Chorionic Villus Sampling (CVS)
Chorionic Villus Sampling (CVS)
Chorionic villus sampling (CVS) is a diagnostic genetic testing procedure used to detect the presence of certain genetic defects or diseases in a fetus during pregnancy. It involves taking a sample of chorionic villi cells from the placenta and testing them for the presence of genetic anomalies.
Preparation for CVS
In preparation for CVS, the doctor will discuss the procedure and risks with the patient. It is important for the patient to understand the procedure and potential risks, as well as any other health issues that may be present.
The doctor will also review the patient’s medical history and check for any potential health risks due to the CVS. The doctor may order additional tests, such as ultrasounds or blood tests, to gain more information about the fetus.
CVS Procedure
CVS is typically performed between the 10th and 13th week of pregnancy. During the procedure, the doctor will use an ultrasound to locate the placenta and determine the position of the fetus. A thin, flexible tube with a needle connected to a syringe is then inserted through the patient’s abdomen, guided by the ultrasound. The needle is used to collect a sample of chorionic villi cells from the placenta. The sample is then sent to a laboratory for analysis.
Types of CVS
There are two types of CVS procedures. Transabdominal CVS is performed by inserting the needle through the abdominal wall. Transcervical CVS is performed by inserting the needle through the neck of the uterus.
Risks of CVS
CVS carries a slight risk of miscarriage, infection, or injury to the fetus. Other risks include premature birth, preterm labor, and stillbirth. In very rare cases, CVS can also result in structural damage to the fetus, such as cleft palate or heart defects.
Why CVS Should be Performed
CVS is used to detect genetic abnormalities in the fetus, such as Down syndrome, cystic fibrosis, and neural tube defects. The procedure can also be used to detect chromosomal abnormalities, such as aneuploidy. Aneuploidy is an abnormality where the fetus has an extra copy of a chromosome, or is missing a chromosome. CVS is most often used when the mother is at elevated risk of carrying a baby with an abnormality.
When CVS Should be Performed
CVS is typically performed between the 10th and 13th week of pregnancy. The best time to perform CVS will vary from patient to patient, depending on the individual’s medical history, the risk of carrying a baby with an abnormality, and other factors. A doctor should be consulted to determine the best time to perform CVS.