Patient's question:
My wife is about 18 weeks pregnant and has been diagnosed with high risk. She needs to have an amniocentesis.Doctor's answer:
Amniocentesis is a method of prenatal diagnosis. Amniocentesis for Down syndrome screening diagnosis is recommended by doctors when a high-risk diagnosis of Down syndrome is confirmed in the early stage. It is generally suitable for prenatal diagnosis in the second trimester of pregnancy. The optimal time for amniocentesis to extract amniotic fluid for prenatal diagnosis is between weeks 16 and 20 of pregnancy. At this stage, the fetus is small, and there is relatively more amniotic fluid. The fetus floats in the amniotic fluid, surrounded by a wide band of amniotic fluid. When extracting amniotic fluid with a needle, it is less likely to injure the fetus. Extracting 20 milliliters of amniotic fluid accounts for only 1/20 to 1/12 of the total amount, which will not cause the uterine cavity to shrink suddenly and lead to miscarriage. Moreover, this period has the highest proportion of active cells in the amniotic fluid, with a high cell culture survival rate. The cells can be used for slide preparation, staining, fetal chromosome karyotype analysis, chromosome genetic disease diagnosis, and gender determination. Amniotic fluid cells can also be used for genetic disease diagnosis and metabolic disease diagnosis. Measuring alpha-fetoprotein in the amniotic fluid can also diagnose open neural tube defects in the fetus.Generally, an appointment is required before the examination. Abstinence from sexual activity is recommended for three days before the procedure. A shower is recommended the day before the procedure. Empty your bladder completely 10 minutes before the procedure. If you have had a cold, fever, skin infection, or other abnormalities within 3 to 7 days before the procedure, please inform the doctor during pre-procedure registration. If you have a history of allergies, special diseases, or other conditions that need to be mentioned, please inform the doctor during pre-procedure registration.
After the procedure, you must rest for at least 2 hours before taking a taxi home. Out-of-town patients are advised to stay in the city overnight. Do not shower for at least 72 hours after the procedure. Rest as much as possible and try to rest for a week. Rest in bed for the first three days and stay at home for the next four days. Avoid strenuous exercise, shopping, housework, and heavy lifting during this period.