This procedure is typically performed in the outpatient setting by a team of providers. With ultrasound guidance, a needle is inserted into the abdomen at an angle through the muscle, into the uterus and into the<unk> iotic cavity. There are various methods to obtain samples including a single needle and double needle technique. These techniques have their own variations in how they are performed including guidance of needle insertion location, and angle of needle insertion. The collected<unk> iotic fluid is then submitted for laboratory testing for chromosomal abnormalities and the puncture site heals with time. Ultrasound evaluation Before the procedure is performed, the fetus is analyzed via ultrasound to determine if it is viable and for any abnormalities. The ultrasound determines the location of the placenta, fetal position and movements, and characteristics of the<unk> iotic fluid. This information is utilized to determine the type of needle used and how the procedure should be performed. Preparation The abdomen is treated and cleaned with antiseptic before the procedure. Sterile gel is also used on the abdomen before scanning with a sterile ultrasound probe. These measures are taken to reduce infection risk. The tools used in the procedure are coated with heparin to prevent clotting. Needle insertion With the aid of ultrasound guidance, a needle is inserted through the mother's abdominal wall, then through the wall of the uterus, and finally into the<unk> iotic sac. The physician then punctures the sac in an area away from the fetus and extracts approximately 20ml of<unk> iotic fluid. This procedure can be performed with a single needle or a double needle technique based on individualized patient factors and physician preference. From the 20 ml of<unk> iotic fluid, the first 2 ml is typically discarded due to mixture with maternal blood cells to ensure high quality fluid sampling. Post procedure recommendations and analysis If used for prenatal genetic diagnosis, fetal cells are separated by centrifugation from the extracted sample. The cells are grown in a culture medium, then fixed and stained. Under a microscope the chromosomes are examined for abnormalities. The most common abnormalities detected are Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Turner syndrome (monosomy X). The sample is also analyzed for fetal infection and for intra-amniotic inflammation through infection studies. After the procedure, the patient is instructed to take house rest for the initial 24 hours post-procedure however normal<unk> tivities are allowed such as personal hygiene. In regard to the fetus, the puncture seals and the<unk> iotic sac replenishes the liquid over the next 24–48 hours. One week after the procedure, the mother will have a follow up appointment for ultrasound analysis to confirm fetal viability and to assess healing of the puncture site.
Amniocentesis
Magnetogenetics
Fetal echocardiography
Fetal scalp blood testing
Chorionic villus sampling
Prenatal testing
Preimplantation genetic diagnosis
Obstetric ultrasonography