2015 through 2017. Duration of Category II CTG, variability, tachycardia and deceleration frequency were analyzed and correlated to immediate postnatal outcomes. including cord pH ≤ 7, cord base excess >12, 1- and 5-min Apgar scores ≤7, need for ventilation, need for chest compressions, NICU admission, hypoglycemia and convulsions. Intrapartum fever and meconium stained amniotic fluid were correlated to the same outcomes. Categorical and continuous variables were analyzed using chi-square and t-tests, respectively. P < 0.05 was considered significant. RESULTS: The mean duration of Category II CTG was 146 min (range 17-553). Longer duration did not result in increased rates of adverse neonatal outcomes. In contrast, reduced fetal heart rate (FHR) variability, fetal tachycardia and intrapartum fever did show increased rates of adverse neonatal outcomes, as follows: patients exhibiting reduced vs. normal (FHR) variability had 12.9% vs. 1.4% cord pH ≤ 7, P = 0.006 and 12.5% vs. 1.3% cord BE > 12, P = 0.004: patients with fetal tachycardia vs. normal baseline FHR exhibited 48% vs. 17.9% 1-minute Apgar score ≤7, P = 0.0004; 8% vs. 0.8% 5-minute Apgar score ≤7, P = 0.04; and 48% vs. 18.7% ventilation support, P < 0.001; patients with intrapartum fever vs. normal temperature, cord BE > 12 was seen in 9.7% vs. 1.7%, P = 0.035; 1-minute Apgar score was ≤7 in 35.5% vs. 18.7%, P = 0.03; 5-minute Apgar score ≤7 in 9.7% vs. 0.4%, P = 0.005; need for ventilation in 35.5% vs. 19.6%, P = 0.042; need for chest compressions in 6.45% vs. none, P = 0.013; and NICU admission in 12.9% vs. 2.5%, P = 0.018. CONCLUSIONS: Our results suggest that the duration of Category II CTG alone does not appear to predict perinatal asphyxia. Parameters associated with perinatal asphyxia are reduced FHR variability, fetal tachycardia and intrapartum fever. Therefore, when contemplating intervention during labor to avoid fetal asphyxia, these parameters should be strongly considered.

Simulation of fetal heart rate variability with a mathematical model.

In the clinic, the cardiotocogram (CTG), the combined registration of fetal heart rate (FHR) and uterine contractions, is used to predict fetal well-being. Amongst others, fetal heart rate variability (FHRV) is an important indicator of fetal distress. In this study we add FHRV to our previously developed CTG simulation model, in order to improve its use as a research and educational tool. We implemented three sources of variability by applying either 1/f or white noise to the peripheral vascular resistance, baroreceptor output, or efferent vagal signal. Simulated FHR tracings were evaluated by visual inspection and spectral analysis. All power spectra showed a 1/f character, irrespective of noise type and source. The clinically observed peak near 0.1 Hz was only obtained by applying white noise to the different sources of variability. Similar power spectra were found when peripheral vascular resistance or baroreceptor output was used as source of variability. Sympathetic control predominantly influenced the low frequency power, while vagal control influenced both low and high frequency power. In contrast to clinical data, model results did not show an increase of FHRV during FHR decelerations. Still, addition of FHRV improves the applicability of the model as an educational and research tool.

Understanding fetal physiology and second line monitoring during labor.

Cardiotocography (CTG) is a technique used to monitor intrapartum fetal condition and is one of the most common obstetric procedures. Second line methods of fetal monitoring have been developed in an attempt to reduce unnecessary interventions due to continuous cardiotocography and to better identify fetuses at risk of intrapartum asphyxia. The acid-base balance of the fetus is evaluated by fetal blood scalp samples, the modification of the myocardial oxygenation by the fetal ECG ST-segment analysis (STAN) and the autonomic nervous system by the power spectral analysis of the fetal heart variability. To correctly interpret the features observed on CTG traces or second line methods, it seems important to understand normal physiology during labor and the compensatory mechanisms of the fetus in case of hypoxemia. Therefore, the aim of this review is first to describe fetal physiology during labor and then to explain the modification of the second line monitoring during labor.