Amniotic fluid is well-known—the fetus develops within it during pregnancy. Amniocentesis, simply put, involves inserting a needle into the amniotic sac to withdraw a small sample of fluid for testing.
Amniocentesis is a method of prenatal diagnosis, typically suitable for mid-pregnancy screening. Amniotic fluid is contained within the amniotic cavity. The optimal time for amniocentesis is between 16 and 24 weeks of gestation. At this stage, the fetus is smaller, amniotic fluid volume is relatively abundant, and the fetus floats within the fluid surrounded by a wide amniotic fluid cushion. This configuration minimizes the risk of fetal injury during the procedure.
Prior to amniocentesis, an ultrasound is performed to confirm fetal position and condition, preventing accidental injury. After selecting the insertion site, the skin is disinfected, a sterile drape is applied, and local anesthesia administered. A lumbar puncture needle with a needle core is then inserted vertically into the chosen location. Two distinct "hollow" sensations indicate penetration through the abdominal and uterine walls. The needle core is removed, and 2 mL of amniotic fluid is aspirated using a 2 mL syringe.followed by 20 ml of amniotic fluid using a 20 ml empty syringe.
After aspiration, the needle is removed, and sterile gauze is applied with pressure for 2-3 minutes. The mother should rest in bed for 2 hours afterward. Extreme caution is required during bathing to avoid touching the site.