What is amniotic fluid embolism? How to prevent it?

Amniotic fluid embolism is the most dangerous thing during childbirth. Although the probability of this happening is very small, once it happens, the consequences are very serious. So what is amniotic fluid embolism? How to prevent amniotic fluid embolism? Let's learn about it together~

Amniotic fluid embolism is difficult to predict and has a high mortality rate

The so-called "amniotic fluid embolism" is when amniotic fluid enters the blood circulation of pregnant women, causing complications such as acute embolism, anaphylactic shock, disseminated intravascular coagulation, renal failure or sudden death. Its incidence rate is only about one in 20,000 worldwide, but it is almost impossible to prevent or predict the occurrence of this situation in advance. Once it occurs, the mortality rate is extremely high, with the mortality rate of pregnant women and fetuses as high as 80%.

What causes amniotic fluid embolism?

What causes amniotic fluid embolism? At present, the medical community is still unclear about the cause of amniotic fluid embolism. It may be related to excessive pressure in the amniotic cavity, open blood sinuses, rupture of fetal membranes, etc.:

1. The pressure in the amniotic cavity membrane is too high

After delivery, especially during the second stage of labor, the pressure in the amniotic cavity increases (up to 100-175 mmHg) and significantly exceeds the venous pressure. Therefore, the amniotic fluid may be squeezed into the damaged microvessels and enter the maternal blood circulation.

2. Opening of blood sinuses

Cervical lacerations caused by various reasons during delivery can allow amniotic fluid to enter the maternal blood circulation through damaged blood vessels. When placenta previa, placental abruption, or rupture of the blood sinus at the edge of the placenta occurs, amniotic fluid can also enter the maternal blood circulation through damaged blood vessels or blood sinus behind the placenta. During cesarean section or curettage, amniotic fluid can also enter the maternal blood circulation from the blood sinus at the placenta attachment, causing amniotic fluid embolism.

3. Rupture of membranes

Most amniotic fluid embolism occurs after the fetal membranes rupture, and amniotic fluid can enter the maternal blood circulation from the damaged small blood vessels of the uterine decidua or cervical canal. During cesarean section, amniotic fluid can enter the maternal blood circulation from the surgical incision.

In summary, advanced primiparas, multiparas, excessive uterine contractions, premature labor, premature rupture of membranes, placenta previa, uterine rupture, and cesarean section are the predisposing factors of amniotic fluid embolism.

How to prevent amniotic fluid embolism

To prevent amniotic fluid embolism, first of all, you should do regular prenatal checkups. Secondly, if you feel irritable or have chills during labor, you should tell your doctor immediately. This includes the following 6 points:

1. Prenatal examinations reveal factors that may lead to the disease

90% of placenta previa can be diagnosed by B-ultrasound examination, and placental abruption can be detected early by using labor monitoring devices. These two abnormalities may be the cause of amniotic fluid embolism.

2. Strengthen prenatal education and pay attention to predisposing factors

Women over 30 years old, those who have given birth prematurely or after-term, and multiparous women, especially those with premature rupture of membranes or hypoplastic uterine body or cervix, are prone to amniotic fluid embolism.

Those with inducing factors should be closely observed to increase vigilance against amniotic fluid embolism, such as cesarean section, placenta previa, early placental abruption, and precipitous delivery.

3. Tell your doctor if you feel any discomfort

During the delivery process, if you experience discomfort such as chest tightness, irritability, chills, etc., you should tell your doctor immediately so that the doctor can do his best to deal with it as soon as possible.

4. Choose cesarean section in time

If amniotic fluid embolism occurs during the first stage of labor, the baby cannot be delivered immediately. Although the condition improves after rescue, it may still worsen because the cause has not been removed. If necessary, cooperate with the doctor to perform a cesarean section and end the delivery as soon as possible to avoid the danger of uterine rupture.

5. Avoid birth injuries, uterine rupture, cervical laceration, etc.

(1) Avoid excessive uterine contractions during childbirth

Excessive uterine contraction increases the intrauterine pressure, which may cause the uterine lower endometrium to rupture, and amniotic fluid enters the mother's body through the gap during uterine contraction. Appropriate sedatives and uterine contraction inhibitors should be given to slow down uterine contractions.

(2) Strictly follow the indications for the use of oxytocin

Use oxytocin appropriately and conduct necessary observations. During labor, if the uterus contracts too strongly, the mother should cooperate with the doctor to use sedatives to weaken the contraction of the uterus to prevent uterine rupture.

(3) Strictly follow the indications for cesarean section

When the water breaks, use gauze to protect the edges of the incision, and protect the open blood vessels on the uterine incision before puncturing the amniotic membrane.

(4) Strictly follow the indications for artificial rupture of membranes.

Artificial rupture of membranes is not performed simultaneously with membrane stripping to reduce damage to small blood vessels in the cervical canal and to avoid rupturing membranes during uterine contractions.

(5) During mid-term labor induction with clamps, the membranes are ruptured first and the amniotic fluid is allowed to drain, followed by clamping and the use of oxytocin.

6. Observe the fourth stage of labor carefully to detect shock that is inconsistent with bleeding in a timely manner.