Amniotic fluid embolism: 20-year incidence and case-fatality trends in the United States.

OBJECTIVE: To estimate incidence and case-fatality rates of amniotic fluid embolism (AFE) and to examine their temporal trends. STUDY DESIGN: Population-based retrospective cohort study using the 2000-2019 Health Care Cost and Utilization Project, Nationwide Inpatient Sample (HCUP-NIS). Annual population rates were estimated using HCUP-NIS specific weighting. Descriptive analyses and logistic regression described trends within the cohort. RESULTS: Over the study period, AFE incidence rate remained stable (mean 4.9 cases/100,000 deliveries) and the case-fatality rate declined (mean 17.7 %,95 % CI 16.40-10.09). Highest AFE incidence rates and fatality rates were in women ≥ 35 years, African-Americans, and in urban-teaching hospitals. AFE mortality rates decreased among Hispanics. CONCLUSION: AFE rates remained stable and fatality rates declined over time. Highest rates of AFE occurrence and death were in women who typically have greater risk of experiencing adverse obstetrical outcomes. Continued research into early diagnostic methods and effective treatments are needed to further improve AFE incidence and mortality rates.

Placental mesenchymal dysplasia complicated with sudden fetal demise and amniotic fluid embolism: a case report.

BACKGROUND: Placenta mesenchymal dysplasia (PMD) is a rare placental anomaly associated with various fetal and maternal complications. Whether close ultrasound surveillance can prevent intrauterine fetal demise (IUFD) in patients with PMD is still under investigation. Amniotic fluid embolism (AFE) is a rare, lethal, and unpredictable maternal complication that has never been described in association with PMD. Here, we report a case of PMD, in which the fetus eventually demised in utero despite weekly color Doppler monitoring, and the mother subsequently encountered AFE during delivery. CASE PRESENTATION: A 43-year-old woman who had received three frozen embryo transfer, was found to have a singleton pregnancy with an enlarged multi-cystic placenta at 8 weeks' gestation. Fetal growth restriction (FGR) was noted since the 21stweek. The fetus eventually demised in-utero at 25 weeks despite weekly color Doppler surveillance. Cesarean section was performed under general anesthesia due to placenta previa totalis and antepartum hemorrhage. During surgery, the patient experienced a sudden blood pressure drop and desaturation followed by profound coagulopathy. AFE was suspected. After administration of inotropic agents and massive blood transfusion, the patient eventually survived AFE. PMD was confirmed after pathological examination of the placenta. CONCLUSIONS: While FGR can be monitored by color Doppler, our case echoed previous reports that IUFD may be unpreventable even under intensive surveillance in PMD cases. Although AFE is usually considered unpredictable, PMD can result in cumulative risk factors contributing to AFE. Whether a specific link exists between the pathophysiology of PMD and AFE requires further investigation.

Association of Pregnancy Characteristics and Maternal Mortality With Amniotic Fluid Embolism.

Importance: Amniotic fluid embolism (AFE) is an uncommon pregnancy complication but is associated with high maternal mortality. Because of the rarity of AFE, associated risks factors and maternal outcomes have been relatively understudied. Objective: To examine the clinical, pregnancy, and delivery characteristics and the maternal outcomes related to AFE in a recent period in the US. Design, Setting, and Participants: This retrospective cohort study examined hospital deliveries from January 1, 2016, to December 31, 2019, from the Healthcare Cost and Utilization Project's National Inpatient Sample. Main Outcomes and Measures: The primary outcome was clinical, pregnancy, and delivery characteristics of AFE, assessed with a multivariable binary logistic regression model. The coprimary outcome was failure to rescue, defined as maternal mortality after AFE. Associations with other severe maternal morbidity indicators and failure to rescue per clinical and pregnancy characteristics were also assessed. Results: A total of 14 684 135 deliveries were examined, with AFE diagnosed in 880 women, corresponding to an incidence rate of 6.0 per 100 000 deliveries. The cohort-level median patient age was 29 years (IQR, 25-33 years). In a multivariable analysis, (1) patient factors of older age, Asian and Black race, Western US region, pregestational hypertension, asthma, illicit substance use, and grand multiparity; (2) pregnancy factors of placental accreta spectrum (PAS), placental abruption, uterine rupture, polyhydramnios, chorioamnionitis, preeclampsia, fetal growth restriction, and fetal demise; and (3) delivery factors of early gestational age, cervical ripening, cesarean delivery, operative delivery, and manual removal were associated with AFE. Among these characteristics, PAS had the largest association with AFE (adjusted odds ratio [aOR], 10.01; 95% CI, 7.03-14.24). When stratified by the PAS subtypes, more severe forms of PAS had a greater association with AFE (aOR for increta and percreta, 17.35; 95% CI, 10.21-28.48; and aOR for accreta, 7.62; 95% CI, 4.83-12.01). Patients who had AFE were more likely to have coagulopathy (aOR, 24.68; 95% CI, 19.38-31.44), cardiac arrest (aOR, 24.56; 95% CI, 17.84-33.81), and adult respiratory distress syndrome (aOR, 10.72; 95% CI, 8.09-14.20). The failure-to-rescue rate after AFE was 17.0% overall. However, the failure-to-rescue rate exceeded 30% when AFE co-occurred with other severe maternal morbidity indicators: 45.8% for AFE, cardiac arrest, and coagulopathy; 43.2% for AFE, shock, and cardiac rhythm conversion; and 38.6% for AFE, cardiac arrest, coagulopathy, and shock. The failure-to-rescue rate after AFE also exceeded 30% when AFE occurred in the setting of placental pathology: 42.9% for AFE and PAS and 31.3% for AFE and placental abruption. Conclusions and Relevance: This contemporaneous, national-level analysis validated previously known risk factors for AFE and confirmed the dismal outcomes of pregnancy complicated by AFE. The association between PAS and AFE, which was not previously reported, warrants further investigation.

Acute ST-Elevation Myocardial Infarction During Labor Due to Amniotic Fluid Embolism.

BACKGROUND Amniotic fluid embolism (AFE) is an extremely rare, life-threatening complication of labor that leads to hyper-acute induction of inflammation and disseminated intravascular coagulation (DIC). Usually, acute pulmonary hypertension results in acute right ventricular failure, while DIC manifests by hemorrhagic and ischemic complications, ultimately leading to multi-organ failure and death. CASE REPORT A 30-year-old primigravida and primipara woman with no prior medical history was admitted for labor after intrauterine fetal death at 37 weeks of gestation. After medical birth induction, she had a convulsive seizure and cardiorespiratory arrest. Short mechanical resuscitation was performed before spontaneous circulation returned. Simultaneously occurring severe vaginal hemorrhage and an ST-elevation myocardial infarction (STEMI) triggered the diagnosis of AFE. Laboratory results fulfilled the criteria for DIC, and hemostatic resuscitation and mechanical hemostasis were performed. Transesophageal echocardiography revealed hypokinesia to akinesia of the inferior wall. Owing to the ongoing DIC, coronary angiography could not be performed. After the patient's transfer to the Intensive Care Unit, ST-segment elevations resolved and the myocardial infarct was managed medically. Cardiac magnetic resonance imaging performed 3 months later demonstrated myocardial scarring in 2 different areas. Referring to the coronary artery anatomy in a computed tomography scan of the chest, the infarcted areas correlated with 2 different coronary supply territories. CONCLUSIONS AFE should be considered in women with acute cardiorespiratory failure during labor. This is the first report of a STEMI triggered by an AFE. The 2 separate areas of infarction, corresponding to the 2 different coronary territories, suggest an AFE-related thrombotic/thromboembolic etiology.

Acute respiratory distress and amniotic fluid embolism in pregnancy.

Respiratory failure in pregnant and postpartum women is uncommon, but it is one of the leading causes of maternal admission into the intensive care unit and is associated with high mortality. The underlying causes include sequelae of underlying medical conditions, such as congenital heart diseases, but it is more often related to acute respiratory distress syndrome from obstetric complications like pre-eclampsia, effect of treatment like tocolysis, coincidental to pregnancy like transfusion-related acute lung injury, and accidental like amniotic fluid embolism. The pathophysiological mechanisms involved in many of these conditions remain to be clearly established, but maternal inflammatory response and activation of the immune and complement systems appear to play leading roles. Prompt recognition of maternal respiratory distress and related manifestations and aggressive and adequate supportive treatment, especially cardiopulmonary resuscitation, ventilation, maintenance of circulation, and timely termination of the pregnancy, play key roles in achieving survival of both mother and foetus.

Sudden respiratory and circulatory collapse after cesarean section: Amniotic fluid embolism or other reasons? - a case report.

BACKGROUND: For a healthy parturient, a cardiopulmonary collapse that suddenly occurs shortly after an uneventful caesarean section is a relatively rare event and presents a significant challenge for the anesthesia provider. CASE PRESENTATION: Amniotic fluid embolism (AFE) is characterized by acute and rapid collapse and is well known to the obstetric team. Our patient experienced sudden cardiovascular collapse, severe respiratory difficulty and hypoxia, in the absence of other explanations for these findings at the time, and thus AFE was immediately become the focus of the consideration. However, there is no quick, standard laboratory test for AFE, therefore the diagnosis is one of exclusion based on presenting symptoms and clinical course. After given symptomatic treatment, the patient made an uneventful initial recovery in a short period and developed a rash. We recognized that the postpartum shock was associated with delayed anaphylaxis of antibiotics. CONCLUSIONS: These observations have implications for understanding whenever administering drugs in surgery, which may affect the anesthesiologist's judgment regarding the complications of anesthesia. Even though serious complications of common perioperative drugs may rarely occur, anesthesia providers should be aware of the consideration. Early recognition and effective treatment are more important than prompt diagnosis.

Successful ECMO-assisted open chest cardiopulmonary resuscitation in a postpartum patient with delayed amniotic fluid embolism.

BACKGROUND: Amniotic fluid embolism (AFE) is a rare but potentially dangerous severe obstetrics complication, which is accompanied by an incidence between 1.9 and 6.1 per 100,000 births. CASE PRESENTATION: Here, we report an AFE case after cesarean delivery diagnosed on a cardiac arrest complicated by acute respiratory distress syndrome and coagulopathy. Diagnosis, risk factors and pathophysiology for AFE have been fully discussed, besides, extracorporeal membrane oxygenation in the early management of cardiac arrest was used, describing the indication, efficacy and successful performed of open-chest cardiopulmonary resuscitation for the patient. CONCLUSION: In AFE with cute cardiovascular collapse, extracorporeal membrane oxygenation support can be considered as the alternative therapies.

, , ACUTE PULMONARY EMBOLISM BY AMNIOTIC FLUID - A RARE COMPLICATION OF PERINATAL PERIOD THAT SHOULD NOT BE FORGOTTEN.

OBJECTIVE: Amniotic fluid embolism (AFE) is a diagnostically challenging type of pulmonary embolism that occurs when amniotic fluid enters maternal circulation during delivery or postpartum. This obstetric complication is very rare but characterized by high mortality rate. The main symptoms are dyspnea, cardiovascular collapse, disseminated intravascular coagulation (DIC) and even sudden cardiac death. The aim of the article is to draw attention to AFE as a rare but possible and catastrophic complication of perinatal period. The authors present a 28-year-old woman who was admitted to obstetric ward during the first stage of labour. The patient developed sudden deterioration of her medical state with acute respiratory distress symptoms. An emergency cesarean section was performed, complicated by excessive bleeding. After a detailed assessment of the patient's condition and evaluation of the results of additional tests, we diagnosed AFE as the cause of the patient's deterioration. CONCLUSION: Conclusions: The case study shows how unpredictable, unpreventable and dangerous is AFE. It is still one of the main causes of maternal deaths in developed countries. Four diagnostic criteria proposed by the Society for Maternal-Fetal Medicine (SMFM) may accelerate diagnosis. AFE as a medical emergency, requires immediate multidisciplinary response and aggressive treatment. The initial medical care may be facilitated by the application of the general guidelines recommended by SMFM. The case report also emphasizes the need for further research on this disease, in particular on early detection and prevention.

Acute inflammation in the uterine isthmus coincides with postpartum acute myometritis in the uterine body involving refractory postpartum hemorrhage of unknown etiology after cesarean delivery.

Uterine atony is a major cause of postpartum hemorrhage. We recently proposed the new histological concept of postpartum acute myometritis (PAM) for the pathophysiology of refractory uterine atony of unknown etiology, which is characterized by the diffuse activation of mast cells and the complement system as well as the massive infiltration of macrophages and neutrophils into the uterine body. We herein focused on the uterine isthmus just adjacent to the body. The isthmus becomes significantly elongated throughout pregnancy. It is composed of myocytes and fibroblasts with an extracellular matrix that forms a passive lower segment during labor. The aim of this study was to histologically examine the uterine isthmus in cases of PAM in the uterine body. Under the amniotic fluid embolism-registry program in Japan, we selected PAM cases from uterine samples obtained by cesarean hysterectomy and delivered to us for analyses between 2011 and 2017. Control tissues were collected during elective cesarean section. We investigated the isthmus tissues of these cases and performed immunohistochemistry for inflammatory cell markers, i.e. neutrophil elastase, mast cell tryptase, CD68, CD3, and C5a receptor (C5aR). The numbers of tryptase-positive degranulating mast cells, elastase-positive neutrophils, CD68-positive macrophages, and C5aR-positive cells in the isthmus were significantly higher in uteri with PAM in the body than in controls without PAM. CD3 was negative in both groups. In conclusion, inflammation and an anaphylactoid reaction were histologically detected not only in the uterine body, but in the isthmus among cases of refractory PPH of unknown etiology after cesarean section.

Case report of amniotic fluid embolism coagulopathy following abortion; use of viscoelastic point-of-care analysis.

BACKGROUND: Amniotic fluid embolism (AFE) is a rare, life threatening obstetric complication, often associated with severe coagulopathy. Induced abortions are extremely safe procedures however complications including AFE can occur. CASE PRESENTATION: A 29-year-old previously healthy woman, gravida 1 para 0, presented for a scheduled second trimester induced abortion via dilation and evacuation at 22-weeks gestation. The case was complicated by a suspected AFE with associated profound coagulopathy. Viscoelastic point-of-care coagulation analysis was used to successfully and swiftly guide management of her coagulopathy. CONCLUSION: AFE can occur in the setting of induced abortion. This case report suggests viscoelastic point-of-care coagulation analyzers may aid in the management of pregnancy-related coagulopathy by providing faster coagulation assessment than laboratory testing, and facilitating timely, targeted management of coagulopathy.

Risk factors, management, and outcomes of amniotic fluid embolism: A multicountry, population-based cohort and nested case-control study.

BACKGROUND: Amniotic fluid embolism (AFE) remains one of the principal reported causes of direct maternal mortality in high-income countries. However, obtaining robust information about the condition is challenging because of its rarity and its difficulty to diagnose. This study aimed to pool data from multiple countries in order to describe risk factors, management, and outcomes of AFE and to explore the impact on the findings of considering United Kingdom, international, and United States AFE case definitions. METHODS AND FINDINGS: A population-based cohort and nested case-control study was conducted using the International Network of Obstetric Survey Systems (INOSS). Secondary data on women with AFE (n = 99-218, depending on case definition) collected prospectively in population-based studies conducted in Australia, France, the Netherlands, Slovakia, and the UK were pooled along with secondary data on a sample of control women (n = 4,938) collected in Australia and the UK. Risk factors for AFE were investigated by comparing the women with AFE in Australia and the UK with the control women identified in these countries using logistic regression. Factors associated with poor maternal outcomes (fatality and composite of fatality or permanent neurological injury) amongst women with AFE from each of the countries were investigated using logistic regression or Wilcoxon rank-sum test. The estimated incidence of AFE ranged from 0.8-1.8 per 100,000 maternities, and the proportion of women with AFE who died or had permanent neurological injury ranged from 30%-41%, depending on the case definition. However, applying different case definitions did not materially alter findings regarding risk factors for AFE and factors associated with poor maternal outcomes amongst women with AFE. Using the most liberal case definition (UK) and adjusting for the severity of presentation when appropriate, women who died were more likely than those who survived to present with cardiac arrest (89% versus 40%, adjusted odds ratio [aOR] 10.58, 95% confidence interval [CI] 3.93-28.48, p < 0.001) and less likely to have a source of concentrated fibrinogen (40% versus 56%, aOR 0.44, 95% CI 0.21-0.92, p = 0.029) or platelets given (24% versus 49%, aOR 0.23, 95% CI 0.10-0.52, p < 0.001). They also had a lower dose of tranexamic acid (median dose 0.7 g versus 2 g, p = 0.035) and were less likely to have had an obstetrician and/or anaesthetist present at the time of the AFE (61% versus 75%, aOR 0.38, 95% CI 0.16-0.90, p = 0.027). Limitations of the study include limited statistical power to examine factors associated with poor maternal outcome and the potential for residual confounding or confounding by indication. CONCLUSIONS: The findings of our study suggest that when an AFE is suspected, initial supportive obstetric care is important, but having an obstetrician and/or anaesthetist present at the time of the AFE event and use of interventions to correct coagulopathy, including the administration of an adequate dose of tranexamic acid, may be important to improve maternal outcome. Future research should focus on early detection of the coagulation deficiencies seen in AFE alongside the role of tranexamic acid and other coagulopathy management strategies.

Venoarterial Extracorporeal Membrane Oxygenation as Supportive Therapy After Cardiac Arrest After Amniotic Fluid Embolism: A Case Report.

Amniotic fluid embolism is a rare but dreaded complication of pregnancy, with an incidence between 2 and 7/100,000 deliveries. We report an amniotic fluid embolism after urgent cesarean delivery diagnosed on a cardiac arrest, complicated by cardiogenic shock and acute respiratory distress syndrome. This report describes the indication, efficacy, and success of venoarterial extracorporeal membrane oxygenation in the early management of cardiac arrest, cardiac failure driven by amniotic fluid embolism, and acute respiratory distress syndrome. The use of venoarterial extracorporeal membrane oxygenation support after recovery from cardiac arrest after amniotic fluid embolism should be considered early during the management of these cases.

Amniotic Fluid Embolism: A Rare Complication of Second-Trimester Amniocentesis.

Amniotic fluid embolism occurring following diagnostic amniocentesis is extremely rare. Only 2 cases have been reported in the English literature over the past 55 years, the most recent one approximately 3 decades ago. We present a case of amniocentesis at 24 weeks' gestation that was performed as part of an evaluation of abnormal fetal ultrasound findings. Immediately following amniotic fluid aspiration, maternal hemodynamic collapse occurred, initially diagnosed and treated as anaphylactic shock. Shortly after initial therapy, coagulopathy was noted and amniotic fluid syndrome suspected. Rapid response restored maternal hemodynamic stability; however, the fetus had suffered fatal damage.

Amniotic Fluid Embolism.

Amniotic fluid embolism remains one of the most devastating conditions in obstetric practice with an incidence of approximately 1 in 40,000 deliveries and a reported mortality rate ranging from 20% to 60%. The pathophysiology involves an abnormal maternal response to fetal tissue exposure associated with breaches of the maternal-fetal physiologic barrier during parturition. This response and its subsequent injury involve activation of proinflammatory mediators similar to that seen with the classic systemic inflammatory response syndrome. Maternal treatment is primarily supportive, whereas prompt delivery in the mother who has sustained cardiopulmonary arrest is critical for improved newborn outcome.

Successful recovery after amniotic fluid embolism in a patient undergoing vacuum-assisted vaginal delivery.

Amniotic fluid embolism (AFE) is a rare, catastrophic emergency that requires prompt recognition and treatment. Despite early recognition and supportive therapy, the morbidity and mortality remain high. We report a case of AFE after vacuum-assisted vaginal delivery resulting in hemodynamic collapse and subsequent multiorgan failure. Management included mechanical ventilation, extracorporeal membrane oxygenation, and continuous veno-venous hemodialysis. The patient was able to make a full recovery with minimal sequelae. In AFE with multiorgan failure, extracorporeal membrane oxygenation and continuous veno-venous hemodialysis can be valuable therapies. Proper management requires effective communication and the combined efforts of physicians of several disciplines.

Amniotic Fluid Embolism: Using the Medical Staff Process to Facilitate Streamlined Care.

Amniotic fluid embolism (AFE) is a catastrophic consequence of labor and delivery that often results in maternal and neonatal death. These poor outcomes are related largely to the rarity of the event in a population overwhelmingly biased by overall good health. Despite the presence of national AFE registries, there are no published algorithmic approaches to its management, to our knowledge. The purpose of this article is to share a care pathway developed by a multidisciplinary group at a community teaching hospital. Post hoc analysis of a complicated case of AFE resulted in development of this pathway, which addresses many of the major consequences of AFE. We offer this algorithm as a template for use by any institution willing to implement a clinical pathway to treat AFE. It is accompanied by the remarkable case outcome that prompted its development.

Koagulopatia ze zuzycia jako wiodacy objaw zatoru plynem owodniowym -opis przypadku.

Amniotic fluid embolism is a rare and diagnostically challenging obstetric disease of high mortality rate. We present a case of a 33-year old parturient after vaginal birth, who presented with severe hemorrhagic shock with low platelet count and coagulopathy resistant to treatment with plasma, platelets and coagulation factors and despite of surgical management of bleeding. Laboratory findings revealed consumptive coagulopathy. Other symptoms included dyspnea and atelectatic changes on chest x-ray, together with augmentation of the heart with no proof of ventricular insufficiency in echocardiographic examination. The suspected reason of these alterations was amniotic fluid embolism. The patient survived and came back to her usual activity after 22 days of treatment.