How to do amniocentesis? Who can't do amniocentesis?

Expectant mothers must have heard of this term. The main function of amniocentesis is to determine whether the baby is deformed. So how should amniocentesis be done? Who should not do it? Let us introduce it below!

How to perform amniocentesis?

Acupuncture in the abdomen to suck out amniotic fluid

Amniocentesis, as the name suggests, is to insert a needle into the pregnant mother's belly to draw out a certain amount of amniotic fluid for testing.

The specific process is as follows: pregnant women need to do B-ultrasound examination first to determine the position of the placenta and the condition of the fetus to avoid accidental injury to the placenta. After selecting the insertion point, disinfect the skin, spread a disinfectant towel, apply local anesthesia, and then use a lumbar puncture needle with a needle core to vertically pierce the selected point; there will be two empty sensations when the needle passes through the abdominal wall and uterine wall, and the needle core is removed; use a 2 ml syringe to aspirate 2 ml of amniotic fluid and discard it. This section of amniotic fluid may contain maternal cells; then use a 20 ml empty needle to aspirate 20 ml of amniotic fluid, respectively, in 2 sterile test tubes, cover them; remove the needle, cover with sterile gauze, press for 2-3 minutes, and the pregnant woman rests in bed for 2 hours.

When is the safest time to do amniocentesis?

The best time for amniocentesis is 18 to 22 weeks of pregnancy

The best time to draw amniotic fluid for prenatal diagnosis is 18 to 22 weeks of pregnancy. Because the fetus is small at this time, the amniotic fluid is relatively abundant, and the fetus floats in the amniotic fluid, surrounded by a wide amniotic fluid belt. When drawing amniotic fluid with a needle, it is not easy to injure the fetus. Moreover, drawing 20 ml of amniotic fluid only accounts for 1/20 to 1/12 of the total amount of amniotic fluid, which will not cause the uterine cavity to suddenly shrink and lead to miscarriage.

Are there risks with amniocentesis?

The risk of fetal injury or intrauterine infection is less than 1/200

Currently, amniocentesis is basically performed under visual B-ultrasound. It is generally safe, but there are still certain risks, such as the risk of causing maternal injury, fetal injury, placenta and umbilical cord injury, amniotic fluid leakage, miscarriage or premature birth, and intrauterine infection, but the proportion does not exceed 1/200. Its total risk rate, that is, the risk of causing fetal miscarriage, generally does not exceed 5%-1%.

Does amniocentesis hurt?

Tolerable pain or no pain

This operation does not require anesthesia. Compared with amniocentesis, anesthesia makes women feel more painful. Therefore, performing amniocentesis without anesthesia will cause some pregnant women to feel a little bit of stimulation in their abdomen and feel different degrees of urgency or pressure. Some pregnant women may not feel any discomfort. Most pregnant women will feel a little pain during the puncture. This pain is very weak and tolerable. Therefore, for this question, it can only be said that it varies from person to person.

Who should not undergo amniocentesis?

For an expectant mother, amniocentesis is not a strange word. The best time to do amniocentesis is between the 18th and 23rd weeks. It can determine whether the fetus has teratogenicity or genetic metabolic diseases, which is helpful for eugenics. However, some pregnant women are not suitable for amniocentesis because during amniocentesis, a needle needs to be inserted into the pregnant woman's uterine cavity to absorb a small amount of amniotic fluid. So who can't do this test?

People with signs of miscarriage

Pregnant women with weak bodies are not suitable for amniocentesis to prevent miscarriage and threaten the life of the fetus. If the pregnancy is very long, the fetus is basically formed. Even if amniocentesis is performed, if any abnormality is found, it will have a very serious impact on the child and the pregnant woman. Some pregnant women are even more sensitive and will cause uterine infection after amniocentesis. Therefore, pregnant women like the above are not suitable for amniocentesis.

Who is suitable for this?

Doctors do not recommend amniocentesis for every pregnant woman. Generally speaking, amniocentesis is required for pregnant women who are elderly or have high-risk signs in Down syndrome screening to ensure that the fetus does not have some potential teratogenic or genetic diseases. For example, if there are family congenital metabolic disorders, chromosomal abnormalities, gene defects, etc., amniocentesis is necessary. In addition, when a pregnant woman has rubella virus, amniocentesis can be used to determine whether the fetus has signs of infection.

Risks of Amniocentesis

At present, this operation is relatively risky. If the doctor is not experienced enough, it is easy to cause the operation to fail, causing uterine infection, bleeding in pregnant women, or even miscarriage. This is one of the reasons. In addition, the diagnosis technology for genetic defects is not yet mature, so even if the amniocentesis operation is successful, the reliability of the results cannot be guaranteed. However, in a regular maternal and child hospital, you can still have a relatively safe examination.

Amniocentesis precautions

1. If you have a history of allergies or special diseases, or have had a cold, fever, skin infection, or other abnormalities 3 to 7 days before surgery, please inform the doctor during preoperative registration.

2. Please arrive at the hospital one hour in advance after lunch to rest and wait, and must be accompanied by family members.

3. No sexual intercourse is allowed three days before the operation; please take a shower one day before the operation; please urinate completely 10 minutes before the operation.

4. You can go home by car after sitting and resting for at least 2 hours after surgery. Do not bathe within 24 hours after surgery. If you have abdominal pain, bloating, vaginal discharge, bleeding, fever and other symptoms within three days after surgery, you need to go to the obstetrics and gynecology department of the hospital as soon as possible.

5. Do not have sex for half a month after surgery. Pay more attention to rest, avoid a lot of exercise, and avoid physical labor such as carrying heavy objects.