Amniotic fluid embolism: a reappraisal.

OBJECTIVES: Using cases from our own experience and from the published literature on amniotic fluid embolism (AFE), we seek to improve on existing criteria for diagnosis and discern associated risk factors. Additionally, we propose a novel theory of pathophysiology. METHODS: This retrospective case review includes eight cases of AFE from two hospital systems and 21 from the published literature. All cases were evaluated using the modified criteria for research reporting of AFE by Clark et al. in Am J Obstet Gynecol, 2016;215:408-12 as well as our proposed criteria for diagnosis. Additional clinical and demographic characteristics potentially correlated with a risk of AFE were included and analyzed using descriptive analysis. RESULTS: The incidence of AFE was 2.9 per 100,000 births, with five maternal deaths in 29 cases (17.2 %) in our series. None of the cases met Clark's criteria while all met our criteria. 62.1 % of patients were over the age of 32 years and two out of 29 women (6.9 %) conceived through in-vitro fertilization. 6.5 % of cases were complicated by fetal death. Placenta previa occurred in 13.8 %. 86.2 % of women had cesarean sections of which 52.0 % had no acute maternal indication. CONCLUSIONS: Our criteria identify more patients with AFE than others with a low likelihood of false positives. Clinical and demographic associations in our review are consistent with those previously reported. A possible relationship between cesarean birth and risk of AFE was identified using our criteria. Additionally, we propose a new hypothesis of pathophysiology.

Current concepts in the use of cell salvage in obstetrics.

PURPOSE OF REVIEW: The worldwide leading cause of maternal death is severe maternal hemorrhage. Maternal hemorrhage can be profound leading to an entire loss of blood volume. In the past two decades, Patient Blood Management has evolved to improve patient's care and safety. In surgeries with increased blood loss exceeding 500 ml, the use of cell salvage is strongly recommended in order to preserve the patient's own blood volume and to minimize the need for allogeneic red blood cell (RBC) transfusion. In this review, recent evidence and controversies of the use of cell salvage in obstetrics are discussed. RECENT FINDINGS: Numerous medical societies as well as national and international guidelines recommend the use of cell salvage during maternal hemorrhage. SUMMARY: Intraoperative cell salvage is a strategy to maintain the patient's own blood volume and decrease the need for allogeneic RBC transfusion. Historically, cell salvage has been avoided in the obstetric population due to concerns of iatrogenic amniotic fluid embolism (AFE) or induction of maternal alloimmunization. However, no definite case of AFE has been reported so far. Cell salvage is strongly recommended and cost-effective in patients with predictably high rates of blood loss and RBC transfusion, such as women with placenta accreta spectrum disorder. However, in order to ensure sufficient practical experience in a multiprofessional obstetric setting, liberal use of cell salvage appears advisable.

Massive platelet-rich thrombus formation in small pulmonary vessels in amniotic fluid embolism: An autopsy study.

OBJECTIVE: To identify pulmonary/uterine thrombus formation in amniotic fluid embolism (AFE). DESIGN: Retrospective, observational. SETTING: Nationwide. POPULATION: Eleven autopsy cases of AFE and control cases. METHODS: We assessed pulmonary and uterine thrombus formation and thrombus area in AFE and pulmonary thromboembolism (PTE) as a control. The area of platelet glycoprotein IIb/IIIa, fibrin, neutrophil elastase, citrullinated histone H3 (a neutrophil extracellular trap marker) and mast cell chymase immunopositivity was measured in 90 pulmonary emboli, 15 uterine thrombi and 14 PTE. MAIN OUTCOME MEASURES: Pathological evidence of thrombus formation and its components in AFE. RESULTS: Amniotic fluid embolism lung showed massive thrombus formation, with or without amniotic emboli in small pulmonary arteries and capillaries. The median pulmonary thrombus size in AFE (median, 0.012 mm2 ; P < 0.0001) was significantly smaller than that of uterine thrombus in AFE (0.61 mm2 ) or PTE (29 mm2 ). The median area of glycoprotein IIb/IIIa immunopositivity in pulmonary thrombi in AFE (39%; P < 0.01) was significantly larger than that of uterine thrombi in AFE (23%) and PTE (15%). The median area of fibrin (0%; P < 0.001) and citrullinated histone H3 (0%; P < 0.01) immunopositivity in pulmonary thrombi in AFE was significantly smaller than in uterine thrombi (fibrin: 26%; citrullinated histone H3: 1.1%) and PTE (fibrin: 42%; citrullinated histone H3: 0.4%). No mast cells were identified in pulmonary thrombi. CONCLUSIONS: Amniotic fluid may induce distinct thrombus formation in the uterus and lung. Pulmonary and uterine thrombi formation may contribute to cardiorespiratory collapse and/or consumptive coagulopathy in AFE.

Echocardiography findings in amniotic fluid embolism: a systematic review of the literature.

PURPOSE: Amniotic fluid embolism (AFE) is a leading cause of obstetrical cardiac arrest and maternal morbidity. The pathogenesis of hemodynamic collapse is thought to be from right ventricular (RV) failure; however, there is a paucity of data documenting echocardiography findings in this population. We undertook a systematic review of the literature to evaluate the echocardiography findings in patients with AFE. SOURCES: We retrieved all case reports and case series reporting AFE in Embase and MEDLINE from inception to 20 November 2021. Studies reporting AFE diagnosed by fulfilling at least one of three different proposed AFE criteria and echocardiography findings during hospitalization were included. Patient and echocardiographic data were retrieved, and univariate logistic regression analysis was performed for outcomes of interest. Bias was assessed using the Joanna Briggs Institute clinical appraisal tool for case series. PRINCIPAL FINDINGS: Eighty publications reporting on 84 patients were included in the final review. Fifty-five out of 82 patients with data (67%) showed RV dysfunction, including 11/82 (13%) with biventricular dysfunction; 14/82 (17%) had normal systolic function. No data on RV or left ventricular function were reported for two patients. The presence of RV dysfunction on echocardiography was associated with cardiac arrest (odds ratio [OR], 3.66; 95% confidence interval [CI], 1.39 to 9.67; P = 0.009), and a composite risk of cardiac arrest, maternal death or use of extracorporeal membrane oxygenation (OR, 3.86; 95% CI, 1.43 to 10.4; P = 0.007). A low risk of bias was observed in 15/84 (18%) cases. CONCLUSIONS: Right ventricular dysfunction on echocardiography is a common finding in AFE and is associated with a high risk of cardiac arrest. The finding of RV dysfunction on echocardiography may help diagnose AFE and help triage the highest risk patients with AFE. STUDY REGISTRATION: PROSPERO (CRD42021271323); registered 1 September 2021.

RéSUMé: OBJECTIF: L'embolie amniotique (EA) est l'une des principales causes d'arrêt cardiaque obstétrical et de morbidité maternelle. Il est présumé que la pathogenèse du choc hémodynamique provient d'une défaillance ventriculaire droite (VD). Cependant, il y a peu de données documentant les constatations de l'examen échocardiographique dans cette population. Nous avons effectué une revue systématique des données probantes visant à évaluer l'utilité de l'échocardiographie chez les patientes atteintes d'embolie amniotique. SOURCES: Nous avons évalué tous les rapports de cas et séries de cas rapportant une EA dans les bases de données Embase et MEDLINE de leur création jusqu'au 20 novembre 2021. Les études rapportant une EA diagnostiquée en remplissant au moins l'un des trois critères d'EA proposés et les résultats échocardiographiques pendant l'hospitalisation ont été incluses. Les données sur les patientes et échocardiographiques ont été colligées, et une analyse de régression logistique univariée a été effectuée pour les issues cliniques d'intérêt. Le risque de biais a été évalué à l'aide de l'outil d'évaluation clinique de l'Institut Joanna Briggs pour les séries de cas. CONSTATATIONS PRINCIPALES: Quatre-vingts publications incluant 84 patientes ont été incluses dans la revue finale. Cinquante-cinq des 82 patientes présentant des données (67 %) avaient une dysfonction du VD incluant 11/82 (13 %) avec une dysfonction biventriculaire. Quatorze patientes sur 82 (17 %) avaient une fonction systolique normale. Aucune donnée sur la fonction du ventricule droit ou gauche n'a été rapportée pour deux patientes. La présence d'une dysfonction du VD à l'échocardiographie était associée à un arrêt cardiaque (rapport de cotes [RC], 3,66; intervalle de confiance à 95 % [IC], 1,39 à 9,67; P = 0,009), et à un risque composite d'arrêt cardiaque, de décès maternel ou d'utilisation de l'oxygénation par membrane extracorporelle (ECMO) (RC, 3,86; IC 95 %, 1,43 à 10,4; P = 0,007). Un faible risque de biais a été observé dans 15/84 (18 %) des cas. CONCLUSION: La dysfonction ventriculaire droite à l'échocardiographie est une constatation courante dans l'embolie amniotique et est associée à un risque élevé d'arrêt cardiaque. La découverte d'une dysfonction du VD à l'échocardiographie peut aider à diagnostiquer l'embolie amniotique et à identifier les patientes atteintes d'embolie amniotique les plus à risque. ENREGISTREMENT DE L'éTUD: PROSPERO (CRD42021271323); enregistrée le 1er septembre 2021.

Fatal amniotic fluid embolism: incidence, risk factors and influence on perinatal outcome.

PURPOSE: This study aimed to estimate the incidence of fatal amniotic fluid embolism, describe its risk factors, and analyze perinatal outcomes. METHODS: Maternity cases and newborn records of amniotic fluid embolism were collected from the Zhejiang Maternal Surveillance System from October 2006 to October 2019. This study strictly limited the diagnostic criteria for AFE and excluded suspicious cases in order to minimize false-positive AFE cases. The risk factors of fatal amniotic fluid embolism and the relationship between perinatal prognosis and AFE were investigated using logistic regression analysis, estimating the adjusted odds ratios (aORs) and 95% confidence intervals (CIs). RESULTS: 149 cases of amniotic fluid embolism were registered, of which 80 cases were fatal. The estimated fatal AFE incidence was 0.99 per 100,000. The occurrence of fatal AFE was significantly correlated with spontaneous vaginal delivery (aOR 12.3, 95% CI 3.3-39.2) and cardiac arrest (aOR 64.8, 95% CI 14.6-287.8). The average diagnosis time of fatal AFE is 85.51 min, and the peak period of female death is 1-12 h after the onset of the disease, accounting for 60% (48/80) of cases. Fatal amniotic embolism is a cause of intrauterine fetal death and fetal death during delivery (aOR 11.957, 95% CI 1.457-96.919; aOR 13.152, 95% CI 1.636-105.723). Of the 149 confirmed AFE cases, 11 cases of stillbirth occurred, 12 cases were stillborn, and 7 cases of neonatal death were reported. The perinatal mortality rate was 202 per 1000. CONCLUSIONS: Early detection, diagnosis, and treatment of amniotic fluid embolism are essential to avoiding fatal AFE. Clinicians should fully evaluate the pros and cons of choosing the delivery method for pregnant women. When cardiac arrest occurs in women with amniotic fluid embolism, obstetricians should be particularly careful and provide timely and effective treatment to minimize the fatality rate. The outcome of AFE is not only related to maternal survival but also plays a decisive role in the prognosis of the infant over the perinatal period.

Amniotic fluid embolism rescued by venoarterial extracorporeal membrane oxygenation.

BACKGROUND: Amniotic fluid embolism (AFE) is a rare but often catastrophic complication of pregnancy that leads to cardiopulmonary dysfunction and severe disseminated intravascular coagulopathy (DIC). Although few case reports have reported successful use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) with AFE, concerns can be raised about the increased bleeding risks with that device. METHODS: This study included patients with AFE rescued by VA-ECMO hospitalized in two high ECMO volume centers between August 2008 and February 2021. Clinical characteristics, critical care management, in-intensive care unit (ICU) complications, and hospital outcomes were collected. ICU survivors were assessed for health-related quality of life (HRQL) in May 2021. RESULTS: During that 13-year study period, VA-ECMO was initiated in 54 parturient women in two high ECMO volume centers. Among that population, 10 patients with AFE [median (range) age 33 (24-40), SAPS II at 69 (56-81)] who fulfilled our diagnosis criteria were treated with VA-ECMO. Pregnancy evolved for 36 (30-41) weeks. Seven patients had a cardiac arrest before ECMO and two were cannulated under cardiopulmonary resuscitation. Pre-ECMO hemodynamic was severely impaired with an inotrope score at 370 (55-1530) µg/kg/min, a severe left ventricular ejection fraction measured at 14 (0-40)%, and lactate at 12 (2-30) mmol/L. 70% of these patients were alive at hospital discharge despite an extreme pre-ECMO severity and massive blood product transfusion. However, HRQL was lower than age-matched controls and still profoundly impaired in the role-physical, bodily pain, and general health components after a median of 44 months follow-up. CONCLUSION: In this rare per-delivery complication, our results support the use of VA-ECMO despite intense DIC and ongoing bleeding. Future studies should focus on customized, patient-centered, rehabilitation programs that could lead to improved HRQL in this population.

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.

Can cell salvage be used for resuscitation in a patient with amniotic fluid embolism and hepatic laceration? A case report.

BACKGROUND: Amniotic fluid embolism (AFE) is a rare disease that can lead to profound coagulopathy and hemorrhage, especially when combined with the laceration and bleeding of other organs. Intraoperative cell salvage (ICS) has been widely used for treating obstetric hemorrhage, but it remains unclear whether ICS can be used in the treatment of AFE. CASE PRESENTATION: We report the case of a 27-year-old woman at 39 weeks' gestation who suddenly developed severe abdominal pain, convulsions, loss of consciousness, and decreased vital signs during labor. Despite an emergency cesarean section being performed, the parturient experienced sudden cardiac arrest. Fortunately, the heart rate spontaneously recovered after effective cardiopulmonary resuscitation (CPR). Further abdominal exploration revealed right hepatic laceration with active bleeding. ICS was performed and the salvaged blood was promptly transfused back to the patient. Subsequently, the patient was diagnosed with AFE based on hypotension, hypoxia, coagulopathy, and cardiac arrest. The patient was transfused with 2899 mL salvaged blood during surgery with no adverse effects. At 60- and 90-day follow-ups, no complaints of discomfort or abnormal laboratory test results were observed in the mother or the baby. CONCLUSION: ICS was used to rescue patient with AFE, and ICS did not worsen the condition of patients with AFE. For pregnant women who received CPR, clinicians should explore the presence of hepatic laceration which can be fatal to patients.

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.

Amniotic fluid embolism - review and multicentric case analysis.

Amniotic fluid embolism (AFE) is a rare and often fatal obstetric complication, characterized by sudden cardiovascular collapse, dyspnea, seizures, mental alteration or coma and laboratory and clinically dia-gnosed disseminated intravascular coagulation (DIC). Patients reaction is typically biphasic with initial pulmonary hypertension and right ventricular failure, followed by left ventricular failure during or immediately right after labor. Early recognition of AFE is critical to a successful survival. Aggressive shock management is needed in collaboration with an anesthesiologist. Several aspects of the condition remain a controversy. This review critically examines, from the best available evidence, the current knowledge regarding the epidemiology, pathophysiology, dia-gnosis, and available treatment of AFE. This dia-gnosis still determines perinatal morbidity and mortality and potential permanent neurological symptoms for surviving patients.

Severe maternal morbidity in the Slovak Republic in the years 2012-2018.

OBJECTIVE: Analysis of maternal morbidity in the Slovak Republic in the years 2012-2018. METHODS: The analysis of selected maternal morbidity data prospectively collected in the years 2012-2018 from all obstetric units in the Slovak Republic. RESULTS: In the years 2012-2018, incidence of severe peripartum bleeding was 2.17, peripartum hysterectomy was 0.89, maternal admission to intensive care units was 1.59, eclampsia was 0.21, HELLP syndrome was 0.73, abnormally invasive placentation was 0.37, uterine rupture was 0.68, severe sepsis in pregnancy and puerperium was 0.18 and nonfatal amniotic fluid embolism was 0.027 per 1,000 births. CONCLUSION: Incidence of total severe acute maternal morbidity in the Slovak Republic was 6.84 per 1,000 births. In Slovak local conditions, there is still room for reduction of severe acute maternal morbidity.

Perimortem Cesarean Section in a Patient with Intrapartum Cardiorespiratory Arrest Due to a Massive Amniotic Fluid Embolism.

We report and discuss the case of a 29-year-old tercigravida with intrapartum cardiorespiratory arrest due to a massive amniotic fluid embolism and disseminated intravascular coagulopathy. Perimortem caesarean section with B-Lynch compression uterine suture with simultaneous fetal and maternal resuscitation were performed with a favorable outcome for both the mother and the child.

Society for Maternal-Fetal Medicine Special Statement: Checklist for initial management of amniotic fluid embolism.

Amniotic fluid embolism is a rare syndrome characterized by sudden cardiorespiratory collapse during labor or soon after delivery. Because of its rarity, many obstetrical providers have no experience in managing amniotic fluid embolism and may therefore benefit from a cognitive aid such as a checklist. We present a sample checklist for the initial management of amniotic fluid embolism based on standard management guidelines. We also suggest steps that each facility can take to implement the checklist effectively.

Technical note: double immunohistochemical stain (anti-CD31 and anti-cytokeratins) as a tool for a confident forensic post-mortem diagnosis of amniotic fluid embolism.

Amniotic fluid embolism (AFE) is a rare cause of unexpected late maternal gestational death. The forensic post-mortem diagnosis is rendered upon the histological recognition of fetal "foreign" material inside maternal lung vasculature. The authors propose a double immunohistochemical (anti-CD31 plus anti-cytokeratin AE1/AE3) stain in order to assess accurate amniotic fluid pulmonary embolic burden in a highly reproducible fashion based on the fact that such technique allows to detect an impressive amount of scales within lung vasculature, thereby offering further evidence that pulmonary embolic obstructive microangiopathy, rather than anaphylactoid reaction, is major determinant in AFE-related death.

Contribution of blood detection of insulin-like growth factor binding protein-1 for the diagnosis of amniotic-fluid embolism: a retrospective multicentre cohort study.

OBJECTIVE: To assess the contribution of maternal blood detection of IGFBP-1 for the diagnosis of amniotic-fluid embolism in clinical daily practice. DESIGN: A retrospective multicentre cohort study. SETTING: Three tertiary care obstetric units in France. SAMPLE: Data of 86 women for whom amniotic-fluid embolism had been suspected and maternal serum detection of IGFBP-1 had been performed between 2011 and 2019 were analysed. METHODS: The criteria defined by the United Kingdom Obstetric Surveillance System (UKOSS) were used for the retrospective diagnosis of amniotic-fluid embolism. The more structured definition proposed by the Society for Maternal-Fetal Medicine and the Amniotic Fluid Embolism Foundation (SMFM) was also used as secondary endpoint. MAIN OUTCOME MEASURES: Agreements between biological and clinical assessments were tested. The performance of blood detection of IGFBP-1 for the diagnosis of amniotic-fluid embolism according to the UKOSS criteria, and to the SMFM definition, was also assessed. RESULTS: There was only slight agreement between clinical and laboratory diagnosis of amniotic-fluid embolism (Cohen's Kappa coefficient: 0.04). Blood detection of IGFBP-1 had a sensitivity of 16%, a specificity of 88%, a positive and a negative likelihood ratio of 1.3 and 0.95, respectively, and a positive and a negative predictive value of 58 and 50%, respectively, for the diagnosis of amniotic-fluid embolism based on the UKOSS criteria. The use of the more structured SMFM definition of amniotic-fluid embolism did not substantially change the results. CONCLUSION: These results question the usefulness of blood detection of IGFBP-1 for the early diagnosis of amniotic-fluid embolism in daily clinical practice. TWEETABLE ABSTRACT: This retrospective multicentre study questions the contribution of IGFBP-1 detection for the diagnosis of AFE.

Maternal cardiac arrest: a retrospective analysis.

OBJECTIVES: To describe the characteristics and factors which may influence the maternal outcomes of maternal cardiac arrest (MCA). DESIGN: Retrospective analysis of cases. SETTING: China. POPULATION OR SAMPLE: A total of 61 MCA patients admitted or transferred to The Third Affiliated Hospital of Guangzhou Medical University from January 2000 to December 2019. METHODS: Clinical data for MCA were analysed retrospectively. The indicators included maternal age; BMI; gestational age; antenatal examination; income; MCA cause and place; cardiopulmonary resuscitation (CPR); mode of delivery; maternal prognosis; and neonatal outcome. MAIN OUTCOME MEASURES: The impact of case characteristics on maternal prognosis of MCA. RESULTS: The hospital received 61 patients with MCA, 36 of whom died (mortality 59.0%, 95% CI 46.3-71.7%). MCA was predominantly caused by treatable complications. Those who died were more likely to have collapsed in the ICU. CONCLUSIONS: Regular antenatal examination and early intervention can reduce the incidence of adverse pregnancy outcomes. The location of MCA occurred may be related to maternal prognosis. The leading causes of MCA were postpartum haemorrhage and amniotic fluid embolism. TWEETABLE ABSTRACT: A retrospective analysis describes the correlation between case characteristics of MCA and maternal outcomes.

Excessive fibrinolysis detected with thromboelastography in a case of amniotic fluid embolism: fibrinolysis may precede coagulopathy.

Amniotic fluid embolism (AFE) is a catastrophic condition in the peripartum period and still remains as a leading cause of maternal death. Although over 80% of cases of AFE cases are accompanied by coagulopathy, the pathology of disseminated intravascular coagulation is not well understood not only because of its rarity but also because of the limited availability of laboratory testing in emergent clinical settings. We describe a case of AFE whose characteristic data for coagulation and fibrinolysis were timely depicted with sequential thromboelastography. We believe that the point-of-care, which provides information for both coagulopathy and fibrinolysis, may provide crucial data not only for the treatment of postpartum hemorrhage in daily clinical practice but also for the elucidation of AFE pathophysiology.

Maternal death analysis based on data from the nationwide registration system in Japan (2010-2018).

The maternal mortality rate in Japan was 3.5 per 100 000 live births in 2017, similar to that reported in other developed countries. To reduce the number of maternal deaths, a Japanese nationwide registration and analysis system was implemented in 2010. Between January 2010 and April 2018, 367 maternal deaths were reported. Among them, by reviewing 80 autopsy records, the direct obstetric causes of death were identified in 52 women. The major causes of deaths were amniotic fluid embolism and acute pulmonary thromboembolism. The other 26 maternal deaths were associated with indirect obstetric causes including invasive Group A Streptococcus infection, aortic dissection, cerebral stroke and cardiomyopathies. This review highlights the importance of autopsy in maternal deaths. On analyzing 42 autopsy specimens obtained from registered cases of maternal death during 2012-2015, the 36% of causes of death by autopsy were discordant with the clinical diagnosis. Moreover, of the 38% of non-autopsied maternal death, the cause of death could not be clarified from the clinical chart. We emphasized that detailed autopsies are necessary to clarify the precise pathologic evidence related to pregnancy and delivery, especially causes of unexpected death such as amniotic fluid embolism.

The role of echocardiography in amniotic fluid embolism: a case series and review of the literature.

PURPOSE: Amniotic fluid embolism (AFE) is a rare, but often fatal condition characterized by sudden hemodynamic instability and coagulopathy occurring during labour or in the early postpartum period. As the mechanisms leading to shock and the cardiovascular effects of AFE are incompletely understood, the purpose of this case series is to describe how AFE presents on echocardiography and review limited reports in the literature. CLINICAL FEATURES: We describe three cases of AFE at the Jewish General Hospital, a tertiary care centre in Montreal, Canada. All cases met the Clark diagnostic criteria, which comprise 1) sudden cardiorespiratory arrest or both hypotension and respiratory compromise, 2) disseminated intravascular coagulation, 3) clinical onset during labour or within 30 min of delivery of the placenta, and 4) absence of fever. Two patients had a cardiac arrest and the third developed significant hypotension and hypoxia. In all patients, point-of-care echocardiography at the time of shock revealed signs of right ventricular failure including a D-shaped septum, acute pulmonary hypertension, and right ventricular systolic dysfunction. CONCLUSION: This case series and literature review of AFE emphasizes the importance of echocardiography in elucidating the etiology of maternal shock. The presence of right ventricular failure may be considered an important criterion to diagnose AFE.

RéSUMé: OBJECTIF: L'embolie de liquide amniotique (ELA) est une complication rare mais souvent fatale caractérisée par une instabilité hémodynamique et une coagulopathie soudaines survenant pendant le travail obstétrical ou au début de la période postpartum. Étant donné que les mécanismes menant au choc et les effets cardiovasculaires de l'ELA ne sont que partiellement compris, le but de cette série de cas était de décrire comment l'ELA apparaît à l'échocardiographie et de passer en revue les rares comptes rendus dans la littérature. CARACTéRISTIQUES CLINIQUES: Nous décrivons trois cas d'ELA survenus à l'Hôpital général juif, un centre tertiaire de soins à Montréal, au Canada. Tous les cas remplissaient les critères diagnostiques de Clark, qui comportent 1) un arrêt cardiorespiratoire soudain ou une hypotension accompagnée d'une détresse respiratoire, 2) une coagulation intravasculaire disséminée, 3) une apparition clinique pendant le travail obstétrical ou dans un délai de 30 minutes suivant la délivrance du placenta, et 4) l'absence de fièvre. Deux patientes ont subi un arrêt cardiaque et le tiers des patientes ont manifesté une hypotension et une hypoxie significatives. Chez toutes les patientes, l'échocardiographie au chevet au moment du choc a révélé des signes d'insuffisance ventriculaire droite, y compris un septum en forme de D, une hypertension pulmonaire aiguë et une dysfonction systolique ventriculaire droite. CONCLUSION: Cette série de cas et revue de littérature de l'ELA souligne l'importance de l'échocardiographie pour élucider l'étiologie du choc maternel. La présence d'une insuffisance ventriculaire droite peut être considérée un critère important pour diagnostiquer une ELA.

Amniotic fluid embolism - implementation of international diagnosis criteria and subsequent pregnancy recurrence risk.

OBJECTIVES: An international diagnostic criterion for amniotic fluid embolism (AFE) diagnosis has recently been published. Data regarding subsequent pregnancies is scarce. We sought to implement recent diagnostic criteria and detail subsequent pregnancies in survivors. METHODS: A case series of all suspected AFE cases at a tertiary medical center between 2003 and 2018 is presented. Cases meeting the diagnostic criteria for AFE were included. Clinical presentation, treatment, and outcomes described. Pregnancy outcomes in subsequent pregnancies in AFE survivors detailed. RESULTS: Between 2003 and 2018 14 women were clinically suspected with AFE and 12 of them (85.71%) met the diagnostic criteria for AFE. Three cases occurred during midtrimester dilation and evacuation procedures, and the remaining occurred in the antepartum period. Of the antepartum cases, mode of delivery was cesarean delivery or vacuum extraction for expedited delivery due to presentation of AFE in 8/9 cases (88.88%). Clinical presentation included cardiovascular collapse, respiratory distress and disseminated intravascular coagulopathy (DIC). Heart failure of varying severity was diagnosed in 75% (9/12) cases. Composite maternal morbidity was 5/12 (41.66%), without cases of maternal mortality. 11 subsequent pregnancies occurred in four AFE survivors. Pregnant women were followed by a high-risk pregnancy specialist and multidisciplinary team if pregnancy continued beyond the early second trimester. Six pregnancies resulted in a term delivery. No recurrences of AFE were documented. CONCLUSIONS: Use of a diagnostic criterion for diagnosis of AFE results in a more precise diagnosis of AFE. Nevertheless, the accuracy of clinical diagnosis is still high. Subsequent pregnancies were not associated with AFE recurrence.