Amniotic fluid embolism is a rare, life threatening, and often fatal complication of pregnancy.
Read on to find out more about it, and why it happens.
What is amniotic fluid embolism?
Normally during pregnancy, amniotic fluid (which includes material such as fetal cells and hair) stays within the uterus, sealed inside the amniotic sac.
Amniotic fluid embolism (AFE) occurs when there is a breakdown between the amniotic fluid and the maternal blood circulation. This allows the amniotic fluid and fetal material to enter the mother’s bloodstream and lungs.
What happens in an amniotic fluid embolism?
It’s thought the most likely cause is a breakdown in the placental barrier. The mother’s immune system responds by releasing inflammatory products that activate abnormal clotting in the lungs and blood vessels.
This quickly results in a blood clotting disorder called disseminated intravascular coagulation.
Recent research has suggested amniotic embolism is the result of allergy to fetal antigens, which triggers an allergic reaction.
The reaction is similar to what happens in anaphylaxis, in cases of insect or food allergies, where breathing can be restricted.
You might sometimes see AFE referred to as anaphylactoid syndrome of pregnancy.
What causes an amniotic fluid embolism?
Interventions like induction of labour, c-section, forceps deliveries, epidural and vacuum extraction increase your chances of having AFE, as these procedures disrupt the physical barriers between you and your baby.
It’s always a good idea to minimise intervention in your pregnancy, labour, and birth, so as not to interrupt the natural rhythm of your body.
AFE can happen in healthy women during labour or shortly after giving birth, and in both vaginal and c-section births. It can also occur during a pregnancy termination or when an amniocentesis is performed.
You can find more information in The Cascade Of Intervention – What You Need To Know | BellyBelly
Amniotic fluid embolism symptoms
There are two phases of amniotic fluid embolism.
During the first phase, the mother might begin to experience shortness of breath and have a sudden drop in blood pressure (hypotension).
Cardiac arrest can follow quickly, and many women will fall into a coma within minutes. About 60-80% of women don’t survive the first stage of amniotic fluid embolism.
Women who do survive the first phase will enter the second phase of AFE – the haemorrhagic phase.
Signs and symptoms include:
- Severe shortness of breath
- Fetal distress
- Excessive bleeding, due to disseminated intravascular coagulation (DIC). DIC prevents blood clotting by decreasing the clotting factors.
When can amniotic fluid embolism occur?
The worrying thing about amniotic fluid embolism is it can occur in healthy women.
It can happen:
- During surgical abortion
- In the second trimester of pregnancy
- During normal labour
- During a c-section
- After an abnormal vaginal birth (such as an induction, or forceps birth)
- Up to 48 hours after birth
- After abdominal trauma
- During amnio-infusion.
Amniotic fluid embolism risk factors
A review of evidence-based research has shown there are several risk factors for amniotic fluid embolism, including:
- Maternal age of 35 years or older at the time of the child’s birth
- Having preeclampsia (high blood pressure with excess protein in the urine after 20 weeks of pregnancy)
- Placenta previa (placenta covering the cervix) or placental abruption (placenta coming away from the uterus wall before birth).
- Induction before labour begins spontaneously.
- Having an operative birth, including c-section, forceps or vacuum birth
- Having polyhydramnios (too much amniotic fluid)
- Cervical lacerations (tearing of the cervix)
- Uterine rupture (a tear in the uterus wall).
The incidence of AFE is reported to range from 1 in 8,000 to 1 in 80,000 pregnancies.
Can you prevent an amniotic fluid embolism?
The truly frightening aspect of amniotic fluid embolism is there are no warning signs and no known prevention.
Avoiding intervention in pregnancy, labour and birth decrease your chances of amniotic fluid embolism. However, it has to be noted AFE can occur even with no intervention.
Although an amniotic fluid embolism can’t be prevented, it’s important to remember it’s extremely rare.
If you’ve experienced AFE and plan on future pregnancies, discuss your options with an obstetrician beforehand and check out the AFE Foundation.
Amniotic fluid embolism complications
If left untreated, amniotic fluid embolism can lead to disseminated intravascular coagulation (DIC).
DIC causes blood clots to form throughout the body and blocks small blood vessels, resulting in:
- Chest pain
- Shortness of breath
- Leg pain
- Problems in moving parts of the body, or speaking.
These blood clots essentially use up the body’s clotting factors and can lead to extensive bleeding in other areas, causing organ failure and respiratory failure. This is life-threatening to mother and baby.
Diagnosis of amniotic fluid embolisms
There are no tests to diagnose AFE when it occurs, so care providers must rely on the following symptoms to make a diagnosis:
- Acute respiratory problems – breathing is really difficult and can result in respiratory failure
- Low blood oxygen
- Choking, coughing
- Turning blue
- Sudden onset of severe chest pain
- Sudden drop in blood pressure, or cardiac arrest, because of the increased pressure on the heart
- Severe loss of blood from various body sites.
If all of the above symptoms occur during labour, cesarean section, dilation, and evacuation, or within 30 minutes of birth with no other explanation, doctors will make a diagnosis of AFE.
Sometimes, unfortunately, the only way to make a definitive diagnosis of AFE is post mortem, by examining the maternal fetal squamous cells and blood vessels.
Amniotic fluid embolism treatment
If AFE is diagnosed, the mother’s treatment must begin immediately, and consists of:
- Oxygen therapy, usually via a ventilator
- Large volumes of intravenous fluids
- CPR, if cardiac arrest occurs
- C-section (if the baby hasn’t already been born), performed within five minutes, or as soon as possible, after cardiac arrest
- Medications that might be needed to control blood pressure and help the heart rate
- Blood transfusions, to replace the blood lost during the hemorrhagic phase.
The baby is monitored for signs of fetal distress, such as changed heart rate, and will be born as soon as possible once the mother is in a stable condition. This increases the chances of survival for the baby.
If you have risk factors going into your birth, or you’ve had an amniotic fluid embolism in previous deliveries, the obstetrics and gynecology team might have these medications ready to go, for a quick response:
- Uterotonics. Oxytocin, F2Alpha and Carboprost help reduce bleeding from the uterus
- Corticosteroids. Hydrocortisone assists with immune response, as amniotic fluid embolism can be like an anaphylactic reaction to the body and affects the immune system
- Intravenous fluid replacement therapy, which helps to replace fluid volume loss
- Blood transfusion, to replace blood loss
- Oxygen, to assist the circulatory system and improve condition (oxygen is classed as a medication in the hospital system)
- Sometimes plasma is required.
Amniotic fluid embolism survivors
Over 30 years ago, the maternal mortality rate for AFE was almost 90%.
Better resuscitation techniques, intensive care facilities, and early recognition of amniotic fluid embolisms have decreased mortality rates for women and babies.
AFE accounts for 4.7% of direct maternal deaths in the UK, 13% in France, 30% in Singapore, and around 10% in the United States. Babies who are alive at the time of AFE occurring have a 70% chance of survival.
The majority of women survive, but around 80% go on to have long-term brain and organ damage. Around 50% of babies who survive experience some form of nervous system damage or cerebral palsy.
Fortunately, amniotic fluid embolism is a rare complication of pregnancy and birth. It cannot be prevented and it is difficult to predict if and when AFE will occur.
If you have experienced amniotic fluid embolism and you are planning future pregnancies, discuss your options with an obstetrician beforehand.
A real-life story of one mother’s experience of AFE
Danielle’s experience of AFE:
‘After being a single mother for two years to my eldest son, Ethan, I didn’t think I would be having any more children until much later in life.
‘However, I met my husband, Dylan, and a year later we were happily surprised with my pregnancy with our younger son, Oliver.
‘I was going to try VBAC (vaginal birth after a cesarean section) and had a healthy pregnancy with no concerns from my OB. Yet, my husband and I both had recurring nightmares of me dying on the table. I told Dylan they were just our subconscious reflecting our anxiety.
‘I never would have thought, at 25 years old, in one of the wealthiest states in the US, that I would be in danger of dying in childbirth. It’s just not something discussed—similarly to how much breastfeeding hurts, or how you would rather walk on hot coals than pee for the nurse after a cesarean section.
‘The week before I was due with Oliver I had contractions that brought me to my hands and knees. But no dilation. My OB decided to schedule a cesarean section, and—though to this day she doesn’t understand why—she ordered my blood to be on hold in the OR. She had told me she ordered it “just in case” even though I was healthy and had a great pregnancy. That decision is one coincidence of many that day that saved my life.
‘The day came for my scheduled cesarean section—3 February 2017— and Dylan and I went excitedly to our check in. I had a feeling that I wouldn’t be seeing my beautiful boys again. I asked Dylan to take a video of me for our boys. It was awkward, and I stumbled through it not knowing why I was doing it.
‘The nurse came in and told me that the OB scheduled had changed and I would be getting one that typically teaches at USC. We shrugged, as I felt any would be better than having to go home and reschedule.
The surgery went well, until they pulled my baby Oliver out of me. I began fading. I remember wanting to speak, but not being able to. Wanting to take in a larger breath, but not being able to. The nurse and the anesthesiologist noticed and took me to the PACU to monitor me.
‘I have been told that I was holding baby Oliver when they noticed my hemorrhaging. They had to push on my abdomen where I had the incision to measure the loss of blood. I began having tremors so badly they had to hold me down to get accurate blood pressure.
‘I was awake for everything but remember finer details rather than bigger pictures. I remember reading my vitals when I turned to the nurse taking my blood pressure and my BP being 36. I remember telling my husband he needed to sit with the baby and eat something. I remember understanding they were going to take me back in to take my uterus, and that I looked the NP in the eye and shook my head in a silent beg.
‘I remember the pain ripping through me, as I lifted my hips with the same abdomen that had been cut into and then pushed for an hour for the OB to save my uterus. I remember the OB coming into my room in the ICU letting me know that I should never have another child, because the stress on my heart and lungs would be too much. I was later told I had to have four bags of blood and one bag of platelets.
‘It wasn’t until the next day that I was told I had an amniotic fluid embolism that had—thankfully—gone to my lungs. The only reason I survived was all the coincidences. The blood on hand from my OB. The OB from USC who knew what an AFE was. The nurse and anesthesiologist noticing my being out of it in the OR.
‘The month after, I was diagnosed with PTSD and PPD. I began researching AFE and general maternal health. It was cathartic for me. It only took me another few months to go back to school to begin prerequisites for nursing school.
‘Now, almost two years later, I am about to apply for nursing school with plans to continue my education to go into research. I am eternally grateful to the men and women who saved my life, and to the AFE Foundation that helped save my mental health.
With the AFE Foundation, I found a group of women who understand when the little things, or the big, make me relive the trauma, or spark frustration or anger at the unfairness, and the survivor’s guilt I feel at times.
‘Now, I look at that video I made for the boys and I can laugh at how awkward it is—I was never one for being in front of the camera. Now, I can look at the pictures of my battered and bruised body after the hospital and feel grateful rather than angry.
‘Having an AFE sparked my passion for maternal health and research. I continue to believe I am here for a reason and try my best to live each moment with gratitude. Love every second of your most normal, boring day’.
The AFE Foundation is currently the only organisation that provides support, information and research studies for women and their families.
The AFE foundation discusses signs and symptoms, possible cause, impacts on the baby, risk factors, diagnosis, organ failure and mortality rates.They also provide a patient registry.
There is no doubt having had an amniotic fluid embolism can be a life threatening event. Because there is so much trauma associated with this condition, seeking support from the AFE Foundation is a vital part of recovery.
Please see the link below for more information: