What You Should Know About Chorionic Villus Sampling
With proper screening, many women can learn if their child has a birth defect and be in a better position to make an informed decision about that child. While the chorionic villus sampling (CVS) test is less common than amniocentesis, it's also an important test for detecting genetic disorders. It's important know what this screening procedure involves, what it can help you find, and what the risks involved are.
About The Chorionic Villus Sampling (CVS) Test
Chorionic villus sampling (CVS) is a diagnostic test that is usually performed 11-13 weeks into your pregnancy, but it can also be performed later in your pregnancy as well. A doctor will remove a small amount of tissue from your baby's placenta. Both the baby and the placenta are developing from the same cells, so doctors can screen the placenta cells and understand if the baby is suffering from certain genetic defects.
The CVS test is most important for screening of Down's syndrome, and most women who perform the test do it to screen for this complication. However, the CVS test can also screen for other genetic disorders as well, including thalassemia, Tay Sachs diseases, and sickle cell anemia.
CVS is often highly recommended for older women or families with a history of certain genetic diseases. Women often have the CVS early in the pregnancy to decide if they want to terminate the pregnancy if certain genetic abnormalities are detected.
Having A CVS Test
The actual test first involves an ultrasound of your body to determine where the fetus is. After a local anesthetic is applied, a long double-barreled needle will then be placed through your abdominal wall and guided into your uterus. Once inside, the needle will take a sample of the chorionic villi, which are a part of the placenta. The sample will then be analyzed for defects.
Risks And Disadvantages of the CVS Test
The CVS is an invasive test, and because of that, carries a certain amount of risks. Be sure to consider the following information:
- CVS is performed earlier than amniocentesis but carries a slightly higher risk of miscarriage.
- If CVS is done very early, there is an increased risk that your baby may develop a complication that lead to abnormal growth of its limbs.
- There are some circumstances where your baby's placental tissue contains mosaic cells. These cells may show abnormalities that aren't actual present in the actual baby, which means the CVS test is not considered always completely accurate.
Ultimately, the CVS test is a valuable tool for genetic screening, but it's best you understand the risks before you move forward with this screening yourself.