Patient's question:
My wife is about 18 weeks pregnant and has been found to be high-risk. An amniocentesis needs to be done.Doctor's answer:
Amniocentesis is a method of prenatal diagnosis. Amniocentesis for Down syndrome screening diagnosis is recommended when a high-risk diagnosis of Down syndrome is confirmed in the early stage. This procedure is generally suitable for prenatal diagnosis during 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 volume, which will not cause the uterus to suddenly shrink and lead to miscarriage. Additionally, this period has the highest proportion of active cells in the amniotic fluid, with high cell culture viability. These 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 DNA-based 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 should be taken the day before the procedure. Empty the bladder completely 10 minutes before the procedure. If you have had a cold, fever, skin infection, or other abnormalities within the past 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 noted, 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. The first three days should involve bed rest, and the next four days should involve resting at home, avoiding strenuous exercise, shopping, housework, and heavy lifting.