Chorionic Villus Sampling (CVS)
Chorionic villus sampling (CVS) is a test done during early pregnancy that can find certain problems with your Reference baby (fetus) Opens New Window. It is generally done when either you or the father has a disease that runs in the family (Reference genetic disorder Opens New Window). It may also be done when you are over age 35—being over 35 increases your chance of having a baby with a Reference chromosome Opens New Window defect.
Reference Chorionic villi Opens New Window Reference Opens New Window are tiny finger-shaped growths found in the Reference placenta Opens New Window. The genetic material in chorionic villus cells is the same as that in the baby's cells. During CVS, a sample of the chorionic villus cells is taken for Reference biopsy Opens New Window. The chorionic villus cells are checked for problems. The procedure is generally done late in the first trimester, most often between the 10th and 12th weeks.
The chorionic villus sample can be collected by putting a thin flexible tube (catheter) through the vagina and cervix into the placenta. The sample can also be collected through a long, thin needle put through the belly into the placenta. Reference Ultrasound Opens New Window is used to guide the catheter or needle into the correct spot for collecting the sample.
If you have a family history of certain diseases, CVS can be used to find genetic disorders, such as Reference Tay-Sachs disease Opens New Window or Reference hemophilia Opens New Window. It can also find chromosomal birth defects, such as Reference Down syndrome Opens New Window. CVS cannot find Reference neural tube defects Opens New Window and it cannot be used to see if the baby's lungs are mature.
Chorionic villus sampling can be done earlier in pregnancy (at 10 to 12 weeks) than Reference amniocentesis Opens New Window (usually done at 15 to 20 weeks). This allows you to know the health of your baby and make an earlier decision whether to continue or end the pregnancy. Results of CVS can be available sooner than amniocentesis results.
|By:||Reference Healthwise Staff||Last Revised: Reference April 4, 2012|
|Medical Review:||Reference Sarah Marshall, MD - Family Medicine
Reference Siobhan M. Dolan, MD, MPH - Reproductive Genetics