Unsupervised denoising of the non-invasive fetal electrocardiogram with sparse domain Kalman filtering and vectorcardiographic loop alignment.

Even though the electrocardiogram (ECG) has potential to be used as a monitoring or diagnostic tool for fetuses, the use of non-invasive fetal ECG is complicated by relatively high amounts of noise and fetal movement during the measurement. Moreover, machine learning-based solutions to this problem struggle with the lack of clean reference data, which is difficult to obtain. To solve these problems, this work aims to incorporate fetal rotation correction with electrocardiogram denoising into a single unsupervised end-to-end trainable method. This method uses the vectorcardiogram (VCG), a 3-dimensional representation of the ECG, as an input and extends the previously introduced Kalman-LISTA method with a Kalman filter for the estimation of fetal rotation, applying denoising to the rotation-corrected VCG. The resulting method was shown to outperform denoising auto-encoders by more than 3dB while achieving a rotation tracking error of less than 33°. Furthermore, the method was shown to be robust to a difference in signal to noise ratio between electrocardiographic leads and different rotational velocities. Future work should aim at improving the method's generalizability and evaluation of the method's value in research and clinical use. This value might not only derive from the denoised fetal ECG, but from the method's objective measure for fetal rotation as well due to it's potential for early detection of fetal complications.

Early prediction of gestational diabetes mellitus using maternal demographic and clinical risk factors.

OBJECTIVE: To build and validate an early risk prediction model for gestational diabetes mellitus (GDM) based on first-trimester electronic medical records including maternal demographic and clinical risk factors. METHODS: To develop and validate a GDM prediction model, two datasets were used in this retrospective study. One included data of 14,015 pregnant women from Máxima Medical Center (MMC) in the Netherlands. The other was from an open-source database nuMoM2b including data of 10,038 nulliparous pregnant women, collected in the USA. Widely used maternal demographic and clinical risk factors were considered for modeling. A GDM prediction model based on elastic net logistic regression was trained from a subset of the MMC data. Internal validation was performed on the remaining MMC data to evaluate the model performance. For external validation, the prediction model was tested on an external test set from the nuMoM2b dataset. RESULTS: An area under the receiver-operating-characteristic curve (AUC) of 0.81 was achieved for early prediction of GDM on the MMC test data, comparable to the performance reported in previous studies. While the performance markedly decreased to an AUC of 0.69 when testing the MMC-based model on the external nuMoM2b test data, close to the performance trained and tested on the nuMoM2b dataset only (AUC = 0.70).

Transferring an extremely premature infant to an extra-uterine life support system: a prospective view on the obstetric procedure.

To improve care for extremely premature infants, the development of an extrauterine environment for newborn development is being researched, known as Artificial Placenta and Artificial Womb (APAW) technology. APAW facilitates extended development in a liquid-filled incubator with oxygen and nutrient supply through an oxygenator connected to the umbilical vessels. This setup is intended to provide the optimal environment for further development, allowing further lung maturation by delaying gas exposure to oxygen. This innovative treatment necessitates interventions in obstetric procedures to transfer an infant from the native to an artificial womb, while preventing fetal-to-neonatal transition. In this narrative review we analyze relevant fetal physiology literature, provide an overview of insights from APAW studies, and identify considerations for the obstetric procedure from the native uterus to an APAW system. Lastly, this review provides suggestions to improve sterility, fetal and maternal well-being, and the prevention of neonatal transition.

Simulation-Based Training in Emergency Obstetric Care in Sub-Saharan and Central Africa: A Scoping Review.

Background: Every day approximately 810 women die from complications related to pregnancy and childbirth worldwide. Around two thirds of these deaths happen in sub-Saharan Africa. One of the strategies to decrease these numbers is improving the quality of care by emergency obstetric simulation-based training. The effectiveness of such training programs depends on the program's instructional design. Objective: This review gives an overview of studies about emergency obstetric simulation-based training and examines the applied instructional design of the training programs in sub-Saharan and Central Africa. Methods: We searched Medline, Embase and Cochrane Library from inception to May 2021. Peer-reviewed articles on emergency obstetric, postgraduate, simulation-based training in sub-Saharan and Central Africa were included. Outcome measures were categorized based on Kirkpatrick's levels of training evaluation. The instructional design was evaluated by using the ID-SIM questionnaire. Findings: In total, 47 studies met the inclusion criteria. Evaluation on Kirkpatrick level 1 showed positive reactions in 18 studies. Challenges and recommendations were considered. Results on knowledge, skills, and predictors for these results (Kirkpatrick level 2) were described in 29 studies. Retention as well as decay of knowledge and skills over time were presented. Results at Kirkpatrick level 3 were measured in 12 studies of which seven studies demonstrated improvements of skills on-the-job. Improvements of maternal and neonatal outcomes were described in fifteen studies and three studies reported on cost-estimations for training rollout (Kirkpatrick level 4). Instructional design items were heterogeneously applied and described. Conclusions: Results of 47 studies indicate evidence that simulation-based training in sub-Saharan and Central Africa can have a positive impact across all four levels of Kirkpatrick's training evaluation model. However, results were not consistent across all studies and the effects vary over time. A detailed description of instructional design features in future publications on simulation-based training will contribute to a deeper understanding of the underlying mechanisms that determine why certain training programs are more effective in improving maternal and neonatal healthcare outcomes than other.

Detection of postpartum uterine activity with electrohysterography.

OBJECTIVE: Uterine contractions are essential for childbirth, but also for expulsion of the placenta and for limiting postpartum blood loss. Postpartum hemorrhage is associated with almost 25% of the maternal deaths worldwide and the leading cause of maternal death in most low-income countries. Little is known about the physiology of the uterus postpartum, particularly due to the lack of an accurate measurement tool. The primary objective of this pilot study is to explore the potential of using electrohysterography to detect postpartum uterine contractions. If postpartum uterine activity can be objectified, this could contribute to understanding the physiology of the uterus and improve diagnosis and treatment of postpartum hemorrhage. STUDY DESIGN: In this observational study we included women aiming for a vaginal birth in two large maternity clinics in the Netherlands, Amphia Hospital Breda (group A, N2018-0161) and Máxima Medical Center Veldhoven (group B, N17.149). An electrode patch was placed on the maternal abdomen to record real-time electrical uterine activity until one hour postpartum continuously. In group A, the placement of the patch was lower than in group B. For analysis, tracings were divided into five different phases (1: dilatation until start pushing, 2: from start pushing until childbirth, 3: from childbirth until placental expulsion, 4: first hour after placental expulsion and 5: after one hour postpartum). Readability, signal quality and contraction frequency per hour were assessed. Additionally, patient satisfaction was evaluated through a survey. RESULTS: In total 91 pregnant women were included of whom 45 in group A and 46 women in group B. Complete registrations were obtained throughout the five labor phases with very little artefacts or signal loss. The readability of the tracings decreased after childbirth. A significantly better readability was found in tracings where the patch placement was lower on the abdomen for phases 4 and 5. Contraction frequency was highest during phase 2 and decreased towards phase 5. Women rated the satisfaction with electrohysterography as high and mostly did not notice the patch. CONCLUSION: It is possible to detect uterine activity postpartum with electrohysterography. Further investigation is recommended to improve diagnosis and treatment of postpartum hemorrhage.

Visualization of contractions: Evaluation of a new experience design concept to enhance the childbirth experience.

BACKGROUND: The purpose of this study was to develop and evaluate an innovative design proposition intended to help enhance the childbirth experience. The innovation consists of a smartphone application for birth preparation during pregnancy with information and coaching, in addition to a wall projection at the labor ward that visualizes the progress of labor based on uterine monitoring data. METHODS: We conducted a randomized controlled clinical pilot study. Singleton pregnant people pursuing a vaginal birth were recruited between 28 and 32 weeks of gestation and allocated to the intervention group (mobile application during the third trimester and wall projection at the labor ward) or to care as usual. Childbirth expectations and experiences were measured with validated questionnaires, which were completed at 32 and 36 weeks of gestation, immediately after birth, and at 4 weeks postpartum. Quantitative outcomes were analyzed and feedback about the proposition was evaluated using qualitative methods. RESULTS: The qualitative feedback from patients was largely positive; however, we could not detect any significant differences between the intervention and control groups about fear of childbirth and other outcome measures. CONCLUSION: In this pilot study, we evaluated a new experience design proposition for pregnancy and childbirth. This study generated data that will help to further improve and evaluate similar innovations in the future. This application may facilitate participatory care, promoting active involvement of parents in the healthcare processes of pregnancy and childbirth.

A review study of fetal circulatory models to develop a digital twin of a fetus in a perinatal life support system.

Background: Preterm birth is the main cause of neonatal deaths with increasing mortality and morbidity rates with decreasing GA at time of birth. Currently, premature infants are treated in neonatal intensive care units to support further development. However, the organs of, especially, extremely premature infants (born before 28 weeks of GA) are not mature enough to function optimally outside the womb. This is seen as the main cause of the high morbidity and mortality rates in this group. A liquid-filled incubator, a so-called PLS system, could potentially improve these numbers for extremely premature infants, since this system is designed to mimic the environment of the natural womb. To support the development and implementation of such a complex system and to interpret vital signals of the fetus during a PLS system operation, a digital twin is proposed. This mathematical model is connected with a manikin representing the digital and physical twin of the real-life PLS system. Before developing a digital twin of a fetus in a PLS system, its functional and technical requirements are defined and existing mathematical models are evaluated. Method and results: This review summarizes existing 0D and 1D fetal circulatory models that potentially could be (partly) adopted for integration in a digital twin of a fetus in a PLS system based on predefined requirements. The 0D models typically describe hemodynamics and/or oxygen transport during specific events, such as the transition from fetus to neonate. Furthermore, these models can be used to find hemodynamic differences between healthy and pathological physiological states. Rather than giving a global description of an entire cardiovascular system, some studies focus on specific organs or vessels. In order to analyze pressure and flow wave profiles in the cardiovascular system, transmission line or 1D models are used. As for now, these models do not include oxygen transport. Conclusion: This study shows that none of the models identified in literature meet all the requirements relevant for a digital twin of a fetus in a PLS system. Nevertheless, it does show the potential to develop this digital twin by integrating (parts) of models into a single model.

Ethical Development of Artificial Amniotic Sac and Placenta Technology: A Roadmap.

In this paper we present an initial roadmap for the ethical development and eventual implementation of artificial amniotic sac and placenta technology in clinical practice. We consider four elements of attention: (1) framing and societal dialogue; (2) value sensitive design, (3) research ethics and (4) ethical and legal research resulting in the development of an adequate moral and legal framework. Attention to all elements is a necessary requirement for ethically responsible development of this technology. The first element concerns the importance of framing and societal dialogue. This should involve all relevant stakeholders as well as the general public. We also identify the need to consider carefully the use of terminology and how this influences the understanding of the technology. Second, we elaborate on value sensitive design: the technology should be designed based upon the principles and values that emerge in the first step: societal dialogue. Third, research ethics deserves attention: for proceeding with first-in-human research with the technology, the process of recruiting and counseling eventual study participants and assuring their informed consent deserves careful attention. Fourth, ethical and legal research should concern the status of the subject in the AAPT. An eventual robust moral and legal framework for developing and implementing the technology in a research setting should combine all previous elements. With this roadmap, we emphasize the importance of stakeholder engagement throughout the process of developing and implementing the technology; this will contribute to ethically and responsibly innovating health care.

Evaluating the Instructional Design and Effect on Knowledge, Teamwork, and Skills of Technology-Enhanced Simulation-Based Training in Obstetrics in Uganda: Stepped-Wedge Cluster Randomized Trial.

BACKGROUND: Simulation-based training is a common strategy for improving the quality of facility-based maternity services and is often evaluated using Kirkpatrick's theoretical model. The results on the Kirkpatrick levels are closely related to the quality of the instructional design of a training program. The instructional design is generally defined as the "set of prescriptions for teaching methods to improve the quality of instruction with a goal of optimizing learning outcomes." OBJECTIVE: The aim of this study is to evaluate the instructional design of a technology-enhanced simulation-based training in obstetrics, the reaction of participants, and the effect on knowledge, teamwork, and skills in a low-income country. METHODS: A stepped-wedge cluster randomized trial was performed in a university hospital in Kampala, Uganda, with an annual delivery volume of over 31,000. In November 2014, a medical simulation center was installed with a full-body birthing simulator (Noelle S550, Gaumard Scientific), an interactive neonate (Simon S102 Newborn CPR Simulator, Gaumard Scientific), and an audio and video recording system. Twelve local obstetricians were trained and certified as medical simulation trainers. From 2014 to 2016, training was provided to 57 residents in groups of 6 to 9 students. Descriptive statistics were calculated for ten instructional design features of the training course measured by the 42-item ID-SIM (Instructional Design of a Simulation Improved by Monitoring). The Wilcoxon signed rank test was conducted to investigate the differences in scores on knowledge, the Clinical Teamwork Scale, and medical technical skills. RESULTS: The mean scores on the ten instructional design features ranged from 54.9 (95% CI 48.5-61.3) to 84.3 (95% CI 80.9-87.6) out of 100. The highest mean score was given on the feature feedback and the lowest scores on repetitive practice and controlled environment. The overall score for the training day was 92.8 out of 100 (95% CI 89.5-96.1). Knowledge improved significantly, with a test score of 63.4% (95% CI 60.7-66.1) before and 78.9% (95% CI 76.8-81.1) after the training (P<.001). The overall score on the 10-point Clinical Teamwork Scale was 6.0 (95% CI 4.4-7.6) before and 5.9 (95% CI 4.5-7.2) after the training (P=.78). Medical technical skills were scored at 55.5% (95% CI 47.2-63.8) before and 65.6% (95% CI 56.5-74.7) after training (P=.08). CONCLUSIONS: Most instructional design features of a technology-enhanced simulation-based training in obstetrics in a low-income country were scored high, although intervals were large. The overall score for the training day was high, and knowledge did improve after the training program, but no changes in teamwork and (most) medical technical skills were found. The lowest-scored instructional design features may be improved to achieve further learning aims. TRIAL REGISTRATION: ISRCTN Registry ISRCTN98617255; http://www.isrctn.com/ISRCTN98617255. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1186/s12884-020-03050-3.

Changes in Maternal Heart Rate Variability in Response to the Administration of Routine Obstetric Medication in Hospitalized Patients: Study Protocol for a Cohort Study (MAMA-Heart Study).

Pregnancy is a period of continuous change in the maternal cardiovascular system, partly mediated by the autonomic nervous system. Insufficient autonomic adaptation to increasing gestation is associated with pregnancy complications, such as hypertensive disorders of pregnancy and preterm birth (both major causes of perinatal morbidity and mortality). Consequently, maternal heart rate variability (mHRV), which is a proxy measure for autonomic activity, is increasingly assessed in these cohorts to investigate the pathophysiology of their complications. A better pathophysiological understanding could facilitate the early detection of these complications, which remains challenging. However, such studies (typically performed in pregnancies leading to hospitalization) have generated conflicting findings. A probable reason for these conflicting findings is that these study cohorts were likely administered routine obstetric medications during the study period of which the effects on mHRV are largely unknown. Subsequently, we design a longitudinal, observational study to quantifying the effect of these medications-particularly corticosteroids, which are known to affect fetal HRV-on mHRV to improve the interpretation of past and future studies. We will enroll 61 women admitted to a tertiary obstetric unit with an indication to receive corticosteroids antenatally. Participants' mHRV will be continuously acquired throughout their hospitalization with wrist-worn photoplethysmography to facilitate a within-patient comparison of the effect of corticosteroids on mHRV.

Interprofessional Consensus Regarding Design Requirements for Liquid-Based Perinatal Life Support (PLS) Technology.

Liquid-based perinatal life support (PLS) technology will probably be applied in a first-in-human study within the next decade. Research and development of PLS technology should not only address technical issues, but also consider socio-ethical and legal aspects, its application area, and the corresponding design implications. This paper represents the consensus opinion of a group of healthcare professionals, designers, ethicists, researchers and patient representatives, who have expertise in tertiary obstetric and neonatal care, bio-ethics, experimental perinatal animal models for physiologic research, biomedical modeling, monitoring, and design. The aim of this paper is to provide a framework for research and development of PLS technology. These requirements are considering the possible respective user perspectives, with the aim to co-create a PLS system that facilitates physiological growth and development for extremely preterm born infants.

The effect of intrauterine resuscitation by maternal hyperoxygenation on perinatal and maternal outcome: a randomized controlled trial.

BACKGROUND: Maternal hyperoxygenation is widely used during labor as an intrauterine resuscitation technique. However, robust evidence regarding its beneficial effect and potential side effects is scarce, and previous studies show conflicting results. OBJECTIVE: To assess the effect of maternal hyperoxygenation upon suspected fetal distress during the second stage of term labor on fetal heart rate, neonatal outcome, maternal side effects, and mode of delivery. MATERIALS AND METHODS: In a single-center randomized controlled trial in a tertiary hospital in The Netherlands, participants were randomized in case of an intermediary or abnormal fetal heart rate pattern during the second stage of term labor, to receive either conventional care or 100% oxygen at 10 L/min until delivery. The primary outcome was the change in fetal heart rate pattern. Prespecified secondary outcomes were Apgar score, umbilical cord blood gas analysis, neonatal intensive care unit admission, perinatal death, free oxygen radical activity, maternal side effects, and mode of delivery. We performed subgroup analyses for intermediary and abnormal fetal heart rate, and for small for gestational age fetuses. RESULTS: From March 2016 through April 2018, a total of 117 women were included. Fetal heart rate patterns could be analyzed in 71 women. Changes in fetal heart rate (defined as improvement, equal, or deterioration) in favor of maternal hyperoxygenation were significant (odds ratio, 5.7; 95% confidence interval, 1.7-19.1) using ordinal logistic regression. Apgar score, umbilical cord blood gas analysis, free oxygen radicals, and mode of delivery showed no significant differences between the intervention and control group. Among women with an abnormal fetal heart rate, there were fewer episiotomies on fetal indication in the intervention group (25%) than in the control group (65%, P < .01). CONCLUSION: Maternal hyperoxygenation has a positive effect on the fetal heart rate in the presence of suspected fetal distress during the second stage of labor. There was no significant difference in the mode of delivery or neonatal outcome; however, significantly fewer episiotomies on fetal indication were performed following maternal hyperoxygenation in the subgroup with abnormal fetal heart rate pattern.

Qualitative assessment of interpretability and observer agreement of three uterine monitoring techniques.

OBJECTIVE: The aim of this research was to assess the quality and inter- and intra-observer agreement of tracings obtained by three different techniques for uterine contraction monitoring: the external tocodynamometer (TOCO), the intrauterine pressure catheter (IUPC) and a recently introduced method based on electrohysterography (EHG). STUDY DESIGN: We included 150 uterine activity registrations from a previous prospective observational study (W3 study), conducted at Máxima Medical Centre in Veldhoven, the Netherlands. Term singleton pregnant women were simultaneously monitored with TOCO, IUPC and EHG during labor. Six clinicians, blinded to the source (TOCO, IUPC, or EHG) and subject, evaluated all tracings that were subsequently presented in random order. They annotated contractions and assigned each tracing a score for interpretability of 2 (good), 1 (moderate) or 0 (poor). To evaluate inter-observer agreement, we calculated kappa values for the qualitative assessment, and intraclass correlation coefficients (ICC) for the number of contractions annotated by clinicians. Four clinicians repeated this procedure to evaluate intra-observer agreement. RESULTS: IUPC tracings received the highest quality rating, with a mean score of 1.95, followed by a mean score of 1.60 for EHG and 0.80 for TOCO (p < 0.05). Mean weighted kappa values were 0.63 for TOCO and 0.45 for EHG. The average number of contractions that was picked up by clinicians was 59.8 for the intrauterine pressure catheter, 49.8 for EHG and 26.4 for TOCO. The ICC of the intrauterine pressure catheter was significantly higher than the external methods, regarding both inter- and intra-observer agreement (0.98 and 0.99 respectively). CONCLUSION: IUPC recordings scored best regarding quality, inter- and intra-observer agreement. However, due to safety issues, in many countries this technique is not used anymore. The quality of TOCO was rated as poor and many contractions were missed as compared to the gold standard. From a clinical interpretational point of view, EHG is favorable to TOCO. EHG recordings were assigned higher quality scores, but with less agreement between clinicians. An explanation could be that EHG is a relatively new technique, while IUPC and the TOCO are being used for decades. Building experience with EHG (training) is therefore recommended.

The use of a stronger instructional design by implementing repetitive practice in simulation-based obstetric team training: trainees' satisfaction.

Objective: This study compares satisfaction levels from multiprofessional obstetric care teams about simulation-based obstetric team training courses with and without the instructional design feature repetitive practice. Methods: The present study is part of a multicentre cluster-randomised controlled trial (TOSTI trial) that investigated the effectiveness of a 1 day, multiprofessional, simulation-based obstetric team training. The initial training group received a training which was designed based on best practice. After 1 year, the control group received a training course in which the instructional design was changed by providing repetitive practice. All participants were asked to fill in a 29-item evaluation form with seven questions about baseline characteristics and 22 questions about training features. The questions about training features could be rated on a scale of 1 to 5. Finally, all participants were asked to rate the total training day on a scale of 1-10. Results: The best practice group consisted of 471 trainees and the repetitive practice group of 549, including gynaecologists, residents, midwives and nurses. The best practice group rated the total training day significantly higher than the repetitive practice group (mean 8.8, SD 0.6 and mean 8.7, SD 0.6; p<0.003, Cohen's d=0.19). Several training features were also scored higher in the best practice group. Conclusion: This study showed that obstetric healthcare professionals rated a simulation-based obstetric team training course, with and without repetition of scenarios, both high. The training without the repetitive elements gained higher scores for the total training dayand several, and several training features were scored higher. The difference between the mean scores and the effect sizes for the training features were small. This implies that repetitive practice can be integrated in simulation-based team training to optimise learning effects, with small effects on trainees satisfaction.

Relative versus absolute rises in T/QRS ratio by ST analysis of fetal electrocardiograms in labour: A case-control pilot study.

INTRODUCTION: The additional value of ST analysis during labour is uncertain. In ST analysis, a T/QRS baseline value is calculated from the fetal electrocardiogram and successive T/QRS ratios are compared to this baseline. However, variation in the orientation of the electrical heart axis between fetuses may yield different T/QRS baseline values. In case of a higher T/QRS baseline value more ST events are encountered, although not always related to perinatal outcome. We hypothesised that we can partly correct for this effect by analysing T/QRS rises as a percentage from baseline (relative ST analysis). This study aimed to explore whether relative ST analysis has better diagnostic value for cord acidaemia compared to conventional ST analysis, where predefined fixed T/QRS ratios are used. METHODS AND MATERIALS: A case-control study was performed in 20 term human fetuses during labour; 10 cases (umbilical cord artery pH <7.05 at birth, defining acidaemia) and 10 controls (pH >7.20) were included. The fetal electrocardiogram was recorded using a STAN monitor. We electronically extracted all T/QRS values, baseline and episodic ST events from the STAN monitor and calculated the relative T/QRS changes. The cut-off for relative ST events was determined in a receiver operator characteristic (ROC) curve at optimal specificity for cord acidaemia. Parameters of interest were area under the curve (AUC) of the ROC curve for relative ST events and test performance of both conventional and relative ST analysis. RESULTS: Relative ST analysis showed an AUC of 0.99. The optimal cut-off value for relative T/QRS rise was determined at 0.70. Relative vs conventional (absolute) ST analysis showed a specificity of 100% vs 40% (p = 0.031); sensitivity 90% vs 90%; positive likelihood ratio infinity vs 1.5; negative likelihood ratio 0.10 vs 0.25, respectively. CONCLUSION: Relative ST analysis seems to be a promising method to detect impending fetal acidaemia during labour. Further studies are required to determine the diagnostic accuracy.

Comparison of the psychological and physiological effects on students of a video-assisted or text introduction to a simulated task.

Introduction: The use of different methods for introducing the scenario in simulation-based medical education has not been investigated before and may be a useful element to optimise the effectiveness of learning. The aim of this study was to compare an immersive video-assisted introduction to a minimal text-based one, with regard to emotional assessment of the situation. Methods: In this pilot study, 39 students participated in a medical simulated scenario. The students were randomly assigned to an experimental group (video-assisted introduction) or a control group (minimal textual introduction) and both were followed by performing surgery on LapSim (Surgical Science, Gothenburg, Sweden). The emotional assessment of the situation, cognitive appraisal, was defined as the ratio of the demands placed by an individual's environment (primary appraisal) to that person's resources to meet the demands (secondary appraisal). Secondary outcomes were anxiety (State-Trait Anxiety Inventory), physiological parameters (heart rate, heart rate variability, skin conductance, salivary cortisol), engagement (Game Engagement Questionnaire), motivation (Intrinsic Motivation Inventory) and performance (mean score in percentage calculated by LapSim of predefined levels). Results: Participants in the immersive video group (n=17) were overloaded in terms of their perceived demands (a ratio of 1.17, IQR 0.30) compared with those in the control group (a ratio of 1.00, IQR 0.42, n=22) (P=0.01). No significant differences were found between the groups in secondary outcomes. Both groups showed an increase of anxiety after the introduction method. In the experimental group, this score increased from 9.0 to 11.0, and in the textual group from 7.5 to 10.5, both P<0.01. Discussion: This study shows that the method of introducing a simulated scenario may influence the emotional assessment of the situation. It may be possible to make your simulation introduction too immersive or stimulating, which may interfere with learning. Further research will be necessary to investigate the impact and usefulness of these findings on learning in simulation-based medical education.

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

Following publication of the original article [1], the authors noticed that the sample size for the study group was incorrectly reported in the Methods section.

Uterine Monitoring Techniques from Patients' and Users' Perspectives.

Objective To evaluate preferences from patients and users on 3 uterine monitoring techniques, during labor. Study Design Women in term labor were simultaneously monitored with the intrauterine pressure catheter, the external tocodynamometer, and the electrohysterograph. Postpartum, these women filled out a questionnaire evaluating their preferences and important aspects. Nurses completed a questionnaire evaluating users' preferences. Results Of all 52 participating women, 80.8% preferred the electrohysterograph, 17.3% the intrauterine pressure catheter and 1.9% the external tocodynamometer. For these women, the electrohysterograph scored best regarding application and presence during labor ( p < 0.001). Most important aspects were "least likely to harm" and "least discomfort". Of 57 nurses, 40.4% preferred the electrohysterograph, 35.1% the external tocodynamometer, and 24.6% had no preference, or replied that their preference is subject to situation and patient. Conclusion Patients prefer the electrohysterograph over the external tocodynamometer and the intrauterine pressure catheter, while healthcare providers report ambiguous results.