Characteristics of fetal heart rate tracings prior to uterine rupture

Spontaneous Umbilical Cord Vascular Rupture during Labor: A Retrospective Analysis of 12 Cases

OBJECTIVE

 Umbilical cord vascular rupture is a rare and severe condition that can occur during labor, leading to adverse outcomes for the fetus before as well as after delivery. Prompt diagnosis and intervention are crucial for improving the chances of a successful outcome. We aimed to analyze cases of umbilical cord vascular rupture during labor to provide insights into this challenging condition.

STUDY DESIGN

 This retrospective study evaluated the medical records of patients diagnosed with umbilical cord vessel rupture or umbilical cord hematoma at Fujian Maternity and Child Health Hospital from January 1, 2015, to May 31, 2023. The inclusion criteria included gestational age of ≥28 weeks, occurrence during labor, and availability of complete delivery data. Data on fetal heart rate (FHR) changes, delivery intervals, intraoperative findings, placental pathology, and neonatal outcomes were collected and analyzed.

RESULTS

 A total of 12 cases were analyzed. The incidence of umbilical cord vascular rupture during childbirth was 0.08%. The FHR patterns in umbilical cord rupture during delivery included baseline tachycardia, minimal or absent variability, variable or late deceleration, prolonged deceleration, and undetectable heart rate. The bradycardia-to-delivery interval (BDI) ranged from 6 to 26 minutes. Among the 12 neonates, 9 were discharged well, 2 were stillbirths, and there was 1 neonatal death. Hemorrhagic shock was common in live births.

CONCLUSION

 Our study highlights the significance of continuous FHR monitoring during labor and the urgent need for medical teams to respond quickly in cases of umbilical cord vascular rupture. Despite advancements in neonatal resuscitation techniques, managing cases with undetectable fetal heart activity remains clinically challenging, and even with immediate pregnancy termination, poor neonatal outcomes may still occur.

KEY POINTS

· Umbilical cord vascular rupture during labor is a rare event.. · Its clinical management presents significant challenges.. · Advances in neonatal resuscitation have improved rescue success rates.. · In such cases, hemorrhagic shock is common in live births..

Optimizing the management of acute, prolonged decelerations and fetal bradycardia based on the understanding of fetal pathophysiology

Any acute and profound reduction in fetal oxygenation increases the risk of anaerobic metabolism in the fetal myocardium and, hence, the risk of lactic acidosis. On the contrary, in a gradually evolving hypoxic stress, there is sufficient time to mount a catecholamine-mediated increase in the fetal heart rate to increase the cardiac output and redistribute oxygenated blood to maintain an aerobic metabolism in the fetal central organs. When the hypoxic stress is sudden, profound, and sustained, it is not possible to continue to maintain central organ perfusion by peripheral vasoconstriction and centralization. In case of acute deprivation of oxygen, the immediate chemoreflex response via the vagus nerve helps reduce fetal myocardial workload by a sudden drop of the baseline fetal heart rate. If this drop in the fetal heart rate continues for >2 minutes (American College of Obstetricians and Gynecologists' guideline) or 3 minutes (National Institute for Health and Care Excellence or physiological guideline), it is termed a prolonged deceleration, which occurs because of myocardial hypoxia, after the initial chemoreflex. The revised International Federation of Gynecology and Obstetrics guideline (2015) considers the prolonged deceleration to be a "pathologic" feature after 5 minutes. Acute intrapartum accidents (placental abruption, umbilical cord prolapse, and uterine rupture) should be excluded immediately, and if they are present, an urgent birth should be accomplished. If a reversible cause is found (maternal hypotension, uterine hypertonus or hyperstimulation, and sustained umbilical cord compression), immediate conservative measures (also called intrauterine fetal resuscitation) should be undertaken to reverse the underlying cause. In reversible causes of acute hypoxia, if the fetal heart rate variability is normal before the onset of deceleration, and normal within the first 3 minutes of the prolonged deceleration, then there is an increased likelihood of recovery of the fetal heart rate to its antecedent baseline within 9 minutes with the reversal of the underlying cause of acute and profound reduction in fetal oxygenation. The continuation of the prolonged deceleration for >10 minutes is termed "terminal bradycardia," and this increases the risk of hypoxic-ischemic injury to the deep gray matter of the brain (the thalami and the basal ganglia), predisposing to dyskinetic cerebral palsy. Therefore, any acute fetal hypoxia, which manifests as a prolonged deceleration on the fetal heart rate tracing, should be considered an intrapartum emergency requiring an immediate intervention to optimize perinatal outcome. In uterine hypertonus or hyperstimulation, if the prolonged deceleration persists despite stopping the uterotonic agent, then acute tocolysis is recommended to rapidly restore fetal oxygenation. Regular clinical audit of the management of acute hypoxia, including the "the onset of bradycardia to delivery interval," may help identify organizational and system issues, which may contribute to poor perinatal outcomes.

[Uterine rupture during medical termination of pregnancy or intrauterine death: A risk management study]

OBJECTIVE

To describe and analyze a series of uterine ruptures (UR) that occurred in the context of medical termination of pregnancy (MTP) or intrauterine death (IUD) from a risk management perspective.

METHODS

French retrospective descriptive observational study of all cases of UR occurring during induction for IUD or MTP, reported between 2011 and 2021 by Gynerisq. Cases were recorded on a basis of voluntary reports using targeted questionnaires.

RESULTS

Between November 27, 2011, and August 22, 2021, 12 cases of UR occurring during an induction for IUD or MTP were recorded. 50 % of the patients had never given birth by cesarean section. The term of delivery varied from 17+3 days to 41+2 days. The clinical signs found were pain (n=6), ascending fetal presentation (n=5) and bleeding (n=4). All patients were managed by laparotomy, 5 were transfused. One vascular ligation and one hysterectomy were required.

CONCLUSION

Knowledge of surgical history is involved in the prevention of UR. The signs of detection are pain, ascending presentation and bleeding. The speed of management and good teamwork allow a reduction of maternal complications. The findings of the morbidity and mortality reviews show that prevention and mitigation barriers can be established.

No. 382-Trial of Labour After Caesarean

OBJECTIVE

To provide evidence-based guidelines for the provision of a trial of labour after Caesarean section.

OUTCOMES

Fetal and maternal morbidity and mortality associated with vaginal birth after Caesarean and repeat Caesarean section.

EVIDENCE

MEDLINE database was searched for articles published from January 1, 1995, to October 31, 2017 using the key words "vaginal birth after Caesarean (Cesarean) section." The quality of evidence is described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on the Periodic Health Exam.

VALIDATION

These guidelines were approved by the Clinical Practice Obstetrics Committee and the Board of the Society of Obstetricians and Gynaecologists of Canada.

RECOMMENDATIONS

Tocogram characteristics of uterine rupture: a systematic review

PURPOSE

Timely diagnosing a uterine rupture is challenging. Based on the pathophysiology of complete uterine wall separation, changes in uterine activity are expected. The primary objective is to identify tocogram characteristics associated with uterine rupture during trial of labor after cesarean section. The secondary objective is to compare the external tocodynamometer with intrauterine pressure catheters.

METHODS

MEDLINE, EMBASE, and the Cochrane library were systematically searched for eligible records. Moreover, clinical guidelines were screened. Studies analyzing tocogram characteristics of uterine rupture during trial of labor after cesarean section were appraised and included by two independent reviewers. Due to heterogeneity, a meta-analysis was only feasible for uterine hyperstimulation.

RESULTS

Thirteen studies were included. Three tocogram characteristics were associated with uterine rupture. (1) Hyperstimulation was more frequently observed compared with controls during the delivery (38 versus 21 % and 58 versus 53 %), and in the last 2 h prior to birth (19 versus 4 %). Results of meta-analysis: OR 1.68 (95 % CI 0.97-2.89), p = 0.06. (2) Decrease of uterine activity was observed in 14-40 % and (3) an increasing baseline in 10-20 %. Five studies documented no changes in uterine activity or Montevideo units. A direct comparison between external tocodynamometer and intrauterine pressure catheters was not feasible.

CONCLUSIONS

Uterine rupture can be preceded or accompanied by several types of changes in uterine contractility, including hyperstimulation, reduced number of contractions, and increased or reduced baseline of the uterine tonus. While no typical pattern has been repeatedly reported, close follow-up of uterine contractility is advised and hyperstimulation should be prevented.

Toward a new modality for detecting a uterine rupture: electrohysterogram propagation analysis during trial of labor after cesarean

OBJECTIVE

Observational cohort study which aimed to explore the potential of electrohysterogram (EHG) analysis for detecting a uterine rupture during trial of labor after cesarean. The EHG propagation characteristics surrounding the uterine scar of six patients with a previous cesarean section were compared to a control group of five patients without a scarred uterus.

METHODS

The EHG was recorded during the first stage of labor using a high-resolution 64-channel electrode grid positioned on the maternal abdomen across the cesarean scar. Based on simulations, the inter-channel correlation and propagation direction were adopted as EHG parameters for evaluating possible disruption of electrical propagation by the uterine scar.

RESULTS

No significant differences in inter-channel correlation or propagation direction were observed between the group of patients with an intact uterine scar and the control group. A strong predominance of vertical propagation was observed in one case, in which scar rupture occurred.

CONCLUSIONS

The results support unaffected propagation of electrical activity through the intact uterine scar tissue suggesting that changes in the EHG might only occur in case of rupture.

Posterior uterine rupture secondary to use of herbs leading to peritonitis and maternal death in a primigravida following vaginal delivery of a live baby in western Uganda: a case report

Uterine rupture is a potentially avoidable complication resulting in poor perinatal and maternal outcomes. This case had a number of unusual features including delivery of a healthy live baby; spontaneous posterior uterine rupture in a primigravida (and unscarred uterus); and delayed presentation with signs of peritonitis and sepsis rather than haemorrhage. A 19-year old primigravida had a vaginal delivery of a live infant at term, reporting having taken herbs to induce labour. She deteriorated and was transferred to our unit where she was found to have reduced consciousness, a distended abdomen and signs of sepsis. At laparotomy there was blood-stained ascites, signs of peritonitis and a posterior lower segment uterine rupture. A sub-total hysterectomy was performed but the patient's condition worsened resulting in maternal death 5 days post-operatively. This case highlights a number of differences in the presentation, management and outcomes of uterine rupture in resource-poor compared to resource-rich countries.

Can Intrapartum Cardiotocography Predict Uterine Rupture among Women with Prior Caesarean Delivery?: A Population Based Case-Control Study

OBJECTIVE

To compare cardiotocographic abnormalities recorded during labour in women with prior caesarean delivery (CD) and complete uterine rupture with those recorded in controls with prior CD without uterine rupture.

STUDY DESIGN

Women with complete uterine rupture during labour between 1997 and 2008 were identified in the Danish Medical Birth Registry (n = 181). Cases were validated by review of medical records and 53 cases with prior CD, trial of labour, available cardiotocogram (CTG) and complete uterine rupture were included and compared with 43 controls with prior CD, trial of labour and available CTG. The CTG tracings were assessed by 19 independent experts divided into groups of three different experts for each tracing. The assessors were blinded to group, outcome and clinical data. They analyzed occurrence of defined abnormalities and classified the traces as normal, suspicious, pathological or pre-terminal according to international guidelines (FIGO).

RESULTS

A pathological CTG during the first stage of labour was present in 77% of cases and in 53% of the controls (OR 2.58 [CI: 0.96-6.94] P = 0.066). Fetal tachycardia was more frequent in cases with uterine rupture (OR 2.50 [CI: 1.0-6.26] P = 0.053). Significantly more cases showed more than 10 severe variable decelerations compared with controls (OR 22 [CI: 1.54-314.2] P = 0.022). Uterine tachysystole was not correlated with the presence of uterine rupture.

CONCLUSION

A pathological cardiotocogram should lead to particular attention on threatening uterine rupture but cannot be considered a strong predictor as it is common in all women with trial of labour after caesarean delivery.

Nonreassuring fetal status during trial of labor after cesarean

OBJECTIVE

Concern for uterine rupture has led to the decline in vaginal births after cesarean. Nonreassuring fetal status (NRFS) may precede uterine rupture. The objective of this study was to estimate the risks of uterine rupture, uterine dehiscence, and adverse fetal outcomes associated with NRFS during trial of labor after cesarean (TOLAC).

STUDY DESIGN

In a retrospective cohort study of the previously reported Maternal-Fetal Medicine Units Network prospective cohort cesarean registry, we compared women undergoing repeat cesarean for NRFS after TOLAC to those requiring repeat cesarean for other intrapartum indications. Exclusion criteria included women with a prior cesarean who underwent elective or indicated repeat cesarean or women with a multiple gestation. Primary outcomes included uterine rupture or dehiscence. Secondary outcomes included 5-minute Apgar score <7 and neonatal intensive care unit admission. Planned subanalyses for term and preterm deliveries were performed. Stratified and logistic regression analyses were used.

RESULTS

Of 17,740 women undergoing TOLAC, 4754 (26.8%) had a failed vaginal birth after cesarean. Of those, NRFS was the primary indication for cesarean in 1516 (31.9%). Women with NRFS as the primary indication for repeat cesarean were at increased risk of uterine rupture (adjusted odds ratio, 3.32; 95% confidence interval, 2.21-5.00), uterine dehiscence (adjusted odds ratio, 1.70; 95% confidence interval, 1.09-2.65), 5-minute Apgar score <7, and neonatal intensive care unit admission compared to women with other primary indications.

CONCLUSION

Women attempting TOLAC who require repeat cesarean for NRFS are at increased risk of uterine rupture and uterine dehiscence.

Signs, symptoms and complications of complete and partial uterine ruptures during pregnancy and delivery

OBJECTIVES

Uterine rupture is a rare but potentially catastrophic complication of pregnancy that requires rapid diagnosis. Classically, its signs and symptoms combine pain, fetal heart rate (FHR) abnormalities, and vaginal bleeding. The purpose of this study is to identify these signs and symptoms as well as the immediate complications of complete and incomplete (partial) ruptures of the uterine wall, whether or not they follow a previous cesarean delivery.

STUDY DESIGN

Retrospective study of case records from two university hospital maternity units, from 1987 to 2008.

RESULTS

In a total of 97,028 births during the study period, we identified 52 uterine ruptures (0.05%): 25 complete and 27 partial. Most (89%) occurred in women with a previous cesarean delivery. In complete ruptures, FHR abnormalities were the most frequent sign (82%), while the complete triad of FHR abnormalities-pain-vaginal bleeding was present in only 9%. The signs and symptoms of partial ruptures were very different; these were asymptomatic in half the cases (48%). Neonatal mortality reached 13.6% among the complete ruptures; 27 and 40% of these newborns had pH<6.80 and pH<7.0, respectively. Among the incomplete ruptures, only 7.7% of the newborns had a pH<7.0 and there were no deaths.

CONCLUSION

Although complete rupture of the uterus has a severe neonatal prognosis, the complete set of standard symptoms is present in less than 10% of cases. FHR abnormalities are by far the most frequent sign.

Persistent abdominal pain over uterine scar during labor as a predictor of delivery complications

OBJECTIVE

To evaluate the significance of persistent lower abdominal pain in women with previous cesarean delivery.

METHODS

Various maternal outcomes were compared between women who underwent repeated cesareans owing to persistent lower abdominal pain (study group) and women who underwent repeated cesareans without persistent abdominal pain (control group).

RESULTS

The incidence of uterine rupture was significantly higher in the study group than in the control group (8/81 [9.9%] vs 0/119 [0.0%]; P<0.001). While all women with persistent lower abdominal pain and uterine rupture had an additional sign or symptom, only 6/73 (8.2%) women with persistent abdominal pain without uterine rupture had any additional symptoms (P<0.001). There was no difference in incidence of uterine scar dehiscence between the groups. However, the hospitalization period was significantly longer in the study group (4 vs 3.7days; P<0.05). Trial of labor was a contributing factor to uterine rupture.

CONCLUSION

Isolated persistent lower abdominal pain in women with previous cesarean is a poor indicator of uterine rupture. However, the positive predictive value for uterine rupture is 57% when an additional sign or symptom is present. Dehiscence of the uterine scar is relatively common and it is not associated with persistent abdominal pain.

Identifying risk factors for uterine rupture

Uterine rupture, whether in the setting of a prior uterine incision or in an unscarred uterus, is an obstetric emergency with potentially catastrophic consequences for both mother and child. Numerous studies have been published regarding various risk factors associated with uterine rupture. Despite the mounting data regarding both antepartum and intrapartum factors, it currently is impossible to predict in whom a uterine rupture will occur. This article reviews the data regarding these antepartum and intrapartum predictors for uterine rupture. The author hopes that the information presented in this article will help clinicians assess an individual's risk for uterine rupture.

Essai de travail en cas de césarienne antérieure

OBJECTIVE

The aim of this review was to relate the evolution of obstetrical management of delivery in women who had previously undergone cesarean delivery and to search the studies supporting the choice of the mode of delivery.

MATERIAL AND METHOD

We identified relevant studies through a computer search in the Medline database.

RESULTS

After a period from 1980 to 2000 when the vaginal delivery had been increasingly recommended, a growth in the use of the planned cesarean delivery was observed. Recent studies report more evidence that uterine rupture is the result of trial of labor and that adverse perinatal outcomes are associated with uterine rupture. The risk of uterine rupture is increased with labor induction. The use of prostaglandins appears to be implicated in a significant increase of uterine rupture, and subsequently might be contraindicated in this situation. The use of oxytocin induced labor appears to increase the risk of uterine rupture. However, the level of adverse perinatal outcomes is low. The choice of the mode of delivery should take into account the likelihood of a further pregnancy, due to the increased risk of placental pathologic conditions depending on the number of repeated cesarean sections.

CONCLUSION

An optimal decision for the mode of delivery should be shared with the pregnant women and all these factors should be taken into consideration.

WHO systematic review of maternal mortality and morbidity: the prevalence of uterine rupture

OBJECTIVE

To determine the prevalence of uterine rupture worldwide.

DESIGN

Systematic review of all available data since 1990.

SETTING

Community-based and facility-based reports from urban and rural studies worldwide. Sample Eighty-three reports of uterine rupture rates are included in the systematic review. Most are facility based using cross-sectional study designs.

METHODS

Following a pre-defined protocol an extensive search was conducted of 10 electronic databases as well as other sources. Articles were evaluated according to specified inclusion criteria. Uterine rupture data were collected along with information on the quality of reporting including definitions and identification of cases. Data were entered into a database and tabulated using SAS software.

MAIN OUTCOME MEASURES

Prevalence of uterine rupture by country, period, study design, setting, participants, facility type and data source.

RESULTS

Prevalence figures for uterine rupture were available for 86 groups of women. For unselected pregnant women, the prevalence of uterine rupture reported was considerably lower for community-based (median 0.053, range 0.016-0.30%) than for facility-based studies (0.31, 0.012-2.9%). The prevalence tended to be lower for countries defined by the United Nations as developed than the less or least developed countries. For women with previous caesarean section, the prevalence of uterine rupture reported was in the region of 1%. Only one report gave a prevalence for women without previous caesarean section, from a developed country, and this was extremely low (0.006%).

CONCLUSION

In less and least developed countries, uterine rupture is more prevalent than in developed countries. In developed countries most uterine ruptures follow caesarean section. Future research on the prevalence of uterine rupture should differentiate between uterine rupture with and without previous caesarean section.

Fetal Heart Rate Changes Associated With Uterine Rupture

OBJECTIVE

To identify fetal heart rate characteristics of patients with uterine rupture compared with successful vaginal birth after cesarean (VBAC) controls.

METHODS

This is a case-control study. Obstetric records of patients at the University of Washington Medical Center and Swedish Medical Center were reviewed for cases of uterine rupture. Entry criteria included operative confirmation of the diagnosis, gestational age beyond 24 weeks, presence of one or more prior low transverse uterine incisions, and availability of fetal heart tracings. Each case was matched with 3 controls randomly selected from a pool of successful VBAC deliveries at the same institution within 1 year. Three blinded independent examiners then examined fetal heart tracings. Each tracing was rated for the presence of fetal tachycardia, mild or moderate variable decelerations, severe variable decelerations, late decelerations, prolonged decelerations, fetal bradycardia, and loss of uterine tone in both the first and second stages of labor separately.

RESULTS

Of the 48 uterine ruptures identified, 36 met inclusion criteria. These were matched with 100 controls. Cases showed significantly increased rates of fetal bradycardia than controls in the first stage (P <.01) and second stage (P <.01). No significant differences were noted in rates of mild or severe variable decelerations, late decelerations, prolonged decelerations, fetal tachycardia, or loss of uterine tone.

CONCLUSION

Fetal bradycardia in the first and second stage is the only finding to differentiate uterine ruptures from successful VBAC patients.

LEVEL OF EVIDENCE

II-2

A Case Report: Change in Fetal Heart Rate Pattern on Spontaneous Uterine Rupture at 35 Weeks Gestation after Laparoscopically Assisted Myomectomy

A 31-year-old nulligravid woman who underwent laparoscopically assisted myomectomy 5 months before becoming pregnant suffered uterine rupture at 35 weeks gestation. A 50 g intramuscular myomatous node had been removed laparoscopically. Early signs of rupture included sudden onset of severe abdominal tenderness and frequent uterine contractions despite reassuring FHR tracing. Variable deceleration was observed as late as 7.5 hours after onset. Emergency cesarean section was performed due to increasing severity of tenderness, revealing complete uterine rupture at the fundus site without extrusion of the fetus or placenta. A male neonate (2,860 g) was delivered without asphyxia and an Apgar score of 8. Total volume of hemorrhage was approximately 50 ml. The ruptured uterine wall was repaired by suturing in 2 layers. The present case indicates that sudden onset of abdominal tenderness in pregnant women with a history of laparoscopic myomectomy may suggest uterine rupture even in the presence of reassuring FHR. This is a rare case, as non-reassuring FHR patterns generally appear in the late stages of uterine rupture.

Uterine rupture during VBAC trial of labor: risk factors and fetal response

For the woman with a prior uterine scar, neither repeat elective cesarean birth nor vaginal birth after cesarean birth (VBAC) trial of labor (TOL) is risk-free. When VBAC-TOL is successful, it is associated with less morbidity than repeat cesarean birth. However, when VBAC-TOL fails due to uterine rupture, severe consequences often ensue. The challenge for clinicians today is to provide women who desire TOL after cesarean birth, a more individualized risk assessment of uterine rupture, thereby enhancing success and optimizing outcome. This article examines major risk factors for uterine rupture during VBAC-TOL. In addition, fetal response to uterine rupture and neonatal outcomes are reviewed.