Patient's question:
Obstetrician, thank you for your previous answer! I would like to ask you again, after 18 weeks of pregnancy, if I go to the hospital for an amniocentesis test, is this test highly accurate for screening Down syndrome? It has been a year since then, and I am pregnant again now, but the doctor said that after 18 weeks, an amniocentesis needs to be performed for testing. What is the process like? Is it done by inserting a needle through the abdomen, or through the vagina? I'm so worried! Is this procedure highly risky for the safety of the fetus and myself? Is this test required for all prenatal check-ups? Is the test method for this result the same as for chromosome testing? How long does it usually take to get the results? I'm so worried! Lastly, I would like to ask about...Doctor's answer:
Amniocentesis can be used for fetal chromosome karyotype analysis, chromosomal genetic disease diagnosis, and gender determination. It can also be used to diagnose genetic diseases and metabolic diseases using amniotic fluid cell DNA. Measuring alpha-fetoprotein in amniotic fluid can also diagnose fetal open neural tube defects, among others. This is done to screen for chromosomal abnormalities and reduce the birth of mentally retarded or cretinous children. Amniocentesis is not scary. The main method involves using a needle to extract a certain amount of amniotic fluid, which is similar to a muscle injection. Therefore, pregnant women do not need to be too nervous, and currently, amniocentesis is performed under ultrasound monitoring, unlike the "blind" method in the past. Therefore, amniocentesis is not dangerous for the fetus. However, for pregnant women with high-risk factors for miscarriage, there may be a risk of miscarriage. For example, pregnant women with uterine fibroids or those with early pregnancy symptoms such as frequent uterine contractions and vaginal bleeding.Generally, amniocentesis does not require fasting, but it is best to go in the morning. After registering, the procedure cannot be immediately performed, as some tests need to be done first, such as measuring body temperature, listening to the fetal heartbeat, and ultrasound to determine the position of the placenta, fetal condition, and amniotic fluid status. After the tests, the decision can be made whether to proceed with the.
The steps for amniocentesis are as follows: Pregnant women with indications first undergo an ultrasound to determine the position of the placenta and fetal condition, avoiding accidental injury to the placenta. After selecting the needle insertion point, the skin is disinfected, a sterile towel is placed, and local anesthesia is administered. A spinal needle with a needle hub is inserted vertically at the selected point. There are two "hollow" sensations as the needle passes through the abdominal wall and uterine wall; the needle hub is then removed. Using a 2-mL syringe, 2 mL of amniotic fluid is aspirated and discarded, as this portion may contain maternal cells. Then, a 20-mL syringe is used to aspirate 20 mL of amniotic fluid, which is divided into two sterile test tubes and sealed. The needle is removed, sterile gauze is placed over the site, and pressure is applied for one minute. The pregnant woman is then advised to rest for two hours.