A randomized controlled trial reducing cesarean delivery rates in China by introducing trial of labor after cesarean and electrohysterography.

OBJECTIVE: A cesarean delivery (CD) can affect health of both mother and child and future pregnancies. Since the abandonment of the one-child policy in China, obstetricians tend to perform a repeat CD rather than a trial of labor after cesarean (TOLAC). This study aims to reduce CD rates by increasing vaginal births after cesarean (VBAC) rates and introducing electrohysterography (EHG) for accurate monitoring. METHODS: In total, 82 women received counseling regarding TOLAC at the Shijiazhuang Sixth Hospital in China. Women opting for TOLAC were randomized for either external tocodynamometry (TOCO, i.e. standard care) or EHG. The primary outcome was the VBAC rate. Secondary outcomes were indications for CD, percentage of assisted vaginal deliveries, labor duration, maternal blood loss, complications and neonatal outcomes. RESULTS: After accounting for preterm delivery and dropouts, all counseled women opted for a TOLAC (100%). After randomization, 42 women were included in the TOCO-group and 37 in the EHG-group. Women did not receive pain medication and labor was not augmented with oxytocin. The VBAC rate was 71.4% in the TOCO-group, versus 78.4% in the EHG-group (p = .48). Birth was assisted with forceps in 11.9% of TOCO-group versus 2.7% of EHG-group (p = .21). One secondary CD (i.e. a shift from intended vaginal delivery to surgical delivery within the same labor) was performed because of a suspicion of uterine rupture (TOCO-group). Other indications for CD were: fetal distress, labor dystocia, fetal position, cephalopelvic disproportion. There were no significant differences in secondary study outcomes. No complications were reported. CONCLUSION: This study showed an average VBAC rate of 75%, without any complications, in a hospital with no previous experience with TOLAC. The VBAC rate with EHG-monitoring was higher than TOCO, although this difference was not significant. To demonstrate a significant difference, larger clinical studies are necessary. TRIAL REGISTRATION: The Daily Board of the Medical Ethics Committee of The Maternal and Child Hospital of Shijiazhuang approved the study protocol (number 20171018, Dutch Trial Register NL8199).

Multi-channel electrohysterography enabled uterine contraction characterization and its effect in delivery assessment.

Uterine contractions are routinely monitored by tocodynamometer (TOCO) at late stage of pregnancy to predict the onset of labor. However, TOCO reveals no information on the synchrony and coherence of contractions, which are important contributors to a successful delivery. The electrohysterography (EHG) is a recording of the electrical activities that trigger the local muscles to contract. The spatial-temporal information embedded in multiple channel EHG signals make them ideal for characterizing the synchrony and coherence of uterine contraction. To proceed, contractile time-windows are identified from TOCO signals and are then used to segment out the simultaneously recorded EHG signals of different channels. We construct sample entropy SamEn and Concordance Correlation based feature ψ from these EHG segments to quantify the synchrony and coherence of contraction. To test the effectiveness of the proposed method, 122 EHG recordings in the Icelandic EHG database were divided into two groups according to the time difference between the gestational ages at recording and at delivery (TTD). Both SamEn and ψ show clear difference in the two groups (p<10-5) even when measurements were made 120 h before delivery. Receiver operating characteristic curve analysis of these two features gave AUC values of 0.834 and 0.726 for discriminating imminent labor defined with TTD ≤ 24 h. The SamEn was significantly smaller in women (0.1433) of imminent labor group than in women (0.3774) of the pregnancy group. Using an optimal cutoff value of SamEn to identify imminent labor gives sensitivity, specificity, and accuracy as high as 0.909, 0.712 and 0.743, respectively. These results demonstrate superiority in comparing to the existing SOTA methods. This study is the first research work focusing on characterizing the synchrony property of contractions from the electrohysterography signals. Despite the very limited dataset used in the validation process, the promising results open a new direction to the use of electrohysterography in obstetrics.

Assessment of uterine contractions in labor and delivery.

Normal labor and delivery are dependent on the presence of regular and effective contractions of the uterine myometrium. The mechanisms responsible for the initiation and maintenance of adequate and synchronized uterine activity that are necessary for labor and delivery result from a complex interplay of hormonal, mechanical, and electrical factors that have not yet been fully elucidated. Monitoring uterine activity during term labor and in suspected preterm labor is an important component of obstetrical care because cases of inadequate and excessive uterine activity can be associated with substantial maternal and neonatal morbidity and mortality. Inadequate labor progress is a common challenge encountered in intrapartum care, with labor dystocia being the most common indication for cesarean deliveries performed during labor. Hereafter, an accurate assessment of uterine activity during labor can assist in the management of protracted labor by diagnosing inadequate uterine activity and facilitating the titration of uterotonic medications before a trial of labor is prematurely terminated. Conversely, the ability to diagnose unwanted or excessive uterine activity is also critical in cases of threatened preterm labor, tachysystole, or patients undergoing a trial of labor after cesarean delivery. Knowledge of uterine activity in these cases may guide the use of tocolytic medications or raise suspicion of uterine rupture. Current diagnostic capabilities are less than optimal, hindering the medical management of term and preterm labor. Currently, different methods exist for evaluating uterine activity during labor, including manual palpation, external tocodynamometry, intrauterine pressure monitoring, and electrical uterine myometrial activity tracing. Legacy uterine monitoring techniques have advantages and limitations. External tocodynamometry is the most widespread tool in clinical use owing to its noninvasive nature and its ability to time contractions against the fetal heart rate monitor. However, it does not provide information regarding the strength of uterine contractions and is limited by signal loss with maternal movements. Conversely, the intrauterine pressure catheter quantifies the strength of uterine contractions; however, its use is limited by its invasiveness, risk for complications, and limited additive value in all but few clinical scenarios. New monitoring methods are being used, such as electrical uterine monitoring, which is noninvasive and does not require ruptured membranes. Electrical uterine monitoring has yet to be incorporated into common clinical practice because of lack of access to this technology, its high cost, and the need for appropriate training of clinical staff. Further work needs to be done to increase the accessibility and implementation of this technique by experts, and further research is needed to implement new practical and useful methods. This review describes current clinical tools for uterine activity assessment during labor and discusses their advantages and shortcomings. The review also summarizes current knowledge regarding novel technologies for monitoring uterine contractions that are not yet in widespread use, but are promising and could help improve our understanding of the physiology of labor, delivery, and preterm labor, and ultimately enhance patient care.

Uterine slow wave: directionality and changes with imminent delivery.

Objective.The slow wave (SW) of the electrohysterogram (EHG) may contain relevant information on the electrophysiological condition of the uterus throughout pregnancy and labor. Our aim was to assess differences in the SW as regards the imminence of labor and the directionality of uterine myoelectrical activity.Approach. The SW of the EHG was extracted from the signals of the Icelandic 16-electrode EHG database in the bandwidth [5, 30] mHz and its power, spectral content, complexity and synchronization between the horizontal (X) and vertical (Y) directions were characterized by the root mean square (RMS), dominant frequency (domF), sample entropy (SampEn) and maximum cross-correlation (CCmax) of the signals, respectively. Significant differences between parameters at time-to-delivery (TTD) ≤7 versus >7 days and between the horizontal versus vertical directions were assessed.Main results.The SW power significantly increased in both directions as labor approached (TTD ≤ 7d versus >7d (mean±SD):RMSx = 0.12 ± 0.10 versus 0.08 ± 0.06 mV;RMSy = 0.12 ± 0.09 versus 0.08 ± 0.05 mV), as well as the dominant frequency in the horizontal direction (domFx= 9.1 ± 1.3 versus 8.5 ± 1.2mHz) and the synchronization between both directions (CCmax= 0.44 ± 0.16 versus 0.36 ± 0.14). Furthermore, its complexity decreased in the vertical direction (SampEny= 6.13·10-2 ± 8.7·10-3versus 6.50·10-2 ± 8.3·10-3), suggesting a higher cell-to-cell electrical coupling. Whereas there were no differences between the SW features in both directions in the general population, statistically significant differences were obtained between them in individuals in many cases.Significance.Our results suggest that the SW of the EHG is related to bioelectrical events in the uterus and could provide objective information to clinicians in challenging obstetric scenarios.

Recognition of uterine contractions with electrohysterogram and exploring the best electrode combination.

BACKGROUND: As an essential indicator of labour and delivery, uterine contraction (UC) can be detected by manual palpation, external tocodynamometry and internal uterine pressure catheter. However, these methods are not applicable for long-term monitoring. OBJECTIVE: This paper aims to recognize UCs with electrohysterogram (EHG) and find the best electrode combination with fewer electrodes. METHODS: 112 EHG recordings were collected by our bespoke device in our study. Thirteen features were extracted from EHG segments of UC and non-UC. Four classifiers of the decision tree, support vector machine (SVM), artificial neural network, and convolutional neural network were established to identify UCs. The optimal classifier among them was determined by comparing their classification results. The optimal classifier was applied to evaluate all the possible electrode combinations with one to eight electrodes. RESULTS: The results showed that SVM achieved the best classification capability. With SVM, the combination of electrodes on the right part of the uterine fundus and around the uterine body's median axis achieved the overall best performance. CONCLUSIONS: The optimal electrode combination with fewer electrodes was confirmed to improve the clinical application for long-term monitoring of UCs.

Novel uterine contraction monitoring to enable remote, self-administered nonstress testing.

BACKGROUND: The serial fetal monitoring recommended for women with high-risk pregnancies places a substantial burden on the patient, often disproportionately affecting underprivileged and rural populations. A telehealth solution that can empower pregnant women to obtain recommended fetal surveillance from the comfort of their own home has the potential to promote health equity and improve outcomes. We have previously validated a novel, wireless pregnancy monitor that can remotely capture fetal and maternal heart rates. However, such a device must also detect uterine contractions if it is to be used to robustly conduct remote nonstress tests. OBJECTIVE: This study aimed to describe and validate a novel algorithm that uses biopotential and acoustic signals to noninvasively detect uterine contractions via a wireless pregnancy monitor. STUDY DESIGN: A prospective, open-label, 2-center study evaluated simultaneous detection of uterine contractions by the wireless pregnancy monitor and an intrauterine pressure catheter in women carrying singleton pregnancies at ≥32 0/7 weeks' gestation who were in the first stage of labor (ClinicalTrials.gov Identifier: NCT03889405). The study consisted of a training phase and a validation phase. Simultaneous recordings from each device were passively acquired for 30 to 60 minutes. In a subset of the monitoring sessions in the validation phase, tocodynamometry was also deployed. Three maternal-fetal medicine specialists, blinded to the data source, identified and marked contractions in all modalities. The positive agreement and false-positive rates of both the wireless monitor and tocodynamometry were calculated and compared with that of the intrauterine pressure catheter. RESULTS: A total of 118 participants were included, 40 in the training phase and 78 in the validation phase (of which 39 of 78 participants were monitored simultaneously by all 3 devices) at a mean gestational age of 38.6 weeks. In the training phase, the positive agreement for the wireless monitor was 88.4% (1440 of 1692 contractions), with a false-positive rate of 15.3% (260/1700). In the validation phase, using the refined and finalized algorithm, the positive agreement for the wireless pregnancy monitor was 84.8% (2722/3210), with a false-positive rate of 24.8% (897/3619). For the subgroup who were monitored only with the wireless monitor and intrauterine pressure catheter, the positive agreement was 89.0% (1191/1338), with a similar false-positive rate of 25.4% (406/1597). For the subgroup monitored by all 3 devices, the positive agreement for the wireless monitor was significantly better than for tocodynamometry (P<.0001), whereas the false-positive rate was significantly higher (P<.0001). Unlike tocodynamometry, whose positive agreement was significantly reduced in the group with obesity compared with the group with normal weight (P=.024), the positive agreement of the wireless monitor did not vary across the body mass index groups. CONCLUSION: This novel method to noninvasively monitor uterine activity, via a wireless pregnancy monitoring device designed for self-administration at home, was more accurate than the commonly used tocodynamometry and unaffected by body mass index. Together with the previously reported remote fetal heart rate monitoring capabilities, this added ability to detect uterine contractions has created a complete telehealth solution for remote administration of nonstress tests.

Métodos anticonceptivos elegidos por mujeres después de aborto en un hospital público de Honduras / Contraceptive methods chosen by women after abortion in a public hospital in Honduras

Antecedentes: La tasa de embarazos no planeados en Latinoamérica está entre las más altas del mundo. Las adoles- centes están entre los grupos más vulnerables para embarazos no planeados con porcentajes de 32% a 45%. Objetivo: Describir los factores asociados a la elección de un anticonceptivo por las mujeres después de un aborto, en el Hospital Dr. Roberto Suazo Córdova, La Paz, Honduras, en el periodo de julio 2017 a junio 2019. Método: Estudio retrospectivo descriptivo. Los datos fueron obtenidos usando el Sistema Informático Perinatal Aborto (SIP Aborto) en la versión SIP 4.16. Resultados: El 50.0% (67/134) de las adolescentes y 50.1% (281/550) de las mayores de 19 años eligieron un anticonceptivo postaborto. El inicio del anticonceptivo se relacionó con antecedente de aborto (p=0.006). Uso previo de anticonceptivos (p=0.007). Los anticonceptivos más elegidos fueron: Acetato de medroxiprogesterona, anticonceptivos orales combinados y condón. La elección del anticonceptivo se relacionó con evacuación instrumental del aborto (p=0.022) en adolescentes y (p=0.000) en mayores de 19 años. Se eligieron menos los mé- todos reversibles de acción prolongada. Discusión: La elección anticonceptiva postaborto fue baja. El inicio de anticonceptivos se relacionó con antecedente de aborto, uso previo de anticoncepti- vos y evacuación instrumental. Los anticonceptivos más elegidos fueron los temporales de acción corta y los menos elegidos, los temporales de acción prolongada. Se debe fortalecer el acceso a información, mejorar la consejería, garantizar acceso y disponibili- dad de anticonceptivos sobre todo de acción prolongada para ase- gurar el apego al método anticonceptivo...(AU)

The assessment of selected parameters of bioelectric and mechanical activity of the uterus during pharmacologic treatment of threatening preterm delivery.

OBJECTIVES: To analyze and compare the bioelectric and mechanical activity of the uterus in pregnant women with threatening preterm delivery treated with tocolysis. Additionally, auxiliary parameters of the bioelectric signal, as registered by electrohysterography and characteristic only for this method, were measured and analyzed. MATERIAL AND METHODS: Forty-five women with pregnancies from 24 to 36 weeks of gestation with typical clinical symptoms of threatening preterm delivery were given tocolytic therapy. Registration and analysis of bioelectric activity with electrohysterography was performed simultaneously with registration and analysis of mechanical activity with tocography. RESULTS: After administration of tocolytic treatment, the presence of bioelectric activity was accompanied by the lack of or minimal occurrence of mechanical activity. All parameters of contraction recorded by electrohysterography had significantly greater values than those recorded by tocography. CONCLUSIONS: Measurement of bioelectric activity is more sensitive than measurement of mechanical activity of the uterus. Elevated bioelectric activity of the uterine muscle was observed despite the use of tocolysis, a lack of symptoms of threatening preterm delivery, as well as a lack of contraction in tocography. The presence of bioelectric activity may precede the occurrence of mechanical activity of the uterus, but further research is required on larger groups of patients.

Automatic recognition of uterine contractions with electrohysterogram signals based on the zero-crossing rate.

Uterine contraction (UC) is an essential clinical indicator in the progress of labour and delivery. Electrohysterogram (EHG) signals recorded on the abdomen of pregnant women reflect the uterine electrical activity. This study proposes a novel algorithm for automatic recognition of UCs with EHG signals to improve the accuracy of detecting UCs. EHG signals by electrodes, the tension of the abdominal wall by tocodynamometry (TOCO) and maternal perception were recorded simultaneously in 54 pregnant women. The zero-crossing rate (ZCR) of the EHG signal and its power were calculated to modulate the raw EHG signal and highlight the EHG bursts. Then the envelope was extracted from the modulated EHG for UC recognition. Besides, UC was also detected by the conventional TOCO signal. Taking maternal perception as a reference, the UCs recognized by EHG and TOCO were evaluated with the sensitivity, positive predictive value (PPV), and UC parameters. The results show that the sensitivity and PPV are 87.8% and 93.18% for EHG, and 84.04% and 90.89% for TOCO. EHG detected a larger number of UCs than TOCO, which is closer to maternal perception. The duration and frequency of UC obtained from EHG and TOCO were not significantly different (p > 0.05). In conclusion, the proposed UC recognition algorithm has high accuracy and simple calculation which could be used for real-time analysis of EHG signals and long-term monitoring of UCs.

M-mode Ultrasound Scan as a Potential Alternative Technique for Monitoring Uterine Contractions in Obese Patients.

We investigate motion mode (M-mode) ultrasound scan as a potential non-invasive uterine monitoring technique and compare its contraction characteristics with external tocodynamometry (TOCO). This prospective diagnostic accuracy study included 39 term pregnant woman in active spontaneous labor. M-mode and TOCO were simultaneously performed and uterine contraction characteristics and consistency were compared quantitatively and visually. The results identified a 71.5% ± 35.3% uterine wall thickening during uterine contractions on M-mode. Uterine monitoring with M-mode had a consistency rate of 88.7% ± 6.9% with conventional TOCO method. During 20-min monitoring, the number of detected contractions was significantly higher (p < 0.001) in M-mode (8.2 ± 1.2) than TOCO (7.4 ± 1.5). As for the mean value of the duration of a contraction (seconds), it was significantly shorter (p < 0.001) in M-mode (38.5 ± 3.5) than TOCO (49.2 ± 4.1). For M-mode, the number of detected contractions had a negative but insignificant correlation with the body mass index (BMI) (r = - 0.25 [- 0.52, 0.07], p = 0.127) and the subcutaneous tissue thickness (STT) (r = - 0.21 [- 0.49, 0.11], p = 0.200). As for TOCO, the contractions had a negative and significant correlation with BMI (r = - 0.41 [- 0.64, - 0.11], p = 0.009) and negative and insignificant correlation with STT (r = - 0.26 [- 0.54, 0.06], p = 0.104). The evidence suggests that contraction detection with M-mode is a promising non-invasive technique for uterine monitoring. The preliminary analysis finds that contraction detection is not affected by BMI or STT. With future sensitivity studies, and improvements in image-processing and software technologies, the proposed technique promises to be a viable alternative to existing techniques, especially for obese patients.

Clinical evaluation of labor: an evidence- and experience-based approach.

During labor mother and fetus are evaluated at intervals to assess their well-being and determine how the labor is progressing. These assessments require skillful physical diagnosis and the ability to translate the acquired information into meaningful prognostic decision-making. We describe a coordinated approach to the assessment of labor. Graphing of serial measurements of cervical dilatation and fetal station creates "labor curves," which provide diagnostic and prognostic information. Based on these curves we recognize nine discrete labor abnormalities. Many may be related to insufficient or disordered contractile mechanisms. Several factors are strongly associated with development of labor disorders, including cephalopelvic disproportion, excess analgesia, fetal malpositions, intrauterine infection, and maternal obesity. Clinical cephalopelvimetry involves assessing pelvic traits and predicting their effects on labor. These observations must be integrated with information derived from the labor curves. Exogenous oxytocin is widely used. It has a high therapeutic index, but is easily misused. Oxytocin treatment should be restricted to situations in which its potential benefits clearly outweigh its risks. This requires there be a documented labor dysfunction or a legitimate medical reason to shorten the labor. Normal labor and delivery pose little risk to a healthy fetus; but dysfunctional labors, especially if stimulated excessively by oxytocin or terminated by complex operative vaginal delivery, have the potential for considerable harm. Conscientiously implemented, the approach to the evaluation of labor outlined in this review will result in a reasonable cesarean rate and minimize risks that may accrue from the labor and delivery process.

Intrauterine versus external tocodynamometry in monitoring labour: a randomised controlled clinical trial.

OBJECTIVE: To investigate whether the use of intrauterine tocodynamometry versus external tocodynamometry (IT versus ET) during labour reduces operative deliveries and improves newborn outcome. As IT provides more accurate information on labour contractions, the hypothesis was that it may more appropriately guide oxytocin use than ET. DESIGN: Randomised controlled trial. SETTING: Two labour wards, in a university tertiary hospital and a central hospital. POPULATION: A total of 1504 parturients with singleton pregnancies, gestational age ≥37 weeks and fetus in cephalic position: 269 women with uterine scars, 889 nulliparas and 346 parous women with oxytocin augmentation. METHODS: Participants underwent IT (n = 736) or ET (n = 768) during the active first stage of labour. MAIN OUTCOME MEASURES: Primary outcome: rate of operative deliveries. SECONDARY OUTCOMES: duration of labour, amount of oxytocin given, adverse neonatal outcomes. RESULTS: Operative delivery rates were 26.9% (IT) and 25.9% (ET) (odds ratio 1.05, 95% CI 0.84-1.32, P = 0.663). The ET to IT conversion rate was 31%. We found no differences in secondary outcomes (IT versus ET). IT reduced oxytocin use during labours with signs of fetal distress, and trial of labour after caesarean section. CONCLUSIONS: IT did not reduce the rate of operative deliveries, use of oxytocin, or adverse neonatal outcomes, and it did not shorten labour duration. TWEETABLE ABSTRACT: IT (versus ET) reduced oxytocin use in high-risk labours but did not influence operative delivery rate or adverse neonatal outcomes.

Use of the partograph - Current thinking.

The partograph (sometimes called partogram) is a labour monitoring tool that is used in countries worldwide to enable early detection of complications, so that referral, action or closer observations can ensue. While the partograph has received global support, from health professionals, there are concerns that it has not reached its full potential in improving clinical outcomes. This has resulted in several variations of the tool and a plethora of studies aimed at exploring the barriers and facilitators to its use. In this chapter, we will discuss the history of the partograph, outlining how it has evolved over time. We will also suggest reasons why the tool may not be meeting the needs of all practitioners. In particular, we will explore partograph use as a complex intervention, suggesting that its success is likely to be dependent on multiple contextual factors.

Safety of misoprostol vaginal insert for labor induction using standard vs. adjusted retrieval criteria: a comparative cohort study.

Objective To compare the safety of misoprostol vaginal insert (MVI) for labor induction using standard and adjusted criteria. Methods This was a single-center, comparative cohort study of 138 pregnant women ≥37/0 weeks undergoing labor induction with MVI using standard (69 women; administration for up to 24 h; MVI-24) or adjusted (69 women; administration for up to 10 h; MVI-10) criteria in a tertiary academic center in Germany. The main maternal safety outcomes were the rate of tachysystole and rate of tachysystole requiring tocolysis. Neonatal safety assessments included Apgar score at 5 min and postpartum arterial fetal pH. Results Uterine tachysystole occurred in more women in the MVI-24 group compared with the MVI-10 group [47.8% vs. 25.5%; P = 0.001; relative risk (RR) 2.36 (95% confidence interval [CI]: 1.39-4.00)] and as did uterine tachysystole requiring tocolysis [MVI-24: 26.1% vs. MVI-10: 11.6%; P = 0.049; RR 2.25 (95% CI: 1.05-4.83)]. The mean 5-min Apgar scores were 9.64 for the MVI-24 group and 9.87 for the MVI-10 (P = 0.016). Low postpartum umbilical arterial pH values occurred more often in the MVI-24 compared with the MVI-10 group (pH 7.10-7.19: 26.1% vs. 20.3% and pH <7.10: 4.4% vs. 0.0%, respectively). Conclusion Adjusted retrieval criteria for MVI of up to 10 h exposure instead of the standard 24 h reduced uterine tachysystole and improved the neonatal outcome.

Contractions: Traditional concepts and their role in modern obstetrics.

Contractions are produced through a complex interplay of hormonal, mechanical, and electrical factors. In labor, contractions are measured using the Montevideo unit. Clinical considerations in labor wherein contraction assessment becomes paramount include the care of women whose labor is complicated by abnormal progress or tachysystole. In an era of obstetrics in which the high cesarean rate is a major issue of concern, there remain many questions as to how to best incorporate contraction monitoring into practice in order to optimize care. Technological advancement has led to the development on new modalities that can be used to study contraction physiology, and there may be an opportunity in the future to apply these methods for use in the clinical setting. This article also makes a case for the need to reevaluate the current measures of uterine contractile activity and the definition of contraction adequacy using updated definitions of normal labor progress.

New electrohysterogram-based estimators of intrauterine pressure signal, tonus and contraction peak for non-invasive labor monitoring.

BACKGROUND: Uterine activity monitoring is an essential part of managing the progress of pregnancy and labor. Although intrauterine pressure (IUP) is the only reliable method of estimating uterine mechanical activity, it is highly invasive. Since there is a direct relationship between the electrical and mechanical activity of uterine cells, surface electrohysterography (EHG) has become a noninvasive monitoring alternative. The Teager energy (TE) operator of the EHG signal has been used for IUP continuous pressure estimation, although its accuracy could be improved. We aimed to develop new optimized IUP estimation models for clinical application. APPROACH: We first considered enhancing the optimal estimation of IUP clinical features (maximum pressure and tonus) rather than optimizing the signal only (continuous pressure). An adaptive algorithm was also developed to deal with inter-patient variability. For each optimizing signal feature (continuous pressure, maximum pressure and tonus), individual (single patient), global (full database) and adaptive models were built to estimate the recorded IUP signal. The results were evaluated by computing the root mean square errors (RMSe): continuous pressure error (CPe), maximum pressure error (MPe) and tonus error (TOe). MAIN RESULTS: The continuous pressure global model yielded IUP estimates with Cpe = 14.61 mm Hg, MPe = 29.17 mm Hg and Toe = 7.8 mm Hg. The adaptive models significantly reduced errors to CPe = 11.88, MPe = 16.02 and Toe = 5.61 mm Hg. The EHG-based IUP estimates outperformed those from traditional tocographic recordings, which had significantly higher errors (CPe = 21.93, MPe = 26.97, and TOe = 13.96). SIGNIFICANCE: Our results show that adaptive models yield better IUP estimates than the traditional approaches and provide the best balance of the different errors computed for a better assessment of the labor progress and maternal and fetal well-being.

Is Prolonged Labor Managed Adequately in Rural Rwandan Hospitals?

Unnecessary interventions to manage prolonged labor may cause considerable maternal and perinatal ill-health. We explored how prolonged labor was managed in three rural Rwandan hospitals using a partograph. A retrospective chart review was done to assess whether (A) the action line on the partograph was reached or crossed, (B) artificial rupture of membranes (ARM) performed, (C) oxytocin augmentation instituted, and (D) vacuum extraction (VE) considered when in second stage of labor. Adequate management of prolonged labor was considered if three clinical criteria were fulfilled in the first and four in the second stage. Out of 7605 partographs, 299/7605 women (3.9%) were managed adequately and 1252/7605 women (16.5%) inadequately for prolonged labor. While 6054 women (79.6%) remained at the left of the alert line, still 1651/6054 (27.3%) received oxytocin augmentation unjustifiably. Amongst women whom were managed adequately for prolonged labor until their cervical dilatation plot reached or crossed the action line. In 115/299 women (38.5%), however, second stage of labor was reached but CS performed without a trial of VE. In 1252/7605 women (16.5%) management was inadequate, when their cervical dilatation plot reached between the alert and action lines, 495/1252 women (39.5%) did not reach the second stage of labor and remained left of the action line had their membranes ruptured and labor augmented, and gave birth by CS. CS was, however, also performed in 151/1252 women (12.1%) whose membranes were still intact. We recommend training for more appropriate decision-making during labor to prevent unnecessary CS and proper use of ARM, oxytocin augmentation and VE can be provided safely.

Development of Electrohysterogram Recording System for Monitoring Uterine Contraction.

Uterine contraction (UC) is an important clinical indictor for monitoring uterine activity. The purpose of this study is to develop a portable electrohysterogram (EHG) recording system (called PregCare) for monitoring UCs with EHG signals. The PregCare consisted of sensors, a signal acquisition device, and a computer with application software. Eight-channel EHG signals, the tocodynamometry (TOCO) signal, and maternal perception were recorded simultaneously by the signal acquisition device controlled by the computer via Bluetooth. PregCare was firstly evaluated by a signal simulator. Its relative error (RE) and coefficient of variation (CV) were calculated, and its agreement with the commercial instrument PowerLab was assessed by Bland-Altman plots. After that, PregCare was applied to 20 pregnant women in a hospital to record their EHG signals. These EHG signals were preprocessed and segmented into UCs and non-UCs. Then, the EHG features corresponding to UCs and non-UCs were extracted, respectively, including power spectral density (PSD), root mean square (RMS), peak frequency (PF), median frequency (MDF), and sample entropy (SamEn). One-way ANOVA was employed to assess the difference between UCs and non-UCs. The results show that RE and CV were less than 8% and 0.03%, respectively, which indicated the high accuracy and repeatability of PregCare. The small differences of mean and standard deviation indicated the high agreement between PregCare and PowerLab. Besides, the PSD of UCs was much larger than non-UCs between 0 and 0.7 Hz. RMS of UCs was significantly larger than non-UCs (p < 0.05). PF and SamEn of UCs were significantly smaller than non-UCs (p < 0.05). In conclusion, the developed EHG recording system was able to record EHG signals reliably. It has the advantages of portability, low power consumption, and wireless transmission, which can be used for long-term monitoring of UCs and prediction of the preterm delivery.

A novel modality for intrapartum fetal heart rate monitoring.

BACKGROUND: Intrapartum fetal heart rate (FHR) monitoring is well recommended during labor to assess fetal wellbeing. Though commonly used, the external Doppler and fetal scalp electrode monitor have significant shortcomings. Lately, non-invasive technologies were developed as possible alternatives. OBJECTIVE: The objective of this study is to compare the accuracy of FHR trace using novel Electronic Uterine Monitoring (EUM) to that of external Doppler and fetal scalp electrode monitor. MATERIAL AND METHODS: A comparative study conducted in a single tertiary medical center. Intrapartum FHR trace was recorded simultaneously using three different methods: internal fetal scalp electrode, external Doppler, and EUM. The latter, a multichannel electromyogram (EMG) device acquires a uterine signal and maternal and fetal electrocardiograms. FHR traces obtained from all devices during the first and second stages of labor were analyzed. Positive percent of agreement (PPA) and accuracy (by measuring root means square error between observed and predicted values) of EUM and external Doppler were both compared to internal scalp electrode monitoring. A Bland-Altman agreement plot was used to compare the differences in FHR trace between all modalities. For momentary recordings of fetal heart rate <110 bpm or >160 bpm level of agreement, sensitivity, and specificity were also evaluated. RESULTS: Overall, 712,800 FHR momentary recordings were obtained from 33 parturients. Although both EUM and external Doppler highly correlated with internal scalp electrode monitoring (r2 = 0.98, p < .001 for both methods), the accuracy of EUM was significantly higher than external Doppler (99.0% versus 96.6%, p < .001). In addition, for fetal heart rate <110 bpm or >160 bpm, the PPA, sensitivity, and specificity of EUM as compared with internal fetal scalp electrode, were significantly greater than those of external Doppler (p < .001). CONCLUSION: Intrapartum FHR using EUM is both valid and accurate, yielding higher correlations with internal scalp electrode monitoring than external Doppler. As such, it may provide a good framework for non-invasive evaluation of intrapartum FHR.

Update on uterine tachysystole.

Uterine tachysystole (TS) is a potentially significant intrapartum complication seen most commonly in induced or augmented labors but may also occur in women with spontaneous labor. When it occurs, maternal and perinatal complications can arise if not identified and managed promptly by obstetric care providers. Over recent years, new definitions of the condition have facilitated further research into the field, which has been synthesized to inform clinical management guidelines and protocols. We propose a set of recommendations pertaining to TS in line with contemporary evidence and obstetric practice.