What is Amniotic Fluid Embolism?

Amniotic fluid embolism (AFE) is a dangerous and life-threatening complication that occurs during or shortly after delivery. Amniotic fluid embolism is very difficult to diagnose because the symptoms can be similar to other severe complications during childbirth.

This complication is rare but serious. It happens when fetal cells or amniotic fluid, which is the fluid that surrounds the fetus in the womb during pregnancy, enter the parent’s bloodstream.

What is amniotic fluid embolism?

Amniotic fluid embolism (AFE) is a rare, life-threatening complication that occurs when a pregnant person gets amniotic fluid into their bloodstream just before, during, or immediately after delivery.

Amniotic fluid surrounds the fetus in the womb during pregnancy. It is mainly made of water but also contains embryonic cells and tissue. For reasons that are mostly unknown, some people have a severe allergic reaction to amniotic fluid mixing with their blood.

Amniotic fluid embolism can lead to heart and lung failure, which causes many complications due to the lack of oxygenated blood in the body; this can include cardiac arrest. People with AFE may bleed uncontrollably from their uterus or cesarean section. AFE occurs suddenly and is unpredictable. Its treatment is very challenging and requires emergency medical care.

Amniotic fluid entering the bloodstream is a natural part of the birth process. In most people, it does not cause an allergic reaction. Researchers are still determining why some people react to amniotic fluid this way while others don’t. AFE is also known as anaphylactic syndrome of pregnancy.

Symptoms

The first stage of AFE usually causes cardiac arrest and rapid respiratory failure. Cardiac arrest occurs when the heart stops working, loses consciousness, and stops breathing.

Acute respiratory failure occurs when the lungs cannot deliver enough oxygen to the blood or remove enough carbon dioxide. This makes breathing very difficult. Other possible symptoms include:

Fetal distress
Change in skin color
Vomit
Nausea
Convulsions
Severe anxiety, restlessness

Women who survive these events may enter a second phase called the hemorrhagic phase. This happens when there is excessive bleeding at the placental junction or, in the case of cesarean delivery, at the site of the cesarean incision.

What causes amniotic fluid embolism?

Amniotic fluid embolism is a rare and sudden disease. The exact cause is unknown. Between 1 and 12 cases of amniotic fluid emboli occur per 100,000 births.

Amniotic fluid embolism can occur in healthy pregnant women during the second trimester, standard delivery, cesarean section, or up to forty-eight hours after abnormal delivery. In some cases, it occurs after a woman’s abortion through an intrauterine injection.

Because the disease is so rare, it is difficult to determine the exact risk factors for its development, but it may include:

Age: Women aged 35 or older at the time of delivery may be at increased risk of amniotic fluid embolism.
Cesarean delivery: Procedures such as cesarean section, forceps delivery, or vacuum suction disrupt the barriers between mother and baby.
Induced labor: Some methods used to induce labor may increase the risk of amniotic fluid embolism, but research on this is still limited.
Placental Abnormalities: If the placenta partially or completely covers the cervix or detaches from the uterine wall during delivery, this disrupts the barrier between mother and baby.
Preeclampsia: This is a complication that is diagnosed in the final stages of pregnancy, in which the woman has high blood pressure, protein in the urine, and swelling of the hands and feet.
Polyhydramnios: This is a condition in which a woman has too much amniotic fluid around her baby.

Risk factors

Risk factors for AFE are difficult to predict because they are rare and difficult to study. However, current research points to several possible risk factors, including:

Having a C-section delivery
Operative assisted deliveries
Preeclampsia or eclampsia
Polyhydramnios
Cervical tears
Labor induction medications or procedures
Advanced maternal age
Expecting multiples
Fetal distress
Issues with the placenta, like placental abruption

How serious is it?

AFE can be fatal, especially in the first stage. Most AFE deaths occur due to:

Sudden cardiac arrest
Excessive blood loss
Acute respiratory distress
Multiple organ failure

According to the AFE Foundation, in approximately 50 percent of cases, women die within 1 hour of the onset of symptoms.

How do doctors detect amniotic fluid embolism?

Detecting amniotic fluid embolism (AFE) can be challenging because it is a rare and rapidly progressing condition with no specific diagnostic test. However, doctors typically rely on a combination of clinical signs, symptoms, and diagnostic tests to make a diagnosis. Here are some key approaches used in the detection of AFE.

Clinical presentation

Doctors assess the mother’s symptoms and medical history, especially during labor, delivery, or immediately postpartum. A sudden onset of respiratory distress, cardiovascular collapse, seizures, or altered mental status in a woman who has recently given birth may raise suspicion for AFE.

Physical examination

Doctors perform a thorough physical examination to assess vital signs, including blood pressure, heart rate, respiratory rate, and oxygen saturation. Signs such as hypotension, tachycardia, hypoxia, and cyanosis may suggest AFE.

Laboratory tests

Blood tests evaluate signs of coagulopathy (abnormal blood clotting), such as prolonged clotting times, decreased platelet count, and evidence of fibrinolysis. Abnormalities in blood gas analysis, such as metabolic acidosis and hypoxemia, may also be present.

Imaging studies

A chest X-ray or computed tomography (CT) scan may be performed to evaluate for pulmonary edema, pulmonary embolism, or other lung abnormalities associated with AFE. However, these findings are nonspecific and may overlap with other conditions.

Echocardiography

Transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE) may assess cardiac function and detect signs of right heart strain or pulmonary hypertension, which can occur in AFE-induced cardiovascular collapse.

Exclusion of other conditions

Doctors may need to rule out other potential causes of acute maternal deterioration, such as pulmonary embolism, eclampsia, sepsis, hemorrhage, or allergic/anaphylactic reactions.

Given the rapid progression and severity of AFE, early recognition and prompt intervention are critical for improving maternal outcomes. Treatment is initiated based on clinical suspicion, and definitive confirmation of AFE may only be possible after delivery through postmortem examination or examination of tissue samples.

Treatment

The treatment of amniotic fluid embolism (AFE) involves prompt recognition of the condition and immediate supportive care to stabilize the mother and manage complications.

Supportive measures

The primary goal of treatment is to support vital functions and prevent further deterioration. This includes ensuring adequate oxygenation through supplemental oxygen therapy and mechanical ventilation if necessary. Intravenous fluids are administered to maintain blood pressure and cardiac output.

Hemodynamic support

Medications may be given to support blood pressure and cardiac function.

Correction of coagulopathy

AFE can lead to disseminated intravascular coagulation (DIC), characterized by abnormal blood clotting and bleeding. Blood products, such as fresh frozen plasma, platelets, and cryoprecipitate, may be transfused to correct coagulopathy and replenish clotting factors.

Monitoring and management of complications

Patients with AFE are closely monitored for complications such as seizures, pulmonary edema, acute respiratory distress syndrome (ARDS), and multiorgan dysfunction. Treatment is provided based on the specific complications that arise. For example, anticonvulsant medications may be administered to control seizures, and diuretics may be used to manage pulmonary edema.

Delivery of the fetus

In cases where AFE occurs during labor or delivery, expedited delivery of the fetus may be necessary to minimize maternal morbidity and mortality. This may involve assisted vaginal delivery or emergency cesarean section.

Critical care support

Patients with severe AFE may require admission to an intensive care unit (ICU) for close monitoring and advanced life support. In some cases, extracorporeal membrane oxygenation (ECMO) may be considered a supportive measure for refractory respiratory or cardiovascular failure.

Psychological support

AFE is a traumatic event for both the mother and her family. Psychological support and counseling may be provided to help the patient and her loved one cope with the experience’s emotional impact.

It’s important to note that despite aggressive treatment, the mortality rate associated with AFE remains high. Therefore, early recognition, rapid intervention, and multidisciplinary care involving obstetricians, intensivists, anesthesiologists, hematologists, and other specialists are crucial in improving maternal outcomes.

The bottom line

AFE is a rare but severe disease. It occurs when amniotic fluid or fetal cells enter the parent’s bloodstream and cause a blockage. There is no known way to prevent this condition, but risk factors include older age, multiple pregnancies, and cesarean delivery.

AFE is considered an emergency, so people with symptoms need immediate medical attention. If you are pregnant, your chances of developing AFE are very low. Discuss your concerns about this rare condition with your pregnancy care provider so they can help ease your worries.

Additional questions

What can be done to prevent amniotic fluid embolism?

Preventing AFE is challenging because the exact cause of this rare condition is not fully understood. However, several strategies can potentially reduce the risk or mitigate the severity of AFE:

Prenatal Care
High-Risk Pregnancy Management
Intrapartum Monitoring
Emergency Preparedness
Timely Cesarean Delivery
Minimize Trauma
Education and Awareness
Research and Surveillance

What are the long-term effects for women who survive amniotic fluid embolism?

Many survivors of amniotic fluid embolism experience long-term or lifelong complications that vary in severity. Complications vary greatly depending on each person’s response to amniotic fluid embolism, health history, and genetic predisposition to other diseases.

Does amniotic fluid embolism affect the fetus?

Babies born before any symptoms are often healthy and unlikely to suffer long-term health problems associated with amniotic fluid embolism. Babies who are born after the onset of symptoms in the mother may have an emergency delivery. They risk reduced oxygenation and require immediate and aggressive critical care interventions. .

What is the survival rate for women who experience amniotic fluid embolism?

Amniotic fluid embolism survival depends on many factors; therefore, providing an accurate rate is very difficult. These factors include diversity of each woman’s immune response

Place of birth
Type of hospital and level of service
Event time (before or after delivery)
Urgent recognition and aggressive treatment
Previous health problems or the presence of other maternal health conditions

Published rates from studies could be more consistent and vary depending on how and when data were collected. Published survival rates range from 20 to 60 percent.

What is the most common cause of maternal death immediately after childbirth?

During pregnancy, bleeding and cardiovascular diseases are the leading causes of death. At birth and shortly after that, infection is the main cause.

References

https://my.clevelandclinic.org/health/diseases/15463-amniotic-fluid-embolism

https://afesupport.org/what-is-amniotic-fluid-embolism/

https://www.healthline.com/health/pregnancy/amniotic-fluid-embolism

https://www.webmd.com/baby/what-is-amniotic-fluid-embolism

https://www.medicalnewstoday.com/articles/amniotic-fluid-embolism#summary