Incidence and risk factors of amniotic fluid embolisms: a population-based study on 3 million births in the United States

Amniotic fluid embolism: an Australian-New Zealand population-based study

Background

Amniotic fluid embolism (AFE) is a major cause of direct maternal mortality in Australia and New Zealand. There has been no national population study of AFE in either country. The aim of this study was to estimate the incidence of amniotic fluid embolism in Australia and New Zealand and to describe risk factors, management, and perinatal outcomes.

Methods

A population-based descriptive study using the Australasian Maternity Outcomes Surveillance System (AMOSS) carried out in 263 eligible sites (>50 births per year) covering an estimated 96 % of women giving birth in Australia and all 24 New Zealand maternity units (100 % of women giving birth in hospitals) between January 1 2010-December 31 2011. A case of AFE was defined either as a clinical diagnosis (acute hypotension or cardiac arrest, acute hypoxia and coagulopathy in the absence of any other potential explanation for the symptoms and signs observed) or as a post mortem diagnosis (presence of fetal squames/debris in the pulmonary circulation).

Results

Thirty-three cases of AFE were reported from an estimated cohort of 613,731women giving birth, with an estimated incidence of 5.4 cases per 100 000 women giving birth (95 % CI 3.5 to 7.2 per 100 000). Two (6 %) events occurred at home whilst 46 % (n = 15) occurred in the birth suite and 46 % (n = 15) in the operating theatre (location not reported in one case). Fourteen women (42 %) underwent either an induction or augmentation of labour and 22 (67 %) underwent a caesarean section. Eight women (24 %) conceived using assisted reproduction technology.

Thirteen (42 %) women required cardiopulmonary resuscitation, 18 % (n = 6) had a hysterectomy and 85 % (n = 28) received a transfusion of blood or blood products. Twenty (61 %) were admitted to an Intensive Care Unit (ICU), eight (24 %) were admitted to a High Dependency Unit (HDU) and seven (21 %) were transferred to another hospital for further management. Five woman died (case fatality rate 15 %) giving an estimated maternal mortality rate due to AFE of 0.8 per 100 000 women giving birth (95 % CI 0.1 % to 1.5 %). There were two deaths among 36 infants.

Conclusions

A coordinated emergency response requiring resource intense multi-disciplinary input is required in the management of women with AFE. Although the case fatality rate is lower than in previously published studies, high rates of hysterectomy, resuscitation, and admission to higher care settings reflect the significant morbidity associated with AFE. Active, ongoing surveillance to document the risk factors and short and long-term outcomes of women and their babies following AFE may be helpful to guide best practice, management, counselling and service planning. A potential link between AFE and assisted reproductive technology warrants further investigation.

Acute respiratory failure in pregnancy

Respiratory failure affects up to 0.2% of pregnancies, more commonly in the postpartum period. Altered maternal respiratory physiology affects the assessment and management of these patients. Respiratory failure may result from pregnancy-specific conditions such as preeclampsia, amniotic fluid embolism or peripartum cardiomyopathy. Pregnancy may increase the risk or severity of other conditions, including thromboembolism, asthma, viral pneumonitis, and gastric acid aspiration. Management during pregnancy is similar to the nonpregnant patient. Endotracheal intubation in pregnancy carries an increased risk, due to airway edema and rapid oxygen desaturation following apnea. Few data are available to direct prolonged mechanical ventilation in pregnancy. Chest wall compliance is reduced, perhaps permitting slightly higher airway pressures. Optimizing oxygenation is important, but data on the use of permissive hypercapnia are limited. Delivery of the fetus does not always improve maternal respiratory function, but should be considered if benefit to the fetus is anticipated.

Successful resuscitation of amniotic fluid embolism applying a new classification and management strategy

Amniotic fluid embolism (AFE) is a rare but life-threatening maternal emergency caused by the entry of amniotic fluid contents into the maternal circulation. The clinical manifestations of AFE are heterogeneous, leading to misdiagnosis or treatment delay. Kanayama and colleagues distinguished the cardiopulmonary collapse type (or classic type) from the disseminated intravascular coagulation (DIC) type of AFE on the basis of the presence of uterine atony and DIC in the latter prior to cardiopulmonary failure. We report a case of DIC-type AFE successfully treated by blood volume replacement and coagulation therapy. The patient was scheduled for elective cesarean delivery because of a previous cesarean section and moyamoya disease. Delivery was uneventful, but massive vaginal bleeding without clotting and ensuing hypovolemic shock occurred 4 h later. She was transferred to the operating room for emergency laparotomy, but sustained a cardiac arrest. The patient was successfully resuscitated and a hysterectomy performed. During surgery, the patient received fresh frozen plasma, platelets, fibrinogen, and antithrombin concentrate. In cardiopulmonary collapse type AFE, cardiopulmonary resuscitation without delay is important. In the present case of DIC-type AFE, however, early supplementation of clotting factors and platelets was critical for patient survival.

Amniotic Fluid Embolism (AFE) in China: Are maternal mortality and morbidity preventable?

A case of hospital-patient conflict has occurred in China that has lifted billows in the public and highlighted the lethality of amniotic fluid embolism (AFE). AFE is a rare but severe obstetric complication with high maternal mortality and morbidity. Globally, the incidence of AFE is estimated to be approximately 2 to 6 per 100,000 deliveries. The maternal mortality rate (MMR) attributable to AFE ranges between 0.5 to 1.7 deaths per 100,000 deliveries in the developed world and 1.9 to 5.9 deaths per 100,000 deliveries in the developing world. In developed countries, AFE often accounts for a leading cause of maternal mortality; whereas the proportion of maternal death caused by AFE tends to be not as dominant compared to common perinatal complications in developing countries. With the mechanism remaining to be elucidated, AFE can neither be predicted nor prevented even in developed countries. Treatment requires a set of highly intensive advanced emergency obstetric care, challenging obstetric care in developing countries. Although this complication is currently far from preventable, China has potential to improve the prognosis of AFE by strengthening the emergency obstetric care system.

Safe prevention of the primary cesarean delivery

In 2011, 1 in 3 women who gave birth in the United States did so by cesarean delivery. Cesarean birth can be lifesaving for the fetus, the mother, or both in certain cases. However, the rapid increase in cesarean birth rates from 1996 through 2011 without clear evidence of concomitant decreases in maternal or neonatal morbidity or mortality raises significant concern that cesarean delivery is overused. Variation in the rates of nulliparous, term, singleton, vertex cesarean births also indicates that clinical practice patterns affect the number of cesarean births performed. The most common indications for primary cesarean delivery include, in order of frequency, labor dystocia, abnormal or indeterminate (formerly, nonreassuring) fetal heart rate tracing, fetal malpresentation, multiple gestation, and suspected fetal macrosomia. Safe reduction of the rate of primary cesarean deliveries will require different approaches for each of these, as well as other, indications. For example, it may be necessary to revisit the definition of labor dystocia because recent data show that contemporary labor progresses at a rate substantially slower than what was historically taught. Additionally, improved and standardized fetal heart rate interpretation and management may have an effect. Increasing women's access to nonmedical interventions during labor, such as continuous labor and delivery support, also has been shown to reduce cesarean birth rates. External cephalic version for breech presentation and a trial of labor for women with twin gestations when the first twin is in cephalic presentation are other of several examples of interventions that can contribute to the safe lowering of the primary cesarean delivery rate.

Amniotic fluid embolism: an interdisciplinary challenge: epidemiology, diagnosis and treatment

BACKGROUND

Amniotic fluid embolism (AFE) is a life-threatening obstetric complication that arises in 2 to 8 of every 100 000 deliveries. With a mortality of 11% to 44%, it is among the leading direct causes of maternal death. This entity is an interdisciplinary challenge because of its presentation with sudden cardiac arrest without any immediately obvious cause, the lack of specific diagnostic tests, the difficulty of establishing the diagnosis and excluding competing diagnoses, and the complex treatment required, including cardio - pulmonary resuscitation.

METHOD

We selectively reviewed pertinent literature published from 2000 to May 2013 that was retrieved by a PubMed search.

RESULTS

The identified risk factors for AFE are maternal age 35 and above (odds ratio [OR] 1.86), Cesarean section (OR 12.4), placenta previa (OR 10.5), and multiple pregnancy (OR 8.5). AFE is diagnosed on clinical grounds after the exclusion of other causes of acute cardiovascular decompensation during delivery, such as pulmonary thromboembolism or myocardial infarction. Its main clinical features are severe hypotension, arrhythmia, cardiac arrest, pulmonary and neurological manifestations, and profuse bleeding because of disseminated intravascular coagulation and/or hyperfibrinolysis. Its treatment requires immediate, optimal interdisciplinary cooperation. Low-level evidence favors treating women suffering from AFE by securing the airway, adequate oxygenation, circulatory support, and correction of hemostatic disturbances. The sudden, unexplained death of a pregnant woman necessitates a forensic autopsy. The histological or immunohistochemical demonstration of formed amniotic fluid components in the pulmonary bloodflow establishes the diagnosis of AFE.

CONCLUSION

AFE has become more common in recent years, for unclear reasons. Rapid diagnosis and immediate interdisciplinary treatment are essential for a good outcome. Establishing evidence-based recommendations for intervention is an important goal for the near future.

Amniotic fluid embolism: the known and not known

Amniotic fluid embolism was first recognized in 1926, in a Brazilian journal case report, on the basis of large amounts of fetal material in the maternal pulmonary vasculature at autopsy. The first English language description appeared in 1941 and consisted of eight parturients dying suddenly in which, once again, fetal material was seen in the pulmonary vasculature. A control group of 34 pregnant women dying of other recognized causes did not have fetal material in their lungs. The incidence of recognized, serious illness is on the order of two to eight per 100,000, with a mortality rate ranging from 13% to 35%. The diagnosis rests largely on one or more of four clinical signs: circulatory collapse, respiratory distress, coagulopathy, and seizures/ coma. The only confirmatory laboratory test remains autopsy findings although serum tests for fetal antigen, insulin-like growth factor binding protein-1, and complement are currently being investigated. One of the paradoxes of diagnosis is that fetal material in the pulmonary circulation at autopsy is specific for amniotic fluid embolism, while the same finding in the living is not. The mechanism of disease remains uncertain although the best available evidence suggests that complement activation might have a role. In contrast, mast cell degranulation probably is not a mechanism, so amniotic fluid embolism is not an anaphylaxis or anaphylactoid reaction as has been occasionally suggested. Perhaps the greatest unknown is not why 1 in 50,000 pregnant women develop what appears to be an immune response to their fetus, but rather why the other 49,999 do not?

Amniotic fluid embolism--investigation of fatal cases in Slovakia in the years 2005-2010 compared with fatal cases in the United Kingdom

BACKGROUND

Amniotic fluid embolism (AFE) is a rare, often severe complication of pregnancy. The clinical diagnosis is difficult to establish and is one of exclusion. The aim of this study was to investigate 6 fatal cases of AFE in Slovakia and compare the incidence, risk factors, course, management and neonatal outcomes with fatal cases of AFE in the United Kingdom (UK).

MATERIALS AND METHODS

Data on fatal cases of AFE in Slovakia were analysed and compared with fatal cases in the UK in the years 2005-2010.

RESULTS

The incidence in Slovakia was significantly higher than in the UK from 2005-2010 (RR 5.03, 95% CI 1.98-12.75, P=0.003). However, 5/6 deaths occurred in 2009 coinciding with the H1N1 flu virus pandemic in Slovakia. There were no significant differences in the characteristics of women who died, with the exception of gestational age at delivery; significantly higher in Slovakia (median 41 versus 39 weeks, P=0.01). In Slovakia most of the cases occurred after delivery, 83.3%, compared with 52.9% in the UK. There were no significant differences in clinical signs, use of recombinant factor VIIa or performance of obstetric hysterectomy. In Slovakia 83.3% and in the UK 94.7% of infants survived, but 20% and 27.8% had some long-term sequelae.

CONCLUSION

AFE is now the leading cause of maternal deaths in Slovakia. However, we found no significant differences in the possible risk factors, course, management or outcomes between Slovakia and the UK. This analysis is limited by study power; we propose that establishment of a national register of cases of AFE in Slovakia would help further investigate and monitor mortality from this condition.

Pulmonary embolism and amniotic fluid embolism in pregnancy

Amniotic fluid embolism and pulmonary embolism are 2 of the most common causes of maternal mortality in the developed world. Symptoms of pulmonary embolism include tachycardia, tachypnea, and shortness of breath, all of which are common complaints in pregnancy. Heightened awareness leads to rapid diagnosis and institution of therapy. Amniotic fluid embolism is associated with maternal collapse. There are currently no proven therapies, although rapid initiation of supportive care may decrease the risk of mortality.

Incidence, risk factors, and consequences of amniotic fluid embolism

BACKGROUND

Amniotic fluid embolism (AFE) is a rare but serious cause of maternal mortality whose aetiology remains obscure. Previous population-based studies have reported associations with labour induction and caesarean delivery.

METHODS

We updated a previous analysis based on the US Nationwide Inpatient Sample from 1999 to 2008. We adapted a diagnostic validation algorithm to minimise false-positive diagnoses, along with statistical methods that account for the stratified random sampling design.

RESULTS

Of the 8 571 209 deliveries recorded in the database, 276 met our case definition of AFE, of which 62 (22.9% of the 274 with known vital status) were fatal. Significant associations with AFE were observed for medical induction {adjusted odds ratio [aOR] = 1.7 [95% confidence interval (CI) 1.2, 2.5]}, caesarean delivery [aOR = 15.0; 95% CI 9.4, 23.9], instrumental vaginal delivery [aOR = 6.6; 95% CI 4.0, 11.1], and cervical/uterine trauma [aOR = 7.4; 95% CI 3.6, 14.9]. AFE was associated with increases in risk of stillbirth, hysterectomy, maternal death, and prolonged maternal length of delivery hospital stay.

CONCLUSIONS

AFE remains an extremely serious obstetric complication with high risks of maternal and fetal mortality. The increased risks of AFE associated with labour induction and caesarean delivery have implications for elective use of these interventions.

The use of therapeutic hypothermia in the management of amniotic fluid embolism

Background:

Amniotic fluid embolism (AFE) is a rare peripartum obstetric emergency where patients seldom survive neurologically intact. The exact pathophysiology is not completely understood and treatment remains mainly supportive.

Case:

A 34-year-old African American woman gravida 1, para 0-0-0-0 at 38 weeks and four days induced for chronic hypertension with superimposed preeclampsia experienced an AFE during labour. Supportive treatment included early use of therapeutic hypothermia resulting in a normal neurological outcome.

Conclusion:

This case demonstrates the timely use of therapeutic hypothermia in a patient surviving an AFE and suffering no neurological sequelae. Therapeutic hypothermia should be considered in the supportive treatment of AFE.

Amniotic fluid embolism: 10-year retrospective study in a level III maternity hospital

OBJECTIVE

To provide updated data on amniotic fluid embolism (AFE) based on our population over a 10 year period, and to propose steps for improving current practice.

STUDY DESIGN

Retrospective study carried out in the Department of Gynaecology and Obstetrics at the Strasbourg University Teaching Hospital between 1 January 2000 and 31 December 2010. Dossiers of patients with AFE were identified using medical information system programme (MISP) coding and cross-checked with the pathology reports (hysterectomy, post-mortem examination).

RESULTS

Eleven dossiers were found (0.28/1000). Eight cases (73%) of AFE occurred during labour, two (18%) in the post-partum period and one (9%) outside of parturition. Induction was initiated in four patients (45%) and labour sustained with oxytocin in 9 patients (90%). Acute circulatory collapse with cardio-respiratory arrest (CRA) was the herald symptom of AFE in 2 patients, and secondary cardio-respiratory arrest occurred rapidly in 6 patients (55%) following a relatively non-indicative prodromal phase. Disseminated intravascular coagulopathy (DIC) was observed in 10 cases (91%) and massive transfusion was necessary in all patients. Seven haemostatic hysterectomies (63%) were performed, with secondary arterial embolisation in 2 cases (22%). Although all patients presented a clinical picture of AFE, confirmation through histology or laboratory test results was forthcoming in only 7 cases (63%). Three patients died (27%). When AFE occurred during labour, 8 fetuses (75%) received intensive care support. In all, 11 newborns survived (85%). Their pH was less than 7.00 in 3 cases (27%) and 4 fetuses (36%) had an Apgar score of less than 5 at 5 minutes of life.

CONCLUSION

AFE is a rare but extremely serious disease. Some risk factors for AFE have been identified but they do not allow its occurrence to be predicted. The diagnosis may be supported by specific laboratory test results but only a post-mortem examination provides a pathognomonic diagnosis: unfortunately it is always retrospective. Obstetrical and intensive care management is complex and must be adapted to the situation bearing in mind the significant risk of haemorrhage and DIC. Hysterectomy must be performed if there is the least doubt.

[Amniotic fluid embolism: an update]

Amniotic fluid embolism (AFE) results from the passage of fœtal and amniotic fragments into the maternal circulation, occurring mostly within minutes before or after delivery. Although maternal and fœtal mortality of AFE remains high (about 40%), AFE should no longer be considered as having an ineluctable fatal course. Diagnosis is often made upon clinical presentation but histological confirmation is difficult owing favorable outcome and because an autopsy has not been performed. Identification of squamous cells in the maternal circulation could not confirm the diagnosis because of their possible maternal origin. High plasma level of insulin-like growth factor-binding protein-1 (IGFBP-1) has recently been identified as a biomarker of amniotic fluid passage into the maternal circulation and might therefore be used to confirm the diagnosis when lung tissue histology is not available. Treatment of AFE remains supportive with a special focus on correction of the coagulopathy and search for acute core pulmonale. In this later case, physicians should consider initiating an extracorporeal life support when facing a patient with refractory shock. Finally, caution is needed with the use of recombinant factor VIIa in this context.

Fatal amniotic fluid embolism with typical pathohistological, histochemical and clinical features

Despite the decrease in maternal mortality rate, amniotic fluid embolism (AFE) is still one of the most feared complications of pregnancy due to the high rate of mortality in Japan. The authors present a fatal case of a healthy 39-year-old woman who died during delivery after a normal 40-week second pregnancy. Shortly after the arrival at hospital, an abrupt drop of foetal heart rate was observed, followed by deterioration of consciousness and cardiac arrest of the patient. Prompt cardiopulmonary resuscitation (CPR) was performed but the patient died about an hour and a half after her arrival at hospital. Forensic autopsy confirmed the pathohistological diagnosis of amniotic fluid embolism supported by histochemical analysis results and excluded other possible causes of death. This paper stresses the fundamental importance of autopsy in an unexpected maternal death in conjunction with the significance of data accumulation on maternal death.

Complications in late pregnancy

Complications of late pregnancy are managed infrequently in the emergency department and, thus, can pose a challenge when the emergency physician encounters acute presentations. An expert understanding of the anatomic and physiologic changes and possible complications of late pregnancy is vital to ensure proper evaluation and care for both mother and fetus. This article focuses on the late pregnancy issues that the emergency physician will face, from the bleeding and instability of abruptio placentae to the wide spectrum of complications and management strategies encountered with preterm labor.

Postpartum hemorrhage: when uterotonics and sutures fail

Systemic bleeding at the time of postpartum hemorrhage (PPH) is usually the result of coagulopathy that has developed acutely as a result of massive hemorrhage after uterotonics and sutures have failed. Occasionally, the patient has a preexisting coagulopathy, but more often, coagulopathy arises acutely as the result of massive hemorrhage, which is usually related to obstetrical and less often surgical bleeding. Despite being able to identify risk factors for PPH in the antenatal and intrapartum period, the majority of women who ultimately develop PPH do not have any such factors and every pregnancy is at risk. The coagulopathy associated with massive PPH may be due to hemodilution, failure of liver synthetic function as occurs with acute liver failure of pregnancy, or disseminated intravascular coagulation (DIC). There are no data from clinical trials to help guide management of transfusion in PPH, although the management of blood component therapy in severe PPH is similar to that in other massive hemorrhage. Standard practice is to replace fibrinogen to maintain a level of ≥ 100 mg/dL, yet recent evidence suggests that the level of fibrinogen needed to prevent PPH is at least 400 mg/dL. Recombinant activated factor VIIa (rFVIIa) has been used in the management of severe PPH unresponsive to blood component therapy. Coagulation laboratory evaluation may be useful in guiding hemostatic management during massive PPH, but for the results to be useful, they must be rapidly available and provide information that would not be available from clinical assessment alone. The hematologist or hemostasis expert has the opportunity to make the difference between life and death for the patient experiencing massive PPH.

Amniotic fluid embolism incidence, risk factors and outcomes: a review and recommendations

BACKGROUND

Amniotic fluid embolism (AFE) is a rare but severe complication of pregnancy. A recent systematic review highlighted apparent differences in the incidence, with studies estimating the incidence of AFE to be more than three times higher in North America than Europe. The aim of this study was to examine population-based regional or national data from five high-resource countries in order to investigate incidence, risk factors and outcomes of AFE and to investigate whether any variation identified could be ascribed to methodological differences between the studies.

METHODS

We reviewed available data sources on the incidence of AFE in Australia, Canada, the Netherlands, the United Kingdom and the USA. Where information was available, the risk factors and outcomes of AFE were examined.

RESULTS

The reported incidence of AFE ranged from 1.9 cases per 100 000 maternities (UK) to 6.1 per 100 000 maternities (Australia). There was a clear distinction between rates estimated using different methodologies. The lowest estimated incidence rates were obtained through validated case identification (range 1.9-2.5 cases per 100 000 maternities); rates obtained from retrospective analysis of population discharge databases were significantly higher (range 5.5-6.1 per 100 000 admissions with delivery diagnosis). Older maternal age and induction of labour were consistently associated with AFE.

CONCLUSIONS

Recommendation 1: Comparisons of AFE incidence estimates should be restricted to studies using similar methodology. The recommended approaches would be either population-based database studies using additional criteria to exclude false positive cases, or tailored data collection using existing specific population-based systems.Recommendation 2: Comparisons of AFE incidence between and within countries would be facilitated by development of an agreed case definition and an agreed set of criteria to minimise inclusion of false positive cases for database studies.Recommendation 3: Groups conducting detailed population-based studies on AFE should develop an agreed strategy to allow combined analysis of data obtained using consistent methodologies in order to identify potentially modifiable risk factors.Recommendation 4: Future specific studies on AFE should aim to collect information on management and longer-term outcomes for both mothers and infants in order to guide best practice, counselling and service planning.

Amniotic fluid embolism incidence, risk factors and outcomes: a review and recommendations

BACKGROUND

Amniotic fluid embolism (AFE) is a rare but severe complication of pregnancy. A recent systematic review highlighted apparent differences in the incidence, with studies estimating the incidence of AFE to be more than three times higher in North America than Europe. The aim of this study was to examine population-based regional or national data from five high-resource countries in order to investigate incidence, risk factors and outcomes of AFE and to investigate whether any variation identified could be ascribed to methodological differences between the studies.

METHODS

We reviewed available data sources on the incidence of AFE in Australia, Canada, the Netherlands, the United Kingdom and the USA. Where information was available, the risk factors and outcomes of AFE were examined.

RESULTS

The reported incidence of AFE ranged from 1.9 cases per 100 000 maternities (UK) to 6.1 per 100 000 maternities (Australia). There was a clear distinction between rates estimated using different methodologies. The lowest estimated incidence rates were obtained through validated case identification (range 1.9-2.5 cases per 100 000 maternities); rates obtained from retrospective analysis of population discharge databases were significantly higher (range 5.5-6.1 per 100 000 admissions with delivery diagnosis). Older maternal age and induction of labour were consistently associated with AFE.

CONCLUSIONS

Recommendation 1: Comparisons of AFE incidence estimates should be restricted to studies using similar methodology. The recommended approaches would be either population-based database studies using additional criteria to exclude false positive cases, or tailored data collection using existing specific population-based systems.Recommendation 2: Comparisons of AFE incidence between and within countries would be facilitated by development of an agreed case definition and an agreed set of criteria to minimise inclusion of false positive cases for database studies.Recommendation 3: Groups conducting detailed population-based studies on AFE should develop an agreed strategy to allow combined analysis of data obtained using consistent methodologies in order to identify potentially modifiable risk factors.Recommendation 4: Future specific studies on AFE should aim to collect information on management and longer-term outcomes for both mothers and infants in order to guide best practice, counselling and service planning.

Perinatal morbidity and risk of hypoxic-ischemic encephalopathy associated with intrapartum sentinel events

OBJECTIVE

To examine perinatal morbidity and rate of hypoxic-ischemic encephalopathy in infants exposed to intrapartum sentinel events.

STUDY DESIGN

Retrospective cohort study from 2000-2005. Perinatal mortality, perinatal morbidity and rate of hypoxic-ischemic encephalopathy were compared in 3 groups of infants exposed to different risk factors for perinatal asphyxia (sentinel events, nonreassuring fetal status, elective cesarean section).

RESULTS

Five hundred eighty-six infants were studied. Perinatal mortality was 6% in the sentinel event group and 0.3% in the nonreassuring fetal status group (relative risk, 2.4; 95% confidence interval, 1.95-2.94). Perinatal morbidity was 2-6 times more frequent in infants exposed to sentinel events; the incidence of hypoxic-ischemic encephalopathy was 10%, compared with 2.5% in the nonreassuring fetal status group (relative risk, 1.93; 95% confidence interval, 1.49-2.52). No infant in the elective cesarean section group died, had perinatal morbidity, or developed encephalopathy.

CONCLUSION

Intrapartum sentinel events are associated with a high incidence of perinatal morbidity and hypoxic-ischemic encephalopathy.

Obstetric hemorrhage

An obstetric hemorrhage may occur before or after delivery, but more than 80% of cases occur postpartum. Worldwide, a massive obstetric hemorrhage, resulting from the failure of normal obstetrical, surgical and/or systemic hemostasis, is responsible for 25% of the estimated 358,000 maternal deaths each year. Most women will not have identifiable risk factors. Nonetheless, primary prevention of a postpartum hemorrhage (PPH) begins with an assessment of identifiable risk factors. Women identified as being at high risk of a PPH should be delivered in a center with access to adequately trained staff and an onsite blood bank. A critical feature of a massive hemorrhage in obstetrics is the development of disseminated intravascular coagulation (DIC), which, in contrast to DIC that develops with hemorrhage from surgery or trauma, is frequently an early feature. Data from clinical trials to guide management of transfusion in PPH are lacking. There are likely to be similarities in the management of transfusion in severe PPH to that of major bleeding in other clinical situations, but the pathophysiological processes that contribute to a massive PPH may necessitate different transfusion strategies such as the ratio of red blood cells to plasma components, in particular fibrinogen. Caution should be exercised when considering the appropriate place for recombinant activated factor VII (rFVIIa) in the management of a major PPH. An early hysterectomy is recommended for severe bleeding as a result of placenta accreta or uterine rupture. However, in women with uterine atony who have ongoing bleeding in spite of an adequate transfusion, it may be reasonable to consider a trial of rFVIIa before a hysterectomy.

Amniotic fluid embolism: A diagnostic dilemma

Amniotic fluid embolism (AFE) is a rare obstetric catastrophe with an incidence of 7.7 per 100 000 deliveries and mortality as high as 60% to 80%. We describe a case of perioperative cardiac arrest in a young parturient undergoing an emergent cesarean section. Just after delivery of live healthy male baby, patient developed disseminated intravascular coagulation not responding to resuscitation with fluids and blood products. Her autopsy revealed edematous lungs with amniotic fluid debris within pulmonary vessels thus establishing the diagnosis of AFE. Amniotic fluid embolism is life threatening and difficult to predict or prevent condition, which should be always be kept in mind in a parturient with sudden cardiovascular collapse, so that resuscitation commences immediately, as early intervention is essential for a positive outcome.

Amniotic fluid embolism that took place during an emergent Cesarean section -A case report-

Amniotic fluid embolism (AFE) is a rare but fatal obstetric emergency, characterized by sudden cardiovascular collapse, dyspnea or respiratory arrest and altered mentality, disseminated intravascular coagulation (DIC). It can lead to severe maternal morbidity and mortality, but the prediction of its occurrence and treatment are very difficult. We experienced a case of AFE during emergent Cesarean section in a 40⁺⁶ weeks healthy pregnant woman, age 33. Sudden dyspnea, hypotension, signs of pulmonary edema and DIC were developed during Cesarean section, and cardiac arrest followed after these events. The course of these events was so rapid and catastrophic, which was consistent with AFE. Thus, we report this case precisely and review pathophysiology, diagnosis, treatment of AFE by referring to up-to-date literatures.

Amniotic fluid embolism

Amniotic fluid embolism (AFE) remains an enigmatic, but devastating obstetrical condition associated with significant maternal and newborn morbidity and mortality. Although our understanding of this condition is incomplete, research over the past 2 decades has altered traditional concepts of both the causation and pathophysiology of AFE. Although maternal treatment remains primarily supportive, prompt delivery of the fetus can substantially improve neonatal outcome after AFE-induced cardiac arrest. Newer biochemical markers may in the future enhance the specificity and sensitivity of this clinical diagnosis and could potentially lead to improved therapy.