Advertisement
Chorionic villus sampling (CVS) is a diagnostic test performed between the 10th and 12th week of pregnancy in which a tiny sample of cells is removed from the placenta, cultured in a laboratory, and the DNA is examined for genetic content. Because the placenta is made up of cells that derive from the same fertilized egg as the fetus, it's an ideal resource for DNA that can reveal any genetic abnormalities in your developing baby (or for a paternity test). The advantage of CVS over amniocentesis is that you can have the test done much earlier (amnio is usually performed between 16 and 20 weeks).
While CVS can detect up to 200 different genetic defects with 98-99 percent accuracy (including Tay Sachs, cystic fibrosis, and hemophilia), it cannot detect neural tube defects such as spina bifida, which can be picked up by amniocentesis.
While CVS can detect up to 200 different genetic defects with 98-99 percent accuracy (including Tay Sachs, cystic fibrosis, and hemophilia), it cannot detect neural tube defects such as spina bifida, which can be picked up by amniocentesis.

More About this Book
YOU: Having a Baby: The Owner's Manual to a Happy and Healthy Pregnancy
Can I get a cavity filled while pregnant? Will avoiding spicy foods make my kid a picky eater? Can I really increase my baby's IQ while she's in utero? Whether you're pregnant for the first time,...
Continue Learning about Lab Tests
Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.