Postpartum embolism

Many people think that the most dangerous time for pregnant women is the late pregnancy and childbirth. In their opinion, all they need to do after delivery is good care. But in fact, this is not the case. Pregnant women are more likely to have some embolism after delivery, such as pulmonary embolism and lower limb embolism. These are very harmful to the mother, and sometimes even fatal in severe cases. So, what methods should we use to avoid postpartum embolism?

Amniotic fluid embolism refers to a serious complication during delivery in which amniotic fluid suddenly enters the maternal blood circulation, causing acute pulmonary embolism, anaphylactic shock, disseminated intravascular coagulation, renal failure or sudden death. The incidence rate is 4/100,000 to 6/100,000. Amniotic fluid embolism is caused by the entry of tangible substances (fetal vellus, keratinized epithelium, vernix caseosa, meconium) and procoagulant substances in the contaminated amniotic fluid into the maternal blood circulation. Recent studies have shown that amniotic fluid embolism is mainly an allergic reaction. After the amniotic fluid enters the maternal circulation, it causes a series of allergic reactions in the mother to fetal antigens. Therefore, it is recommended to name it "pregnancy allergic reaction syndrome."

Causes

Amniotic fluid embolism often occurs during delivery or rupture of membranes, but can also occur after delivery. It is more common in full-term deliveries, but can also be seen during mid-term induction of labor or forceps curettage. Most cases occur suddenly and are serious.

The occurrence of amniotic fluid embolism usually requires the following basic conditions: increased pressure in the amniotic cavity (excessive uterine contractions or tonic uterine contractions); rupture of fetal membranes (2/3 of which are premature rupture of membranes and 1/3 are spontaneous rupture of membranes); open veins or sinuses at the site of cervical or uterine injury.

Amniotic fluid embolism usually has the following causes: most of them are multiparous women; most of them have a history of premature rupture of membranes or artificial rupture of membranes; it is common in excessive uterine contractions or improper use of oxytocin; amniotic fluid embolism is more likely to occur in early placental abruption, placenta previa, uterine rupture or surgical delivery.

Clinical manifestations

Amniotic fluid embolism develops rapidly, and the patient often dies before many laboratory tests can be done, so early diagnosis is extremely important. In most cases, some prodromal symptoms often appear first at the onset of the disease, such as chills, irritability, cough, shortness of breath, cyanosis, vomiting, etc. If the amount of amniotic fluid intrusion is very small, the symptoms are mild and sometimes recover on their own. If the amniotic fluid is turbid or the amount intrusion is large, typical clinical manifestations will appear one after another.

1. Respiratory and circulatory failure

According to the condition of the disease, it is divided into two types: explosive type and chronic type. The fulminant type is a prodromal symptom, followed soon by dyspnea and cyanosis. Acute pulmonary edema may cause coughing, pink foamy sputum, rapid heart rate, and decreased or even absent blood pressure. In a few cases, the patient died of cardiac and respiratory arrest after only a scream. The symptoms of slow respiratory and circulatory system are mild, or even no obvious symptoms. It is not diagnosed until postpartum bleeding and blood coagulation occur.

2. Systemic bleeding tendency

Some patients with amniotic fluid embolism survive the period of respiratory and circulatory failure after rescue, but then develop DIC, which is manifested as systemic bleeding tendency with heavy vaginal bleeding as the main feature, such as mucosal, skin, pinhole bleeding and hematuria, and the blood does not coagulate. However, some cases of amniotic fluid embolism lack clinical symptoms of the respiratory and circulatory systems. The main manifestation of the disease is difficult to control vaginal bleeding after delivery, which can easily be mistaken for postpartum hemorrhage caused by uterine atony.

3. Multi-system organ damage

This disease damages all organs in the body, and the kidneys are the most commonly damaged organs besides the heart. Due to renal hypoxia, patients may experience oliguria, anuria, hematuria, and azotemia, and may die from renal failure. When the brain is hypoxic, patients may become irritable, have convulsions, and become comatose.