Uterine contractile activity and neonatal outcome - A blind analysis of a randomized controlled trial cohort.

INTRODUCTION: Sufficient contractions are necessary for a successful delivery but each contraction temporarily constricts the oxygenated blood flow to the fetus. Individual fetal or placental characteristics determine how the fetus can withstand this temporary low oxygen saturation. However, only a few studies have examined the impact of uterine activity on neonatal outcome and even less attention has been paid to parturients' individual characteristics. Our objective was therefore to find out whether fetuses compromised by maternal or intrapartum risk factors are more vulnerable to excessive uterine activity. MATERIAL AND METHODS: Uterine contractile activity was assessed by intrauterine pressure catheters. Women (n = 625) with term singleton pregnancies and fetus in cephalic presentation were included in this secondary, blind analysis of a randomized controlled trial cohort. Intrauterine pressure as Montevideo units (MVU), contraction frequency/10 min and uterine baseline tone were calculated for 4 h prior to birth or the decision to perform cesarean section. Uterine activity in relation to umbilical artery pH linearly or ≤7.10 was used as the primary outcome. Need for operative delivery (either cesarean section or vacuum-assisted delivery) due to fetal distress was analyzed as a secondary outcome. In addition, belonging to vulnerable subgroups with, for example, chorioamnionitis, hypertensive or diabetic disorders, maternal smoking or neonatal birthweight <10th percentile were investigated as additional risk factors. RESULTS: A linear decline in umbilical artery pH was seen with increasing intrauterine pressure in all deliveries (p < 0.001). Among parturients with suspected chorioamnionitis, every increasing 10 MVUs increased the likelihood of umbilical artery pH ≤7.10 (odds ratio [OR] 1.17, 95% confidence interval [CI] 1.02-1.34, p = 0.023). The need for operative delivery due to fetal distress was increased among all laboring women by every increasing 10 MVUs (OR 1.05, 95% CI 1.01-1.09, p = 0.015). This association with operative deliveries was further increased among parturients with hypertensive disorders (OR 1.23, 95% CI 1.05-1.43, p = 0.009) and among those with diabetic disorders (OR 1.13, 95% CI 1.04-1.28, p = 0.003). CONCLUSIONS: Increasing intrauterine pressure impairs umbilical artery pH especially among parturients with suspected chorioamnionitis. Fetuses in pregnancies affected by chorioamnionitis, hypertensive or diabetic disorders are more vulnerable to high intrauterine pressure.

A rare case of massive intrapartum hemorrhage followed by inner myometrial laceration during a vaginal delivery: A case report.

Key Clinical Message: Considering the laceration of the inner layer of the myometrium as an important and controllable cause of bleeding during childbirth can lead to saving the mother's life. Abstract: Laceration of the inner layer of the myometrium can cause massive bleeding during and after childbirth, which can lead to the death of the mother if it is not diagnosed in time.we presented a rare case of massive intrapartum bleeding following myometrial laceration that diagnosed correctly and the patient survived with in-time treatments. The patient was a 26-year-old woman who was under observation for term pregnancy and complaint of rupture of membranes (ROM) and vaginal bleeding. Following the spontaneous course of labor and without receiving oxytocin, during the normal course of labor, she was with an estimated total blood loss of 750 mL bleeding, which despite the normal fetal heart rate and with the mother's indication for cesarean section, was transferred to the operating room and underwent cesarean section. During the cesarean section, the amniotic fluid was clear, after the removal of the placenta, severe and clear bleeding was flowing from the posterior wall of the uterus, which was caused by the laceration of the inner layer of the myometrium in the posterior wall of the lower segment of the uterus. The myometrial laceration was repaired with absorbable continuous locked sutures and hemostasis was established, and then the patient used uterotonic drugs, and after monitoring, the patient was discharged from the hospital in good condition.

Application of a Negative Intrauterine Pressure Suction Device for Prophylactic Management of Atonic Postpartum Hemorrhage: A Quality Improvement Study.

BACKGROUND: Postpartum hemorrhage (PPH) is the leading cause of maternal mortality worldwide. PPH-preventing interventions need to be prioritized and can be integrated with conventional methods of PPH prevention. The introduction of negative intrauterine pressure using a suction cannula can be one of the cheapest modalities to decrease PPH secondary to uterine atonicity. This method has brought a renaissance to practical obstetrics in low-middle income countries (LMIC), where the cost and availability of uterotonics are major health issues. METHODS: It was a prospective quality improvement (QI) study conducted in the labor and delivery wards of a tertiary care medical institute and teaching center over the duration of one year. We aimed to assess the decrease in the incidence of atonic PPH with a negative intrauterine pressure suction device (NIPSD) integrated with active management of the third stage of labor (AMTSL) in the prevention of atonic PPH following normal vaginal delivery in low-risk antenatal women. In the initial six months, routine AMTSL was instituted for all consenting women (group 1). In the next six months, NIPSD was integrated with AMTSL (group 2). Data pertaining to the amount of blood loss, the incidence of primary PPH, uterine tone, fall in hemoglobin and hematocrit levels post-delivery, need for blood transfusion, and doctor and patient satisfaction were tabulated for all patients. RESULTS: A total of 1324 consenting women were eligible for enrollment during the study time frame. In the initial six months (baseline period, group 1), 715 participants were subjected to routine AMTSL in the third stage of labor. During the intervention phase (group 2), 609 parturient women were recruited. There was no significant difference in baseline parameters between the two groups. With the introduction of NIPSD to routine AMTSL, there was a significant decrease in the average volume of blood loss during vaginal delivery (group 1 = 389.45+65.42 ml, group 2 = 216.66+34.27 ml; p-value = 0.012). The incidence of atonic PPH was reduced by more than 75% (group 1 = 13 women, group 2 = 3 women; p-value = 0.001) after the introduction of NIPSD complementing routine AMTSL. The introduction of NIPSD has also been instrumental in reducing the cost burden on patient and hospital expenditures. The net benefit of its introduction resulted in a reduction of the overall cost burden of blood transfusions by around 70%. CONCLUSION: PPH is a public health problem, and measures to reduce PPH must be implemented to decrease this health burden. In countries with low resources, complementing routine AMTSL with NIPSD can be instrumental in decreasing the incidence of PPH. Considering its cost-effectiveness and reusability, LMIC can adopt NIPSD as a routine measure in all vaginal deliveries.

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.

Experiences with intrapartum fetal monitoring in the Netherlands: A survey study.

INTRODUCTION: Worldwide, cardiotocography is used for continuous monitoring of fetal heart rate (FHR) and uterine contractions during labour. Different methods for FHR registration and registration of contractions are available. Literature about the frequency of use of different fetal monitoring methods is lacking. OBJECTIVE: To evaluate the use of and preferences for fetal monitoring methods for intrapartum fetal monitoring among Dutch obstetric care providers. STUDY DESIGN: Between October and November 2020 the Dutch Society of Obstetrics and Gynaecology sent an email invitation to all secondary care midwives and gynaecologists (in training) in the Netherlands to complete an online survey regarding the use and personal experience with fetal monitoring methods. The survey mainly consisted of multiple choice questions. Descriptive statistics are reported. Continuous variables were presented as median with interquartile ranges (IQR). Categorical variables were expressed as numbers with percentages. RESULTS: The response rate was 29 % (n/N = 510/1748). All Dutch hospitals were represented. The respondents estimated the use of fetal scalp electrode (FSE) at 71 % (IQR 58-85 %) of deliveries. The most common indication for use of the FSE was inadequate external FHR registration (94 %). More than half (54 %) of the respondents reported to use intrauterine pressure catheter with an estimated use of 5 % (IQR 2-8 %) of deliveries. The most common indication for use of intrauterine pressure catheter was inadequate external contraction registration (75 %). The use of ST-analysis was reported in 25 % of the respondents with an estimated use of 60 % (IQR 30-72 %) of deliveries. Almost all respondents (99 %) reported to use fetal blood sampling with an estimated use of 15 % (IQR 10-23 %) of deliveries. Ninety percent of respondents would prefer a valid and reliable external monitoring technique during labour. Thirty-one percent of respondents assume that external fetal monitoring with non-invasive fetal electrocardiography and electrohysterography will become standard care within the next 5 years. CONCLUSIONS: Currently, the FSE is the most used technique for FHR monitoring during labour in the Netherlands. The most common indication for use of FSE is inadequate external FHR registration. Obstetric care providers would prefer a non-invasive external registration method that provides reliable data.

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.

How does uterine contractile activity affect the success of trial of labour after caesarean section, and the risk of uterine rupture? An exploratory, blinded analysis of a cohort from a randomised controlled trial.

OBJECTIVE: To investigate the impact of uterine contractile activity on the outcome of trial of labour after caesarean section (TOLAC). DESIGN: Secondary, blinded analyses of a prospective TOLAC cohort. SETTING: Two labour wards, one in a university tertiary hospital and the other in a central hospital. POPULATION: A total of 194 TOLAC parturients with intrauterine tocodynamometry during labour. METHODS: Analysis of intrauterine pressure, frequency of contractions and baseline tonus of uterine muscle in 30-minute periods for 4 hours before birth. MAIN OUTCOME MEASURES: Primary outcome: uterine contractile activity during TOLAC. Secondary aims: contributors associated with failed TOLAC and uterine rupture. RESULTS: TOLAC succeeded in 74% of cases. Uterine contractile activity, expressed as intrauterine pressure, was significantly higher in successful TOLAC compared with failed TOLAC (210 versus 170 Montevideo units). The statistically significant risk factors of failed TOLAC, after multivariate regression analysis, were prolonged gestational age, reduced cervical dilatation at admission and lower mean intrauterine pressure. In cases of uterine rupture, contractile activity did not differ from that in failed TOLAC. Cervical ripening with a Foley catheter appeared to be a risk factor for uterine rupture, as well as cervical dilatation <3 cm at admission. The incidence of total uterine rupture was 2.6% (n = 5). CONCLUSIONS: Women with successful vaginal birth had higher uterine contractile activity than those experiencing failed TOLAC or uterine rupture despite similar use of oxytocin. Induction of labour with a Foley catheter turned out to be a risk factor for uterine rupture during TOLAC among parturients with no previous vaginal delivery. TWEETABLE ABSTRACT: During VBAC the response to oxytocin, assessed as intrauterine pressure, is greater and adequate, in contrast to failed TOLAC.

Intrauterine contraction parameters at baseline and following epidural and combined spinal-epidural analgesia: A repeated measures comparison.

OBJECTIVE: The effects of epidural and combined spinal-epidural analgesia on uterine contraction parameters are unclear, although as many as 80% of laboring women use neuraxial analgesia. We explored the effects of epidural and combined spinal-epidural analgesia on all uterine contraction parameters using a retrospective analysis of selected parturients, who required Intrauterine Pressure Catheter (IUPC) instrumentation for clinical management. Additionally, we analyzed the effects of parity, Pitocin dose, and mode of neuraxial anesthesia, i.e. epidural verses combined spinal-epidural on uterine contractility. DESIGN: Using a retrospective within and between repeated measure design we compared uterine contraction parameters at 4 time points (epochs): (1) baseline, (2) pre-epidural fluid bolus, (3) immediate and (4) secondary post-epidural/combined spinal-epidural analgesia to detect differences in contractility over time comparing two types of epidural interventions. METHODS: Eighteen healthy parturients at term gestation were admitted to the labor unit for induction, augmentation, or spontaneous labor. Contraction parameters including frequency, duration, peak intensity, resting intensity and duration, and Montevideo Units (MVUs) were collected using fetal monitor strip data with intrauterine pressure catheter (IUPC) instrumentation. FINDINGS: Parametric and non-parametric tests showed no significant differences within or between the two Epidural intervention groups for frequency, duration, peak intensity, resting intensity and duration, and MVUs at all epochs at the .05 alpha level. Compared with Nulliparous women, multiparous women had significantly lower contraction intensity and longer contraction duration. Based on multilevel modeling (MLM), neither Pitocin dose nor type of epidural intervention revealed significant differences on any contraction parameters. CONCLUSIONS: When parity, other demographic variables and Pitocin dose were statistically controlled, no uterine contraction parameter changed from baseline through 90 min following either epidural or combined spinal-epidural analgesia. Obstetrical care providers should consider the preciseness their contraction monitoring instrumentation and their clinical management preferences as well parity as before prescribing Pitocin after neuraxial analgesia intervention.

Evidence-based labor management: first stage of labor (part 3).

There are several interventions during the first stage of labor that have been studied. Vaginal disinfection with chlorhexidine cannot be recommended. Intrapartum antibiotic prophylaxis is recommended for group B streptococcus-positive women. Antibiotic therapy can be considered in women with term prelabor rupture of membranes whose latency is expected to be >12 hours. Aromatherapy with essential oils through inhalation or back massage can be considered. Immersion in water can be considered. Oral restriction of fluid or solid food is not recommended. In the setting of oral restriction, intravenous fluid containing dextrose at a rate of 250 mL/h is recommended. Upright positions and ambulation are recommended in women without regional anesthesia, and women with regional anesthesia can adopt whatever position they find most comfortable and choose to ambulate or not ambulate. Continuous bladder catheterization cannot be recommended. There is no recommended frequency of cervical examinations or sweeping of membranes. The use of a partogram cannot be recommended as a routine intervention. Routine use of the peanut ball cannot be recommended. Antispasmodic agents cannot be recommended. Routine amniotomy alone in normally progressing spontaneous first stage of labor cannot be recommended. Oxytocin augmentation is recommended to shorten the time to delivery for women making slow progress in spontaneous labor, and higher doses of oxytocin can be considered. Early intervention with oxytocin and amniotomy for the prevention and treatment of dysfunctional or slow labor is recommended. Routine use of intrauterine pressure catheter and ultrasound cannot be recommended. Cesarean delivery for arrest should not be performed unless labor has arrested for a minimum of 4 hours with adequate uterine activity or 6 hours with inadequate uterine activity in a woman with rupture of membranes, adequate oxytocin, and ≥6 cm cervical dilation.

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.

Critical analysis of electrohysterographic methods for continuous monitoring of intrauterine pressure.

Monitoring the progression of uterine activity provides important prognostic information during pregnancy and delivery. Currently, uterine activity monitoring relies on direct or indirect mechanical measurements of intrauterine pressure (IUP), which are unsuitable for continuous long-term observation. The electrohysterogram (EHG) provides a non-invasive alternative to the existing methods and is suitable for long-term ambulatory use. Several published state-of-the-art methods for EHG-based IUP estimation are here discussed, analyzed, optimized, and compared. By means of parameter space exploration, key parameters of the methods are evaluated for their relevance and optimal values. We have optimized all methods towards higher IUP estimation accuracy and lower computational complexity. Their accuracy was compared with the gold standard accuracy of internally measured IUP. Their computational complexity was compared based on the required number of multiplications per second (MPS). Significant reductions in computational complexity have been obtained for all published algorithms, while improving IUP estimation accuracy. A correlation coefficient of 0.72 can be obtained using fewer than 120 MPS. We conclude that long-term ambulatory monitoring of uterine activity is possible using EHG-based methods. Furthermore, the choice of a base method for IUP estimation is less important than the correct selection of electrode positions, filter parameters, and postprocessing methods. The presented review of state-of-the-art methods and applied optimizations show that long-term ambulatory IUP monitoring is feasible using EHG measurements.

Amniodrainage-Induced Circulatory Dysfunction in Women Treated for Twin-To-Twin Transfusion Syndrome.

Twin-to-twin transfusion syndrome (TTTS) in monochorionic-diamniotic twin pregnancies usually requires fetoscopic laser ablation (FLA) followed by amniodrainage (AD). Perioperative maternal hemodynamic changes and hemodilution have been observed. Little is known about the underlying pathophysiology. We aimed to evaluate the impact of high volume amniodrainage on intrauterine pressure, placental thickness and maternal blood characteristics. A total of 18 cases of TTTS were included in this prospective pilot study. All patients were treated with FLA and subsequent AD. Intrauterine pressure and placental thickness were assessed before, during and after amniodrainage. Maternal hemoglobin, hematocrit and serum albumin were measured at admission and 24 h after the intervention. Amniodrainage led to a decrease in mean intrauterine pressure (from 30.1 ± 8.1 mmHg to 17.6 ± 3.6 mmHg (p < 0.001)) and an increase in mean placental thickness (from 16.8 ± 6.4 mm to 31.83 ± 8.64 mm (p < 0.001)). There was a positive correlation between changes in placental thickness and the amount of amniodrainage during intervention (Pearson's Rho 0.73; p = 0.001). Hematocrit decreased from 33.4 ± 3.8 (%) to 28.4 ± 3.5 (%), i.e., an increase in relative blood volume by 18 ± 10.2% (p < 0.001). Albumin decreased from 37.9 ± 0.9 g/L to 30.7 ± 2.2 g/L, i.e., an increase in relative plasma volume by 24 ± 8.1% (p < 0.001). Amniodrainage leads to uterine decompression, increased placental thickness and subsequent maternal hemodilution. We propose the term "amniodrainage-induced circulatory dysfunction" for these specific maternal hemodynamic changes in the treatment of twin-to-twin transfusion syndrome.

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.

Evaluation of electrohysterogram measured from different gestational weeks for recognizing preterm delivery: a preliminary study using random Forest.

Developing a computational method for recognizing preterm delivery is important for timely diagnosis and treatment of preterm delivery. The main aim of this study was to evaluate electrohysterogram (EHG) signals recorded at different gestational weeks for recognizing the preterm delivery using random forest (RF). EHG signals from 300 pregnant women were divided into two groups depending on when the signals were recorded: i) preterm and term delivery with EHG recorded before the 26th week of gestation (denoted by PE and TE group), and ii) preterm and term delivery with EHG recorded during or after the 26th week of gestation (denoted by PL and TL group). 31 linear features and nonlinear features were derived from each EHG signal, and then compared comprehensively within PE and TE group, and PL and TL group. After employing the adaptive synthetic sampling approach and six-fold cross-validation, the accuracy (ACC), sensitivity, specificity and area under the curve (AUC) were applied to evaluate RF classification. For PL and TL group, RF achieved the ACC of 0.93, sensitivity of 0.89, specificity of 0.97, and AUC of 0.80. Similarly, their corresponding values were 0.92, 0.88, 0.96 and 0.88 for PE and TE group, indicating that RF could be used to recognize preterm delivery effectively with EHG signals recorded before the 26th week of gestation.

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.

Role of the serotonergic pathway in uterotonic activity of Ananas comosus (L.) Merr. - An in vitro and in vivo study.

BACKGROUND: Ananas comosus (L.) Merr. has been used as a traditional medicine in inducing abortion in many countries. Our previous in vitro experiments showed that the aqueous fraction (F4) of A. comosus extract stimulated the rat and human uterine contractions. PURPOSE: The aim of this study was to identify the bioactive compound and further investigate the molecular mechanism of F4 induced contraction and the in vivo uterotonic effect of F4. MATERIALS AND METHODS: Organ bath studies were employed to compare the stimulatory effect of F4 in non and late pregnant uterine tissue followed by isolation of protein from late pregnant uterine tissue for the western blot analysis. The PhysioTel transmitter was implanted in pregnant SD rats to measure the changes in intrauterine pressure (IUP). Analyses of the crude extract and active principle in F4 was performed using LC-HRMS. RESULTS: Ripe F4 in a similar manner as serotonin produced a greater stimulatory response in late pregnant than non-pregnant uterine tissue without significant change in potency; ripe F4 also increased ERK phosphorylation which eventually led to a significant increase of the final product, MMP-13. In pregnant rats (E18), oral ripe F4 (1.5 g.100 g-1 body weight) and ergometrine (1 mg) did not stimulate the uterine contraction probably due to the low level of estradiol and as a consequence low 5-HT receptors at the time of administration. In contrast, in postpartum rats, oral administration of F4 and ergometrine produced a significant increase in maximal IUP to 4.3 and 4.9 folds of basal IUP respectively. Contrary to the folklore use, unripe F4 did not stimulate the uterine activity during pregnancy and postpartum. Bioassay guided fractionation identified serotonin as a major bioactive compound in ripe F4. CONCLUSIONS: Our data clearly indicate that the uterotonic effect of ripe F4 is mediated via the serotonergic pathway and suggest that serotonin rich diet may increase the peripheral serotonin and implicate in diverse physiological functions, including uterine motility.

Rescue of the fetal damage associated with high intrauterine pressure by 17ß-estradiol injection in ovariectomized progesterone-treated pregnant mice.

The present study examined the effects of progesterone (P) and 17ß-estradiol (E2) on fetal damage and intrauterine pressure in ovariectomized pregnant mice. The mice were ovariectomized on gestational day (GD) 9 (copulation plug = GD 0), and daily subcutaneous injection of various doses of P (2, 3 or 4 mg) or 4 mg P plus E2 (0.05 or 0.1 µg) was given thereafter. Although P alone increased percentage of normal fetuses on GD 17 dose-dependently, fetal injury with edematous hematomata on their extremities was frequently observed. In the group treated with 4 mg P, the injured fetus was found at the highest percentage (18%) and intrauterine pressure was significantly higher than that in intact pregnant mice (controls). No injured fetus on GD 17 was found by the treatment with 4 mg P plus 0.05 or 0.1 µg E2, and the treatments decreased the intrauterine pressure to the level of controls. Percentage of normal fetuses in the ovariectomized mice treated with 4 mg P plus 0.05 µg E2 was similar to that of controls, while that in the ovariectomized mice treated with 4 mg P plus 0.1 µg E2 markedly decreased. The results suggest that estrogen decreases intrauterine pressure to defend fetal damage in ovariectomized P-treated mice, and a high estrogen level interrupted pregnancy while keeping this estrogen action.

Clinical assessment of uterine contractions.

The assessment of uterine contractions is important in clinical decision-making, but the precise role for appraising contractions remains controversial. Four clinical approaches to assessing contractions are available: manual palpation; intrauterine pressure determination; external tocodynamometry; and electrohysterography. Palpation is inexpensive and harmless but requires the constant bedside presence of a trained observer. Intrauterine pressure measurement is considered the most sensitive and specific technique, and has become the standard by which other methods are judged; however, its quantitative measurements are not always precise or reproducible. Moreover, the availability of intrauterine pressure measurements does not seem to improve maternal or neonatal outcomes in most situations. External tocodynamometry is the most widely used technique. It is easy to apply and provides reasonably accurate information about the frequency and duration of contractions, but not their amplitude. It can require frequent adjustment during labor and might not work well in patients who are obese. Electrohysterography is a recently available noninvasive technology that detects uterine electrical activity using electrodes placed on the mother's abdominal wall. This approach is at least as reliable and accurate as tocodynamometry.

Pressure dynamics in the non-gravid uterus: intrauterine pressure cannot confirm tubal occlusion after non-surgical permanent contraception.

OBJECTIVE: The objective was to determine if intrauterine pressure can distinguish bilateral tubal occlusion (BTO) from unilateral or bilateral tubal patency (TP) in women following a permanent contraception procedure. STUDY DESIGN: We used a small inline pressure sensor to continuously monitor intrauterine pressure during hysterosalpingogram (HSG) in a cross-sectional study that enrolled women having HSGs for any indication. The primary outcome was the peak intrauterine pressure compared between women with BTO and TP as verified by HSG. RESULTS: We enrolled 150 subjects, of which 111 (74.0%) provided usable pressure readings. Of these, 98/111 (88.3%) had TP, and 13 (11.7%) had BTO. There was no difference in peak intrauterine pressure for subjects with TP (mean 293.8±58.7 mmHg) compared to those with BTO (292.7±71.3 mmHg, p=.95). Among parous women, peak intrauterine pressure in subjects with BTO (311.9±78.0 mmHg) was higher but not significantly different from subjects with TP (282.7±49.2 mmHg, p=.20). In linear regression analysis, peak intrauterine pressure was not associated with age, body mass index, gravidity or having at least one prior live birth. CONCLUSIONS: Measurement of peak intrauterine pressure does not distinguish between women with patent and blocked fallopian tubes. This approach would not be clinically useful to verify occlusion following permanent contraception. IMPLICATIONS: Peak intrauterine pressure does not differ between women with patent and occluded fallopian tubes and cannot be used to confirm tubal occlusion after nonsurgical permanent contraception.