Chorionic Villus Sampling (CVS)

• Normal results from chorionic villus sampling (CVS) do not guarantee that your baby will be healthy. CVS can't find Reference neural tube defects Opens New Window.
• Amniocentesis (which is usually done later in the pregnancy than CVS) can also be used to find other diseases of the fetus, such as neural tube defects. If CVS does not show clear results, amniocentesis may need to be done.
• CVS is done if you are at high risk for having a baby with a chromosomal birth defect (such as Down syndrome) or a family genetic disease (such as Tay-Sachs disease or hemophilia). The benefits of this test often outweigh the risks. Genetic diseases and birth defects can be found earlier in pregnancy by CVS than by amniocentesis. This allows you to make an earlier decision whether to continue or end the pregnancy.
• The results of CVS may vary depending on how the sample was taken.
• If you have a vaginal infection (such as a Reference vaginal yeast infection Opens New Window or Reference genital herpes Opens New Window), a belly procedure will be used instead of a vaginal procedure.
• CVS causes bleeding that could lead to mixing of your blood and your baby's about half of the time. If you have Rh-negative blood, you will be given the Rh immunoglobulin vaccine (such as RhoGAM) to prevent Reference Rh sensitization Opens New Window which could harm your baby if he or she has Rh-positive blood.

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