What is amniocentesis
Release time : 07/26/2025 09:30:01
For pregnant women, knowledge of the amnion is very important, after all, the baby is protected in various ways within their own body, as if it were a large protective barrier, constantly guarding against external harm.
Amniocentesis is a common prenatal examination procedure. So, what does amniocentesis entail? What is its purpose? What are the risks associated with amniocentesis? For expectant mothers, especially first-time mothers, understanding amniocentesis may be challenging due to their infrequent exposure to prenatal screening knowledge. What exactly is amniocentesis? Amniocentesis is the most commonly used invasive prenatal diagnostic technique.
Doctors can extract free cells from the fetus's skin, gastrointestinal tract, and urinary system through amniocentesis, analyze these free cells further to check whether the fetus's chromosome is abnormal.
Surgery is usually performed between 16 and 22 weeks of gestation, at a time when the proportion of live cells in amniotic fluid is relatively high.
The extraction of amniotic fluid is mainly used to analyze fetal chromosomal components, and it is the most important and common one for Down syndrome.
Some single-gene diseases, such as sea anemia type B, hemophilia, etc., can also be diagnosed by testing the genes (DNA composition) in amniotic fluid cells.
What is the use of amniocentesis? Amniocentesis is a common test item during pregnancy tests, but many people don't know what the purpose of this test is.
It's important to understand the role of amniocentesis.
1. Understanding fetal chromosome abnormalities: Amniotic fluid cell culture and cytogenetic analysis can be used to detect the presence or absence of fetal chromosome abnormalities, including common aneuploidies (chromosome number or structural abnormalities) and sex chromosome aneuploidies (sex chromosome numbers or structural abnormalities).
2. Amniotic fluid cytogenetic examination involves centrifuging the amniotic fluid sample directly onto a slide, followed by routine processing and staining. Under a microscope, the X and Y chromosomes in the amniotic fluid cells can be used to diagnose and treat genetic disorders associated with recessive traits.
3. Congenital metabolic disorders, culture of amniotic fluid cells and determination of various enzymes to determine whether the fetus has a metabolic disorder.
4. Prenatal diagnostics for genetic diseases involve directly extracting amniotic cells from the fetus, and then detecting them via labeled specific probes. This allows the presence or absence of a gene, partial deletions, or mutations to be identified.
The risk level of amniocentesis has been continuously reduced with the advancements in medical technology.
Regarding the amniocentesis in prenatal examination, although it is a very mature technology, it also has certain risks.
What are the risks of amniocentesis? The procedure has been used for prenatal diagnosis for 30 years, and its accuracy and safety have been recognized by the medical community.
The difficulty of amniocentesis varies from person to person, primarily related to the position of the placenta, the position of the fetus, the amount of amniotic fluid at the site of the needle, and the fetal activity.
Approximately 2% to 3% of pregnant women will experience slight uterine contractions and vaginal bleeding after a dilation and curettage, which usually resolves with rest or treatment.
Only about 0.5% of pregnant women have a placenta that ruptures or causes miscarriage.
The minimal invasiveness of the procedure is due to ultrasound guidance.
In addition, amniocentesis for prenatal diagnosis is performed at gestational ages of 16 to 22 weeks.
At this time, the fetus's body and limbs have already developed, thus it does not cause fetal abnormalities.
Is amniocentesis painful? Talking about the procedure, many people are quite fearful, let alone amniocentesis, where a needle is inserted into the pregnant woman's body.
Actually, with the development of medical technology, there has been a significant improvement in the procedure of amniocentesis. So, is it painful? The amniocentesis procedure is an invasive examination performed by a professional physician.
To achieve better puncture effect, doctors will do ultrasonic positioning before puncturing, and choose the most suitable puncture site under B-ultrasound monitoring to avoid the possibility of injury to the fetus is very small.
Doctors operate very fast.
Most people only feel slight pain during puncture.
Similar to acupuncture, most people can endure it without tension or fear.
Before undergoing amniocentesis, you must communicate thoroughly with your doctor to understand the purpose and significance of the procedure, as well as the entire process involved.
If you have a fever, upper respiratory tract infection or early miscarriage, please tell the doctor in person. During surgery, do not be overly nervous and anxious; muscle atrophy will increase the difficulty of the operation. After surgery, follow the doctor's advice to rest for 1-2 days, avoid strenuous exercise and sexual activity. If you experience symptoms such as redness of the needle, abnormal secretions, abdominal tension, contractions, fever, etc., seek medical attention immediately.
When is amniocentesis performed? The timing for amniocentesis is critical, and only within this window can the results be optimally obtained. Amniocentesis is a prenatal examination technique that involves collecting amniotic fluid samples from the uterus to detect abnormalities in fetuses during pregnancy.
At the same time, amniocentesis can also diagnose fetal blood type, thereby avoiding the occurrence of fetus-mother blood type incompatibility. Additionally, if the mother has metabolic diseases, amniocentesis can be used to diagnose whether the fetus has hereditary traits.
The optimal time for amniocentesis in antenatal diagnosis is between the 18th and 22nd week of gestation.
At this time, the fetus is small with a large amount of amniotic fluid, and the fetus floats in the amniotic fluid, surrounded by extensive amniotic fluid, and puncture extraction of amniotic fluid is performed.
When it is not easy to stab the fetus, the abortion rate is also lowest.
The specific timing must be based on the specific circumstances of the pregnant woman. If the optimal gestational age is exceeded, cord blood puncture can be used for diagnosis.
The medical part covered in this article is for reading and reference only.
Should there be any discomfort, it is advised to seek medical attention immediately. The diagnosis and treatment should be based on a face-to-face consultation with a physician.